|Published on:||December 2nd, 2019|
|With:||Eric Miller, Prith Banerjee, & Mark Hindsbo|
In this episode, your host and Co-Founder of PADT, Eric Miller is joined by ANSYS CTO Prith Banerjee and VP/General Manager of the Design Business Unit Mark Hindsbo, for a discussion of their roles at the company, what trends they see coming from various industries working with simulation, and how ANSYS continues to help their customers by providing valuable solutions in response to those trends.
If you have any questions, comments, or would like to suggest a topic for the next episode, shoot us an email at email@example.com we would love to hear from you!
I was on the gondola up at Keystone for night-skiing a week ago, after a long day at Beaver Creek, because the last thing I am going to do at 3:00 pm is try to make it back to Denver, as everyone knows it’s hardly more than a parking lot at that point. As it gets later, there’s nothing like a solo gondola ride, however, a solo ride would stop this story right about now.
On the gondola, I overheard a conversation where one gentleman was discussing how he was unable to open the hatch of his vehicle when his skis are in his roof rack. That’s fair, I know older WRX wagons with the spoiler would not be able to open with skis on the roof no matter what, so I figured that was the case. It turns out, that was NOT the case. The reason his hatch would not open was that he orients the skis with the tails forward because it is ‘more aerodynamic’ that way… I was skeptical, but held my tongue, knowing that I had the tools at my disposal to investigate!
I decided to make a model that would allow me to simulate various conditions to get to the bottom of this. My initial hypothesis is that the addition of the ski rack and crossbars is what has the largest effect on aerodynamics, and orientation of the skis probably has a negligible effect after that. As a side note, I am solely concerned with aerodynamics in this case, and am not worrying about the amount of the ski’s base material that is exposed for a given orientation. I am of the mindset that tree trunks and hidden rocks on the mountain are more of a danger to your bases than small rocks on the highway anyway. If you are waiting to comment, “Just get a roof box!”, I understand as I own both a box and a rack at this point, and they both have their advantages, and I will not be exploring the aerodynamics of a box…
I was able to start by finding some faceted geometry of a Subaru Forester online (I’m from Colorado, can you tell?) and was able to import that into ANSYS Spaceclaim. Once in Spaceclaim, I was able to edit the faceted geometry to get nice exterior panel surfaces, which I then combined to get a single clean faceted exterior for the car.
After that, I used Spaceclaim to generate the remainder of the rack and skis, including crossbars, a ski rack, and a pair of skis (Complete with the most detailed bindings you have ever seen!). I made a combined part of the crossbars, rack, and skis for each one of my orientations, as this allows me to report the forces on each combined part during the simulation.
For the simulation, I used ANSYS Discovery Live, the newest tool from ANSYS that allows for instant and interactive design exploration. This tool lets me actively add my CAD geometry and shows results in realtime. I was able to start with just the car and then add and swap my ski/rack geometry with simple button clicks. With traditional simulation tools, I would have needed to create a mesh for each one of these cases, analyze them one at a time, and the post-process and compare results after the fact. After launching Discover Live, it’s as easy as selecting the type on analysis I want to run.
Once I have selected ‘Wind Tunnel’ for my solution, I can select my geometry, and then am prompted for the direction of flow, as well as selecting the ‘floor’ of my domain. Once that is done, results show up on the screen instantly. I only needed to modify the flow velocity to ~65 mph. I am most interested in the force on the faces of the combined crossbars, rack, and skis in each orientation, so I created Calculations for each one, which is done by simply selecting the part and using the popup toolbar to create the graph.
I was already off and running. I ran each one of the cases until the force plot had become steady.
Seeing that the force results for the Tips Forward vs. Tails Forward cases were very similar, I decided I should also run a ‘Bases Up’ Orientation, even though I STRONGLY advise against this, as UV wrecks the base material of your skis/snowboard.
In addition to the contour plot shown in the images above, you can also use emitters to show streamlines and particle flow, which also give some pretty neat visualizations.
The graph plots show values for the Total Y Force for Tips Foward, Tails Forward, and Bases Up orientations to be 37.7 N, 39.1 N, and 37.1 N, respectively. Using Discovery Live, I was able to quickly run all 3 of these simulations, showing that there is not a major difference in the forces on the ski rack between the three orientations. So, put the skis on the roof in the direction that makes life easiest for you, and keep those bad boys paired to protect your bases from the sun, because splitting them isn’t going to help with aerodynamics anyway!
Next steps would be taking a specific case and running in 2D, then 3D, in ANSYS Fluent.
One of the great new features in ANSYS Mechanical 19.2 is the ability to perform a lattice optimization. Accomplished as an option within Topology Optimization, lattice optimization allows us to generate a lattice structure within our region of interest. It includes varying thickness of the lattice members as part of the optimization.
Lattice structures can be very beneficial because weight can be substantially reduced compared to solid parts made using traditional manufacturing methods. Further, recent advances in additive manufacturing enable the creation of lattice structures in ways that weren’t possible with traditional manufacturing.
Here I’ll explain how to perform a lattice optimization in ANSYS 19.2 step by step.
