Quick Tip: Concatenating Text Files Using ANSYS Mechanical APDL

So you have text output from some ANSYS analysis and you wish you could just do this:

cat lift.txt  cop.txt drag.txt >> results.txt

and you are writing an ANSYS macro and want it to run on all platforms.  The following macro will use APDL commands to join the files together. 

macro1.mac

/inquire,linesin1,lines,lift,txt

*sread,str1array,lift,txt,,80,,linesin1

/inquire,linesin2,lines,cop,txt

*sread,str2array,cop,txt,,80,,linesin2

/inquire,linesin3,lines,drag,txt

*sread,str3array,drag,txt,,80,,linesin3

*cfopen,results,txt

*vlen,linesin1

*vwrite,str1array(1)

%80S

*vlen,linesin2

*vwrite,str2array(1)

%80S

*vlen,linesin3

*vwrite,str3array(1)

%80S

*cfclose

Bonus: If you want to strip some lines off of the top or read less than all the lines, you can pass additional arguments to *sread:

/inquire,linesin1,lines,lift,txt

Lines_skip=5

Lines_read=linesin1-lines_skip

*sread,str1array,lift,txt,,80,lines_skip,lines_read

 

Seminar Info: Designing and Simulating Products for 3D Printing

Note: We have scheduled an encore Lunch & Learn and companion Webinar for March 23, 2015.  Please register here to attend in person at CEI in Phoenix or here to attend via the web.

ds43dp-1People are interested in how to better do design and simulation for products they manufacture using 3D Printing.  When the AZ Tech council let us know they had a cancelation for their monthly manufacturing Lunch and Learn, we figured why not do something on this topic, a few people might show up. We had over 105 people register, so we had to close registration. In the end around 95 total people made it to the seminar, which is more than expected so we had to add chairs. Who would have thought that many people would come for such a nerdy topic?.

For an hour and fifteen minutes they sat and listned to us talk about the ins and outs of using this growing technology to make end use parts.  Here is a copy of the PowerPoint as a PDF.

We did add one bullet item in the design suggestions area based on a question. Someone pointed out that the machine instructions, what the AM machine uses to make the parts, should be a controlled document. They are exactly right and that is a very important process that needs to be put in place to get traceability and repeatability.  

Here are some useful links:

As always, do not hesitate to contact us for more information or with any questions.

If you missed this presentation, don't worry, we are looking to schedule a live/web version of this talk with some enhancements sometime in March.  Watch the usual channels for time, place, and registration information. We will also be publishing detailed blog posts on many of the topics covered today, diving deeper into areas of interest.

Thank you to the AZ Tech Council, ASU SkySong, and everyone that attended for making this our best attended non-web seminar ever.

Design and Simulation for 3D Printing Full House

The Full Power of SpaceClaim Engineer – Now Available from PADT

SpaceClaim-1We have been using SpaceClaim with ANSYS Workbench for about four years now, and we always liked it. Then it came as part of the Geomagic Spark tool and we got more excited.  This was a powerful geometry creation, editing, and reapir tool that was saving us time all across PADT.  The, when ANSYS, Inc. purchased the company SpaceClaim we got realy excited.  So excited that we decided to become a reseller of the full product, and not just the ANSYS or Geomagic tools.  The addition of a module for working with STL files sealed the deal and as of the begining of the year we are offering all flavors of SpaceClaim to our customers.

The official press release can be found here. You can learn a lot about the product by visiting the web page.

To get started learning about why we love this program so much, check out this video showing the new features in the latest version:

Then go visit their YouTube channel and watch videos that may be of special interest to you.

Or, contact us here at PADT and we would be happy to share with your our enthusiasm for this tool.

SpaceClaim-Model1b

 

Deflategate Update: ANSYS Simulation Shows it Really Does not Make a Difference.

There is still more debate going on about the deflated footballs that the New England Patriots used in their playoff game. "Who Deflated Them? When? Were they acting on orders?"  But no one is asking if it makes a real difference.

Enter ANSYS simulation software. Using the newest ANSYS product, ANSYS AIM, the engineers at ANSYS, Inc. were able to simulate the effect of lower pressure on grip. It turns out that the the difference in pressure only made a 5mm difference in grip. No big deal.  

Being a Multiphysics tool they were able to quickly also run a flow analysis and see what impact drag from "wobble" had on a pass.  A 10% off axis wobble resulted in 20% more drag, that is a few yards on a long pass.  Their conclusion, throwing a tight spiral is more important than the pressure of the ball.