The procedure starts the same as a normal topology optimization in ANSYS Mechanical, with an initial static structural analysis on our original part or assembly. If you’re not familiar with the process, this earlier PADT Focus blog should be helpful: http://www.padtinc.com/blog/the-focus/topological-optimization-in-ansys-18-1-motorcycle-component-example
For the lattice optimization, I’m starting with a part I created that acts as a corner brace:
At this early point in the simulation, the Project Schematic looks like this:
I used the Multizone mesh method to get a hex mesh on the part:
Simple loads and constraints are recommended especially if you’ll be doing a downstream validation study. That is because the downstream simulation on the resulting lattice geometry will most likely need to operate on the FE entities rather than geometric entities for load and constraint application. The boundary conditions in this simple model consisted of a fixed support on one side of the brace and a force load on the other side:
After solving, I reviewed the displacement as well as the stress results:
Satisfied with the results, the next step is to add a Topology Optimization block in the Project Schematic. The easiest way to do this is to right click on the Solution cell, then select Transfer Data to New > Topology Optimization:
You may need to re-solve the static structural simulation at this point. You’ll know if you have yellow thunderbolts in the Project Schematic instead of green checkmarks for the Static Structural analysis.
At this point, the Project Schematic now looks like this:
The Mechanical window now has the Topology Optimization branch added:
The change to make to enable a lattice optimization is accomplished in the details view of the Optimization Region branch:
We then need to specify some settings for the lattice. The first of these is the Lattice Type. The various types are documented in the ANSYS 19.2 Help. In my example I selected the Crossed option.
The other properties to define are:
Values I used in my example are shown here:
Assuming no other options need to be set, we solve the lattice optimization and review the results. The results are displayed as a contour plot with values between zero and one, with values corresponding to the density settings as specified above.
Note that at this stage we don’t actually visualize the lattice structure – just a contour plot of where the lattice can be in the structure. Where density values are higher than the maximum density specified, the geometry will end up being solid. The lattice structure can exist where the results are between the minimum and maximum density values specified, with a varying thickness of lattice members corresponding to higher and lower densities.
The next step is to bring the lattice density information into SpaceClaim and generate actual lattice geometry. This is done by adding a free standing Geometry block in the Workbench Project Schematic.
The next step is to drag and drop the Results cell from the Topology Optimization block onto the Geometry cell of the new free standing Geometry block:
The Project Schematic will now look like this:
Notice the Results cell in the Topology Optimization branch now has a yellow lightning bolt. The next step is to right click on that Results cell and Update. The Project Schematic will now look like this:
Before we can open SpaceClaim, we next need to right click on the Geometry cell in the downstream Geometry block and Update that as well:
After both Updates, the Project Schematic will now look like this:
The next step is to double click or right click on the now-updated Geometry cell to open SpaceClaim. Note that both the original geometry and a faceted version of the geometry will exist in SpaceClaim:
It may seem counter intuitive, but we actually suppress the faceted geometry and only work with the original, solid geometry for the faceted process. The faceted geometry should be automatically suppressed, as shown by the null symbol, ø, in the SpaceClaim tree. At this point it will be helpful to hide the faceted geometry by unchecking its box in the tree:
Next we’ll utilize some capability in the Facets menu in SpaceClaim to create the lattice geometry, using the lattice distribution calculated by the lattice optimization. Click on the Facets tab, then click on the Shell button:
Set the Infill option to be Basic:
At this point there should be a check box for “Use Density Attributes” below the word Shape. This check box doesn’t always appear. If it’s not there, first try clicking on the actual geometry object in the tree:
In one instance I had to go to %appdata%\Ansys and rename the v192 folder to v192.old to reset Workbench preferences and launch Workbench again. That may have been ‘pilot error’ on my part as I was learning the process.
The next step is to check the Use density attributes box. The Shape dropdown should be set to Lattices. Once the Use density attributes box is checked, we can then one of the predefined lattice shapes, which will be used for downstream simulation and 3D printing. The shape picked needs to match the lattice shape previously picked in the topology optimization.
In my case I selected the Cube Lattice with Side Diagonal Supports, which corresponds to the Crossed selection I made in the upsteam lattice optimization. Note that a planar preview of this is displayed inside the geometry:
The next step is to click the green checkmark to have SpaceClaim create the lattice geometry based on the lattice distribution calculated by the lattice optimization:
When SpaceClaim is done with the lattice geometry generation, you should be able to see a ghosted image showing the lattice structure in the part’s interior:
Note that if you change views, etc., in SpaceClaim, you may then see the exterior surfaces of the part, but rest assured the lattice structure remains in the interior.
Your next step may need to be a validation. To do this, we create a standalone Static Structural analysis block on the Project Schematic:
Next we drag and drop the Geometry cell from the faceted geometry block we just created onto the Geometry cell of the newly created Static Structural block:
We can now open Mechanical for the new Static Structural analysis. Note that the geometry that comes into Mechanical in this manner will have a single face for the exterior, and a single face for the exterior. To verify that the lattice structure is actually in the geometry, I recommend creating a section plane so we can view the interior of the geometry:
To mesh the lattice structure, I’ve found that inserting a Mesh Method and setting it to the Tetrahedrons/Patch Independent option has worked for getting a reasonable mesh. Care must be taken with element sizes or a very large mesh will be created. My example mesh has about 500,000 nodes. This is a section view, showing the mesh of the interior lattice structure (relatively coarse for the example).
For boundary condition application, I used Direct FE loads. I used a lasso pick after aligned the view properly to select the nodes needed for the displacement and then the force loads, and created Named Selections for each of those nodal selections for easy load application.