Check out the full article on the ANSYS blog: 

http://www.ansys-blog.com/superbowl-deflategate-scandal-debunked-using-engineering-simulation/#more-11576

Here is the video as well:

3D Printing to Combat Deflategate

3d-printed-footballIn honor of the big game this weekend the folks at Stratasys scored big time with a 3D printed footballStratasys has had a history of using 3D printing to improve on a variety of sports; however this time they out did themselves by possibly solving the infamous issue of deflategate. Since the Ideal Gas Law doesn't exactly explain it, maybe 3D printing could help prevent it from interfering in the big game until an answer is found. I’m not sure the NFL will be too keen on using these balls but it’s a thought

super-bowl-3d-printed-football

The football was created on the Objet500 Connex3 Color Multi-Material 3D Production System and was printed in three materials.  VeroMagenta and VeroYellow was used for the bulk of the design however they were also able to replicate the true texture and feel of a real football using the rubber-like TangoPlus material and all in one print job.  It is heavier than a game ball but can still be tossed around.  Of course they wouldn’t print a football and not test it.  Check out their video below. 

Bonus Link – Here is a fun Brady Deflategate Inaction Figure from Shapeways. 

Donny Don’t – Remote Objects

Nothing like a good ‘ol fashion Simpson’s reference.  I’m trying to start a new series of articles that address common mistakes and things to avoid, and what better reference than when Bart ‘joined’ the Junior Campers and found out he might get a knife out of the deal. 

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For this first article, let’s talk about remote objects (force, displacement, points, joints).  First, remote objects are awesome.  Want to add a rotational DOF to your solid-object model?  Remote Displacement.  Want to apply a load and don’t want to worry about force/moment balance?  Remote Force.  Want to apply a load but also constrain a surface?  Remote Point.  Take two points and define a open/locked degrees of freedom and you have a kinematic joint.

The thing to watch out for is how you define these remote points.  ANSYS Mechanical does an amazing job at making a pretty tedious process easy (create pilot node, create constraint-type contact, specify DOFs to include, specify formulation).  In Mechanical, all you need to do is highlight some geometry, right mouse click, and insert the appropriate object (remote point, remote force, etc).  No need to keep track of real constant sets, element tshape’s…easy.  Almost too easy if you ask me.

Once you start creating multiple remote objects, you may see the following:

message1

If you dig into the solver output file you may see this:

image

The complaint is that we have multiple overlapping constraint sets.  Let’s take a step back and see the model I’ve setup:

image

I have a cylinder, attached to a body-to-ground spring on one face, a translational joint applied on the OD, and a remote force and moment applied on the opposite end.  If I follow the instructions shown from the ANSYS Workbench message about graphically displaying FE Connections (select the ‘Solution Information’ item, click the graphics tab):

image

We can see that any type of constraint equation is shown in red.  The issue here is that the nodes on the OD edge on the top and bottom of my cylinder belong to multiple constraint equation sets.  On the bottom my my cylinder those nodes are being constrained to the spring end AND the cylindrical joint.  On the top the nodes on the edge are being constrained to the joint AND remote force.  When you hit solve, ANSYS needs to figure out how to resolve the conflicting constraint sets (a node cannot be a slave term for two different constraint sets).  I don’t know exactly how the solver manages this, but I like to imagine it’s like two people fighting over who gets to keep a dog…and they place the dog in-between them and call for it, and whoever the dog goes to gets to keep it. 

Now for this example, the solver is capable of handling the over-constraint because overall…the model is properly constrained.  The spring can loose some of the edge nodes and still properly connect to the cylinder.  Same goes for the other remote objects (translation joint and remote force/moment).  If we had more objects defined and more overlaps, that’s a different story.  You can introduce a pretty lengthy lag, or outright solver failure, if there are a lot of overconstraint terms in the model. 