Here are a couple of results plots showing a section view with the lattice in the interior (deflection followed by max principal stress):
Here is a variant on the lattice specifications, in which the variance in the thickness of the lattice members (a result of the optimization) is more evident:
Clearly, a lot more could be done with the geometry in SpaceClaim before a validation step or 3D printing. However, hopefully this step by step guide is helpful with the basic process for performing a lattice optimization in ANSYS Mechanical and SpaceClaim 19.2.
As it so often does, another blog article idea came from a tech support question that I received the other day. “How do you view edge directions in ANSYS SpaceClaim?”
You can do it in Mechanical, on the Edge Graphics Options Toolbar:
This will turn on arrows so that you can see the edge directions. The directions of the edges or curves affects things like mesh biasing factors and mass flow rate boundary conditions. You need to make sure that all your pipes in a thermal analysis, for instance, are flowing in the same direction.
(I have also had three tech support calls about weird spikes showing up in customers’ geometry. The Display Edge Direction is also how you turn those off.)
In ANSYS SpaceClaim, there is no way to just display the edge directions. The directions are controlled by which point you pick first while sketching, so if you are careful, you can make sure they are all consistent. But that doesn’t help when you read in CAD files. So I thought I would share with you what I found, after a little bit of digging and playing. I discovered that the Move Tool behaves in a very specific way, a way that we can use for our need.
When you pick on the edge of a surface or solid, or even a straight sketched line, the red arrow of the Move Tool will point in the direction of the curve. These directions match what gets shown in Mechanical.
For splines, it’s a little bit different. If you just pick a spline with the Move Tool, the triad will align with the global coordinate system.
To see the spline direction, you first have to hover over the spline, to show the vertices of the spline.
Then you can pick an interior vertex, and the Blue arrow of the Move Tool will follow the spline direction.
This only works at the interior vertices, and not at the ends. At the ends, the Blue tool arrow will always point outward from the spline endpoints, so you won’t really know which is the correct spline direction.
I have also found that this technique does not work on sketched circles or arc because the tool always anchors to the center of the curve, and not to the curve itself. You can, however, use the Repair>Fit Curves tool to convert arcs to splines, using only the Spline option. Then the Move tool will show those directions as described above. For circles, you have to make one more step, and first, use the Split tool to split the circle into two arcs. All that though is, in my opinion, more work than it’s worth.
I hope this helps make your lives just a little easier. Have a great day.
ANSYS HFSS features an integrated “history-based modeler”. This means that an object’s final shape is dependent on each and every operation performed on that object. History-based modelers are a perfect choice for analysis since they naturally support parameterization for design exploration and optimization. However, editing imported solid 3D Mechanical CAD (or MCAD) models can sometimes be challenging with a history-based modeler since there are no imported parameters, the order of operation is important, and operational dependencies can sometimes lead to logic errors. Conversely, direct modelers are not bound by previous operations which can offer more freedom to edit geometry in any order without historic logic errors. This makes direct modelers a popular choice for CAD software but, since dependencies are not maintained, they are not typically the natural choice for parametric analysis. If only there was a way to leverage the best of both worlds… Well, with ANSYS, there is a way.
As discussed in a previous blog post, since the release of ANSYS 18.1, ANSYS SpaceClaim Direct Modeler (SCDM) and the MCAD translator used to import geometry from third-party CAD tools are now packaged together. The post also covered a few simple procedures to import and prepare a solid model for electromagnetic analysis. However, this blog post will demonstrate how to define parameters in SCDM, directly link the model in SCDM to HFSS, and drive a parametric sweep from HFSS. This link unites the geometric flexibility of a direct modeler to the parametric flexibility of a history-based modeler.
You can download a copy of this model here to follow along. If you need access to SCDM, you can contact us at firstname.lastname@example.org. It’s also worth noting that the processes discussed throughout this article work the same for HFSS-IE, Q3D, and Maxwell designs as well.
 To begin, open ANSYS SpaceClaim and select File > Open to import the step file.
 Split the patch antenna and reference plane from the dielectric. Click here for steps to splitting geometry. Notice the objects can be renamed and colors can be changed under the Display tab.
 Click and hold the center mouse button to rotate the model, zoom into the microstrip feed using the mouse scroll, then select the side of the trace.
 Rotate to the other side of the microstrip feed, hold the Ctrl key, and select the other side of the trace. Note the distance between the faces is shown as 3mm in the Status Bar at the bottom of the screen, which is the initial trace width.
 Select Design > Edit > Pull and select No merge under Options – Pull.
 Click the yellow arrow in the model, and drag the side of the trace. Notice how both faces move in or out to change the trace width. After releasing the mouse, a P will appear next to the measurement box. Click this P to create a parameter.
 Select the Groups panel under the Structure tree. Change “Group1” to “traceWidth” and reset the Ruler dimension to 0mm. Then, save the project as UWB_Patch_Antenna_PCB.scdoc and leave SCDM open.
 Open ANSYS Electronics Desktop (AEDT), insert a new HFSS Design, and select the menu item Modeler > SpaceClaim Link > Connect to Active Session… Notice that there is an option to browse and open any SCDM project if the session is not currently active (or open).
 Select the active UWB_Patch_Antenna_PCB session and click Connect.
 The geometry from SCDM is automatically imported into HFSS.
 Double-click the SpaceClaim1 model in the HFSS modeler tree and select the Parameters tab in the pop-up dialogue box. Notice the SCDM parameter can now be controlled within HFSS. Change the Value of traceWidth to SCDM_traceWidth to create a local variable and set SCDM_traceWidth equal to -1mm. Then click OK. Notice a lightning bolt over the SpaceClaim1 model to indicate changes have been made.
 Right-click SpaceClaim1 in the modeler tree and select Send Parameters and Generate.
 Notice how the HFSS geometry reflects the changes.
 Notice how the SCDM also reflects the changes. In practice, it is generally recommended to browse to unopen SCDM projects (rather than connecting to an active session) to avoid accidentally editing the same geometry in two places.
At this point, not only can the geometry in SCDM be controlled by variables in HFSS, but a parametric analysis can now be performed on geometry within a direct modeler. The best of both worlds!
Use the typical steps within HFSS to setup a parametric sweep or optimization. When performing a parametric analysis, the geometry will automatically update the link between HFSS and SCDM, so step  above does not need to be performed manually. Be sure to follow the typical HFSS setup procedures such as assigning materials, defining ports and boundaries, and creating a solution setup before solving.
Here are some additional pro-tips:
We’ve discussed topological optimization in this space before, notably here:
If you’re not familiar with topological or topology optimization, a simple description is that we are using the physics of the problem combined with the finite element computational method to decide what the optimal shape is for a given design space and set of loads and constraints. Typically our goal is to maximize stiffness while reducing weight. We may also be trying to keep maximum stress below a certain value. Frequencies can come into play as well by linking a modal analysis to a topology optimization.
Why is topology optimization important? First, it produces shapes which may be more optimal than we could determine by engineering intuition coupled with trial and error. Second, with the rise of additive manufacturing, it is now much easier and more practical to produce the often complex and organic looking shapes which come out of a topological optimization.
ANSYS, Inc. has really upped the game when it comes to utilizing topology optimization. Starting with version 18.0, topo opt is built in functionality within ANSYS. If you already know ANSYS Mechanical, you already know the tool that’s used. The ANSYS capability uses the proven ANSYS solvers, including HPC capability for efficient solves. Another huge plus is the fact that SpaceClaim is linked right in to the process, allowing us to much more easily make the optimized mesh shape produced by a topological optimization into a more CAD representation set for use in validation simulations, 3D printing, or traditional manufacturing.
The intent of this blog is to show the current process in ANSYS version 18.1 using a simple example of an idealized motorcycle front fork bracket optimization. We don’t claim to be experts on motorcycle design, but we do want to showcase what the technology can do with a simple example.Motorbike Sport blogs can provide you more idea about motorcycle design. We start with a ‘blob’ or envelope for the geometry of our design space, then perform an optimization based on an assumed set of loads the system will experience. Next we convert the optimized mesh information into solid geometry using ANSYS SpaceClaim, and then perform a validation study on the optimized geometry.
Here we show our starting point – an idealized motorcycle fork with a fairly large blob of geometry. The intent is to let ANSYS come up with an optimal shape for the bracket connecting the two sides of the fork.
The first step of the simulation in this case is a traditional Static Structural simulation within ANSYS Workbench. The starting point for the geometry was ANSYS SpaceClaim, but the initial geometry could have come from any geometry source that ANSYS can read in, meaning most CAD systems as well as Parasolid, SAT, and STEP neutral file formats.
A single set of loads can be used, or multiple load cases can be defined. That’s what we did here, to simulate various sets of loads that the fork assembly might experience during optimization. All or a portion of the load cases can be utilized in the topological optimization, and weighting factors can be used on each set of loads if needed.
Here we see the workflow in the ANSYS Workbench Project Schematic:
Block A is the standard static structural analysis on the original, starting geometry. This includes all load cases needed to describe the operating environment. Block B is the actual topological optimization. Block C is a validation study, performed on the optimized geometry. This step is needed to ensure that the optimized shape still meets our design intent.
Within the topology optimization, we set our objective. He we choose minimizing compliance, which is a standard terminology in topology optimization and we can think of it as the inverse which is maximizing stiffness.
In the static structural analysis, 7 load cases were used to describe different loading situations on the motorcycle fork, and here all have been used in the optimization.
Further, we defined a response constraint, which in this example is to reduce mass (actually retain 15% of the mass):
Another quantity that’s often useful to specify is a minimum member constraint. That will keep the topology optimization from making regions that are too small to 3D print or otherwise manufacture. Here we have specified a minimum member size of 0.3 inches:
Since the topological optimization solution uses the same ANSYS solvers for the finite element solution as a normal solution, we can leverage high performance computing (distributed solvers, typically) to speed up the solution process. Multiple iterations are needed to converge on the topology optimization, so realize that the topo opt process is going to be more computationally expensive than a normal solution.
Once the optimization is complete, we can view the shape the topo opt method has obtained:
Notice that only a portion of the original model has been affected. ANSYS allows us to specify which regions of the model are to be considered for optimization, and which are to be excluded.
Now that we have a shape that looks promising, we still need to perform a validation step, in which we rerun our static simulation with the loads and constraints we expect the fork assembly to experience. To do that, we really want a ‘CAD’ model of the optimized shape. The images shown above show the mesh information that results from the topo opt solution. What we need to do next is leverage the ANSYS SpaceClaim geometry tool to create a solid model from the optimized shape.
A simple beauty in the ANSYS process is that with just a couple of clicks we proceed from Block B to Block C in the Workbench project schematic, and can then work with the optimized shape in SpaceClaim.
As you can see in the above image, SpaceClaim automatically has the original geometry as well as the new, optimized shape. We can do as much or as little to the optimized shape as we need, from smoothing and simplification to adding manufacturing features such as holes, bosses, etc. In this case we simply shrink wrapped it as-is.
Continuing with the validation step, the geometry from SpaceClaim automatically opens in the Mechanical window and we can then re-apply the needed loads and constraints and then solve to determine if the optimized shape truly meets our design objectives. If not, we can make some tweaks and run again.
The above image shows a result plot from the validation step. The geometry efficiently comes through SpaceClaim from the optimization step to the validation step. The needed tools are all nicely contained within ANSYS.
Hopefully this has given you an idea of what can be done with topology optimization in ANSYS as well as how it’s done. Again, if you already know ANSYS Mechanical, you already know the bulk of how to do this. If not, then perhaps what you have seen here will spark a craving to learn. We can’t wait to see what you create.
The ANSYS App Store contains all sorts of free and paid apps developed by ANSYS as well as trusted partners. These apps improve workflows and allow users to build in best practices. An app that has been of particular interest to me is Workbench Poly Meshing for Fluent.
This app enables the power and capacity of Fluent Meshing, most notably the polyhedral meshing feature, with the ease of use of the ANSYS Workbench Meshing environment. In order to show the functionality of this app, I will demonstrate with the generation of a polyhedral mesh on a sample geometry from the Fluent Meshing tutorials.
To start out, I have imported a .igs file of an exhaust manifold into ANSYS SpaceClaim Direct Modeler, which has powerful repair and prepare tools that will come in handy. I notice that the geometry is comprised of 250 surfaces, which I need to fix in order to create a solid body. By navigating into the ‘Repair’ tab and selecting the ‘Stitch’ operation, SpaceClaim notes there are two stitchable edges in my geometry. I select the green check mark to perform this operation and am greeted with a solid geometry. I complete my tasks in SpaceClaim by extracting the fluid volume using the ‘Volume Extract’ tool in the ‘Prepare’ tab.
I setup my workflow in ANSYS workbench with my added ‘Fluent Meshing’ ACT module between the ‘Mesh’ module and ‘Fluent’ module. I can then proceed to create my desired surface mesh in ANSYS meshing and setup a few required inputs for Fluent Meshing.
Once this process has been completed, I can update my ‘Fluent Meshing’ cell and open the ‘Fluent’ setup cell to display my polyhedral mesh!
IMPORTANT NOTE: all named selections must be lowercase with no spaces, and the file path(s) cannot contain any spaces.
Occasionally when solid geometry is imported from CAD into ANSYS SpaceClaim the geometry will come in as solids, but when a mesh is generated on the solids the mesh will appear to “leak” into the surrounding space. Below is an assembly that was imported from CAD into SpaceClaim. In the SpaceClaim Structure Window all of the parts can be seen to be solid components.
When the mesh is generated in ANSYS Mechanical it appears like the assembly has been successfully meshed.
However, when you look at the mesh a little closer, the mesh can be missing from some of the surfaces and not displayed correctly on others.
Additionally, if you create a cross-section through the mesh, the mesh on some of the parts will “leak” outside of the part boundaries and will look like the image below.
Based on the mesh color, the mesh of the part in the center of the assembly has grown outside of the surfaces of the part.
To repair the part you need to go back to SpaceClaim and rebuild it. First you need to hide the rest of the parts.
Next, create a sketch plane that passes through the problem part.
In the sketch mode create a rectangle that surrounds the part. When you return to 3D mode in SpaceClaim, that rectangle will become a surface that passes through the part.
Now use the Pull tool in SpaceClaim to turn that surface into a part that completely surrounds the part to be repaired, making sure to turn on the “No Merge” option for the pull before you begin.
After you have pulled the surface into a solid, it should like the image below where the original part is completely buried inside the new part.
Now you will use the Combine tool to divide the box with the original part. Select Combine from the Tool Bar, then select the box that you created in the previous step. The cutter will be activated and you will move the cursor around until the original part is highlighted inside the box. Select it with the left mouse button. The Combine tool will then give you the option to select the part of the box that you want to remove. Select the part that surrounds the original part. After it is finished, close the combine tool and the Structure Tree and 3D window will now look like the following:
Now move the new solid that was created with the Combine tool into the location of the original part and turn off the original one and re-activate the other parts of the assembly. The assembly and Structure Tree should now look like the pictures below.
Now save the project, re-open the meshing tool, and re-generate the mesh. The mesh should now be correct and not “leaking” beyond the part boundaries.
There were some changes in ANSYS SpaceClaim to the very useful tool that lets you create a surface patch on scan or STL data at 18.0. In this video we show how to create corner points for a surface patch boundary and how to get an accurate measurement of how far the surface you create deviates from the STL or scan data underneath.
After playing with that block it seems like it may be time to try a more complex geometry. For business banking, I’ve got this key fob that generates a number every thirty seconds that I use for security when I log in. Might as well sort of model that.
So the first thing I do is start up a new model and orient myself on to the sketch plane:
Then I use the line and arc tools to create the basic shape. Play around a bit. I found that a lot of things I had to constrain in other packages are just assumed when you define the geometry. A nice thing is that as you create geometry, it locks to the grid and to other geometry.
I dragged around and typed in values for dimensions to get the shape I wanted. As I was doing it I realized I was in metric. I’m old, I don’t do metric. So I went in to File and selected SpaceClaim options from the bottom of the window. I used the Units screen to set things to Imperial.
This is the shape I ended up with:
I took this and pulled it up and added a couple of radii:
But if I look at the real object, the flat end needs to be round. In another tool, I’d go back to the sketch, modify that line to be an arc, and regen. Well in SpaceClaim you don’t have the sketch, it is gone. Ahhh. Panic. I’ve been doing it that way for 25 some years. OK. Deep breath, just sketch the geometry I need. Click on the three point arc tool, drag over the surface, then click on the first corner, the second, and a third point to define the arc:
Then us pull to drag it down, using the Up to icon to lock it to the bottom of the object.
Then I clicked on the edges and pulled some rounds on there:
OK, so the next step in SolidEdge would be to do a thin wall. I don’t see a thin wall right off the top, but shell looks like what I want, under the Create group on the Design tab. So I spinned my model around, clicked on the bottom surface I want to have open and I have a shell. A thickness of 0.035″ looks good:
My next feature will be the cutout for the view window. What I have not figured out yet is how to lock an object to be symmetrical. Here is why. I sketch my cutout as such, not really paying attention to where it is located. Now I want to move it so that it is centred on the circle.
Instead of specifying constraints, you move the rectangle to be centered. To do that I drag to select the rectangle then click Move. By default it puts the nice Move tool in the middle of the geometry. If I drag on the X direction (Red) you can see it shows the distance from my start.
So I have a couple of options, to center it. The easiest is to use Up To and click the X axis for the model and it will snap right there. The key thing I learned was I had to select the red move arrow or it would also center horizontally where I clicked.
If I want to specify how far away the edge is from the center of the circle, the way I did it is kind of cool. I selected my rectangle, then clicked move. Then I clicked on the yellow move ball followed by a click on the left line, this snapped the move tool to that line. Next I clicked the little dimension Icon to get a ruller, and a small yellow ball showed up. I clicked on this and dragged it to the center of my circle, now I had a dimension from the circle specified that I could type in.
After playing around a bit, if found a second, maybe more general way to do this. I clicked on the line I want to position. One of the icons over on the left of my screen is the Move Dimension Base Point icon. If you click on that you get another one of those small yellow balls you can move. I dragged it over to the center of the circle and clicked. then I can specify the distance as 0.75″
I’ve got the shape I want, so I pull, using the minus icon to subtract, and I get my cutout:
If you look closely,you will notice I put rounds on the corners of the cutout as well, I used Pull again.
The last thing I want to do is create the cutout for where the bank logo goes. It is a concentric circle with an arc on the right side. Saddly, this is the most complex thing I’ve ever sketched in SpaceClaim so I was a bit afraid. It was actually easy. I made a circle, clicking on the center of the outside arc to make them concentric. The diameter was 1″. Then I made another circle of 2″ centered on the right. To get the shape I wanted, I used the Trim Away command and clicked on the curves I don’t want. The final image is my cutout.
Now I can do the same thing, subtract it out, put in some rounds, and whalla:
Oh, and I used the built in rendering tool to quickly make this image. I’ll have to dedicate a whole posting to that.
But now that I have my part, it is time to play with move in 3D.
Tyler, who is one of our in-house SpaceClaim experts (and younger) pointed out that I need to start thinking about editing the 3D geometry instead of being obsessed with controlling my sketches. So here goes.
If I wanted to change the size of the rectangular cutout in a traditional CAD tool, I’d go edit the sketch. There is no sketch to edit! Fear. Unknown. Change.
So the first thing I’ll do is just move it around. Grab one of the faces and see happens.
It moves back and forth, pretty simple. The same tools for specifying the start and stop points are available. Now, if I ctrl-click on all four surfaces the whole thing moves. That is pretty cool.
Note: I’m using the undo all the time to go back to my un-moved geometry.
Another Note: As you select faces, you have to spin the model around a lot. I use the middle mouse button to do this rather than clicking on the spin Icon and then having to unclick it.
That is enough for this post. More soon.
As I explored ANSYS SpaceClaim in my first try, it became obvious that a lot of capabilities that are in multiple operations in most CAD systems, are all combined in Pull for SpaceClaim. In this posting I feel like it would be a really good idea for me to really understand all the things Pull can do.
Not very exciting or adventurous. But there is so much in this operation that I feel like I will miss something critical if I don’t read up first. It states:
“Use the Pull tool to offset, extrude, revolve, sweep, and draft faces; use it to round, chamfer, extrude, copy, or pivot edges. You can also drag a point with the Pull tool to draw a line on a sketch plane.”
Let’s think about that for a second. What it is basically saying is if I pull on an object of a given dimension, it creates an object that is one higher dimension. Point pulls to a curve, a curve pulls to a face, and a face pulls to a solid. Kind of cool. The big surprise for me is that there is no round or fillet command. To make a round you pull on an edge. This is change.
I started by reading my block with a hole back in.
This fillet pull thing scares me so I thought I’d confront it first. So selecte Pull, and selected an edge:
Then I dragged it away from the block. Nothing. You can’t create a surface that way. Then I dragged in towards the center. A round was created.
If anything, too simple. Back in my day, adding a round to an edge took skill and experience!
So next I think I want to try and change the size of something. Maybe the diameter of the hole. So I select the cylinder’s face. Is shows the current radius. I could just change that value:
Instead I drag, and while I do that I noticed that there are two numbers, the current radius and the change to the radius! Kind of cool. No, really useful.
You use tab to go between them. So I hit tab once, typed 3 then tab again (or return) and I get a 8 mm diameter. I like the visual feedback as well as the ability to enter a specific change number.
Next thing that I felt like doing was rounding a corner. Put a 5mm round on the corner facing out:
So I grabbed the point and dragged, and got a line.
Remember, it only goes up one entity type – point to curve. Not point to surface. So I ctrl-clicked (that is how you select multiple entities) on the three curves that intersect at the corner:
Then I dragged and got my round.
This are all sort of dragging straight. After looking at the manual text it seems I can revolve and sweep as well with the Pull operation. Cool. But what do I revolve or sweep around and along? Looking at the manual (and it turns out the prompt on the screen) I use Alt-Clicking to define these control curves. Let’s try it out by revolving something about that line I mistakenly made.
I click on one of the curves on the round. then Alt-Click the line – It turns blue. So there is a nice visual clue that it is different than the source curve. Now I’ve also got spinny icons around the curve rather than pull icons.
So I drag and… funky revolved surface shows up. I had to spin the model to see it clearly:
Let me stop and share something special about this. In most other CAD tools, this would have involved multiple clicks, maybe even multiple windows. In SpaceClaim, it was Click, Alt-Click, Drag. Nice.
Using the Pop=up Icons
As you play with the model you may start seeing some popup icons near the mouse when you select geometry while using pull. The compound round on the block is complicated, so I spun it around and grabbed just one edge and pulled it in to be a round. Then I clicked on it and got this:
Not only can I put a value in there, I can drop ones I use a lot. I can also change my round to a chamfer, or I can change it to a variable radius. This is worth noting. In most other CAD tools you pick what type of thing you want to do to the edge. Here we start by dragging a round, then specify if it is a chamfer or a variable.
The variable radius is worth digging more in to. I clicked on it and it was not intuitive as to what I should do. Let’s try help. Search on Variable Radius… duh. Click on the arrow that shows up and drag that. There are three arrows. The one in the middle scales both ends the same, the one on either end, well it sets the radius for either end.
Clicking on a control point and hitting delete, gets rid of them.
That’s just one icon that pops up. Playing some more it seems the other icons control how it handles corners and multiple fillets merging… something to look at as I do more complex parts.
The other popup I want to look at is the Up To one. It looks like an arrow on a surface. In other tools I extrude, cut, revolve all the time to some other piece of geometry. This is the way to do it in Space Claim. Let’s say I want to pull a feature to the middle of my hole. First I sketch the outline on a face:
That is enough for pulling and for today. In the next session it may be time to explore the Move command.
This post is a table of contents to a series about ANSYS SpaceClaim. After over 31 years of CAD use, it has become difficult for me to learn new tools. In this series I will share my experience as I explore and learn how to use this fantastic tool.
Thirty-one. That is the number of years that I have been using CAD software. CADAM was the tool, 1985 was the year. As some of our engineers like to point out, they were not even born then.
Twenty-one. that is the number of years that I have been using SolidEdge. This classifies me as an old dog, a very old dog. As PADT has grown the amount of CAD I do has gone way down, but every once in a while I need to get in there and make some geometry happen. I’m usually in a hurry so I just pop in to SolidEdge and without really thinking, I get things done.
Then ANSYS, Inc. had to go and buy SpaceClaim. It rocks. It is not just another solid modeler, it is a better way to create, repair, and modify CAD. I watch our engineers and customers do some amazing things with it. I’m still faster in SolidEdge because I have more years of practice than they have been adults. But this voice in my head has been whispering “think how fast you would be in SpaceClaim if you took the time to learn it.” Then that other voice (I have several) would say “you’re too old to learn something new, stick with what you know. You might break your hip”
I had used SpaceClaim a bit when they created a version that worked with ANSYS Mechanical four or five years ago, but nothing serious. Last month I attended some webinars on R17 and saw how great the tool is, and had to accept that it was time. That other voice be damned – this old dog needs to get comfortable and learn this tool. And while I’m at it, it seemed like a good idea to bring some others along with me.
These posts will be a tutorial for others who want to learn SpaceClaim. Unlike those older tools, it does not require five days of structured training with workshops. The program comes with teaching material and tutorials. The goal is to guide the reader through the process, pointing out things I learned along the way, as I learn them.
A link to the table of contents is here.
The product I’m learning is ANSYS SpaceClaim Direct Modeler, a version of SpaceClaim that is built into the ANSYS simulation product suite. There is a stand alone SpaceClaim product but since most of our readers are ANSYS users, I’m going to stick with this version of the tool.
This is what you see when you start it up:
I’ve been using the same basic layout for 20 years, so this is a bit daunting for me. I like to start on a new program by getting to know what different areas of the user interface do. The “Welcome to ANSYS SCDM” kind of anticipates that and gives me some options.
Under “Getting Started” you will see a Quick Reference Card, Introduction, and Tutorials. Open up the Quick Reference and print it out. Don’t bother with it right now, but it will come in handy, especially if you are not going to use SpaceClaim every day.
The Introduction button is a video that gets you oriented with the GUI. Just what we need. It is a lot of information presented fast, so you are not going to learn everything the first viewing, but it will get you familiar with things.
Here I am watching the video. Notice how attentive I am.
Once that is done you should sort of know the basic lay of the land. Kind of like walking into a room and looking around. You know where the couch is, the window, and the shelf on one wall. Now it is time to explore the room.
It is kind of old school, but I like user guides. You can open the SpaceClaim User Guide from the Help line in the “Welcome” window. I leave it open and use it as a reference.
The best place to learn where things are in the interface is to look at the interface section in the manual. It has this great graphic:
The top bit is pretty standard, MS office like. You have your application menu, quick access toolbar, and Ribbon Bar. The Ribbon Bar is where all the operations sit. We used to call these commands but in an object oriented world, they are more properly referred to as operations – do something to objects, operate on them. I’ll come back and explore those later. Over on the left there are panels, the thing we need to explore first because they are a view into our model just like the graphics window.
The Structure Panel is key. This is where your model is shown in tree form, just like in most ANSYS products. In SpaceClaim your model is collection of objects, and they are shown in the tree in the order you added them. You can turn visibility on and off, select objects, and act on objects (using the right mouse button) using the tree. At this point I just had one solid, so pretty boring. I’m sure it will do more later.
Take a look at the bottom of the Structure Panel and you will find some tabs. These give access to Layers, Selection, Groups, and Views. All handy ways to organize and interact with your model. I felt like I needed to come back to these later when I had something to interact with.
TIP: If you are like me, you probably tried to drag these panels around and hosed up your interface. Go to File > SpaceClaim Options (button at the bottom) > Appearance and click the “Reset Docking Layout” button in the upper right of the window. Back to normal.
The options panel changes dynamically as you choose things from the ribbon. If you click on the Design > Line you get this:
And if you click on Pull you get this:
Keeps the clutter down and makes the commands much more capable.
Below that is the Properties Panel. If the Options panel is how you control an operation, then the Properties panel is how you view and control an object in your model. No point in exploring that till we have objects to play with. It does have an appearance tab as well, and this controls your graphics window.
At the bottom is the Status Bar. Now I’m a big believer in status bars, and SpaceClaim uses theirs well. It tells you what is going on and/or what to do next. It also has info on what you have selected and short cut icons for selection and graphics tools. Force yourself to read and use the status bar, big time saver.
The last area of the interface is the graphics window. It of course shows you your geometry, your model. In addition there are floating tools that show up in the graphics window based upon what you are doing. Grrr. #olddogproblem_1. I’m not a fan of these, cluttering up my graphics. But almost all modern interfaces work this way now and I will have to overcome my anger and learn to deal.
For most of the 30+ years that I’ve been doing this CAD thing, I’ve always started with the same object: A block with a hole in it. So that is what we will do next. I have to admit I’m a little nervous.
I’m nervous because I’m a history based guy. If you have used most CAD tools like SolidWorks or ANSYS DesignModeler you know what history based modeling is like. You make a sketch then you add or subtract material and it keeps track of your operations. SpaceClaim is not history based. You operate on objects and it doesn’t track the steps, it just modifies your objects. SolidEdge has done this for over ten years, but I never got up the nerve to learn how to use it. So here goes, new territory.
Things start the same way. But instead of a sketch you make some curves. The screen looks like this when you start:
The default plane is good enough, so I’ll make my curves on that. Under Design>Sketch click on the Rectangle icon then move your mouse on to the grid. You will notice it snaps to the grid. Click in the Upper Left and the Lower Right to make a rectangle then enter 25mm in to each text box, making a 25 x 25 square:
Next we want to make our block. In most tools you would find an extrude operation. But in SpaceClaim they have combined the huge multitude of operations into a few operation types, and then use context or options to give you the functionality you want. That is why the next thing we want to do is click on Pull on the Edit group.
But first, notice something important. If you look at the model tree you will notice that you have only one object in your design, Curves. When you click Pull it gets out of sketch mode and into 3D mode. It also automatically turns your curves into a surface. Look at the tree again.
This is typical of SpaceClaim and why it can be so efficient. It knows what you need to do and does it for you.
Move you mouse over your newly created surface and notice that it will show arrows. Move around and put it over a line, it shows what object will be selected if you click. Go to the inside of your surface and click. It selects the surface and shows you some options right there.
Drag your mouse over the popup menu and you can see that you can set options like add material, subtract material, turn off merging (it will make a separate solid instead of combining with any existing ones), pull both directions, get a ruler, or specify that you are going to pull up to something. For now, we are just going to take the default and pull up.
As you do this the program tells you how far you are pulling. You can type in a value if you want. I decided to be boring and I put in 25 mm. Geometry has been created, no one has been hurt, and I have not lost feeling in any limbs. Yay.
On the status bar, click on the little menu next to the magnifying glass and choose Zoom Extents. That centers the block. Whew. That makes me feel better.
Now for the hole. It is the same process except simpler than in most tools. Click on the circle tool in Sketch. The grid comes back and you can use that to sketch, or you can just click on the top of the block. Let’s do that. The grid snaps up there. To make the circle click in the middle of the grid and drag it out. Put 10 in for the diameter. A circle is born.
Now choose Pull from the Edit section. There is only a Solid now?
SpaceClaim went ahead and split that top surface into two surfaces. Saving a step again.
Click on the circle surface and drag it up and down. If you go up, it adds a cylinder, if you go down, it automatically subtracts. Go ahead and pull it down and through the block and let go. Done. Standard first part created. Use the File>Save command to save your awesome geometry.
That is it for the getting started part. In the next post we will use this geometry to explore SpaceClaim more, now that we have an object to work on. As you were building this you probably saw lots of options and input and maybe even played with some of it. This is just a first look at the power inside SpaceClaim.
Click here for Post 2 where the Pull command is explored.