So now the question becomes, how do I fix this.  The easiest way is to not fix this and ignore the warning.  If our part behaves properly, we get the reaction forces we’d expect, then odds are the overconstraint terms that are automatically corrected are fine.  If we actually wanted to remove that warning, we would need to make sure we scope remote objects that do not touch other remote objects.  We can do this by going into DesignModeler or SpaceClaim and imprinting the surfaces. 

image

In DM, I just extruded the edges with the operation set to imprint face.  In SpaceClaim you would just need to use the ‘copy edge’ option on the pull command:

image

Now this will modify the topology and will ensure we have a separation of nodes for all of our remote objects:

image

When we solve…no warning message about MPC conflicts:

image

And when we look at the FE connectivity, there are no nodes shared by multiple remote objects:

image 

The last thing I’d like to point out is the application of a force and moment on a remote point:

image

Whenever you have two remote objects operating on the same surface (e.g. a moment and force, force and displacement, etc), you should really be using a remote point.  If I were to create two remote objects:

image

I now come right back to my original problem of conflicting constraints.  These two objects share the exact same nodal set but are creating two independent remote points.  If you want to do this, right-mouse-click on one of your remote objects and select ‘promote to remote point’:

image

Then modify the other remote objects to use that remote point.  No more conflict. 

Very last point…in R16 it will now tell you when you have ‘duplicate’ remote objects  (like the remote force + displacement shown above). 

image

Hope this helps! 

3D Printing Saves Money at Hill Air Force Base in Utah

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An F-16 wing attachment, molded from plastic in a 3-D printer, was used as a prototype before being machined in metal. The 309th Maintenance Support Group at Hill Air Force Base, Utah, is using Rapid Prototyping, also known as 3-D printing, to create prototype parts. (U.S. Air Force photo/Bill Orndorff)

We had the pleasure of working with Hill Air Force Base in Utah to implement a Rapid Prototyping or 3D printing solution using Stratasys’ Fortus 900.  Since implementing the machine, they have seen some enormous money and time cost savings without compromising quality.

The printer at Hill AFB is used for a variety of applications from form and fit testing of new designs, tooling, and fixtures to training aids and end use parts.  They have received lots of positive feedback from their customers because they are able to adapt and quickly make changes to meet their specifications.  

The Fortus 900 is the largest FDM printer offered by Stratasys and is about the size of a mini-van.  Material options include a variety of thermoplastic materials with capabilities ranging from high heat tolerances and impact resistance to chemical resistance.

For more details on the success at Hill Air Force Base, check out an article they recently published here.

Thermal Submodeling in ANSYS Workbench Mechanical 15.0

thermal-submodeling-18
If you've been following The Focus for a long time, you may recall my prior article about submodeling using ANSYS Mechanical APDL, which was a 'sub' model of a submarine.  The article, from 2006, begins on page 2 at this link:

Also, Eric Miller here at PADT wrote a Focus blog entry on the new-at-14.5 submodeling capability in ANSYS Workbench Mechanical.

Since both of those articles were about structural submodeling, I decided it was time we published a blog entry on how to perform submodeling in ANSYS Mechanical for thermal simulations.

Submodeling is a technique whereby we can obtain more accurate results in a small, detailed portion of a large model without having to build an incredibly refined and detailed finite element model of our complete system.  In short, we map boundary conditions onto a 'chunk' of interest that is a subset of our full model so that we can solve that 'chunk' in more detail.  Typically we mesh the 'chunk' with a much finer mesh than was used in the original model, and sometimes we add more detail such as geometric features that didn't exist in the original model like fillets.

The ANSYS Workbench Project Schematic for a thermal solution involving submodeling looks like this:

thermal-submodeling-1

Figure 1 – Thermal Submodeling Project Schematic

Note that in the project schematic, the links are automatically established when we setup the submodel after completing the analysis on the coarse model as we shall see below.

First, here is the geometry of the coarse model.  It's a simple set of cooling fins.  In this idealized model, no fillets have been modeled between the fins and the block.

thermal-submodeling-2

Figure 2 – Coarse Model Geometry, Idealized without Fillets

The boundary conditions consisted of a heat flux due to a  thermal source on the base face and convection to ambient air on the cooling fin surfaces.  The heat flux was setup to vary over the course of 3 load steps as follows:

Load Step        Heat Flux (BTU/s*in^2)

            1                      0.2

            2                      0.5

            3                      0.005

Thus, the maximum heat going into the system occurs in load step 2, corresponding to 'time' 2.0 in this steady state analysis.

thermal-submodeling-3

Figure 3 – Coarse Model Boundary Conditions – Heat Flux and Convection

The coarse model is meshed with relatively large elements in this case.  The mesh refinement for a production model should be sufficient to adequately capture the fields of interest in the locations of interest.  After solving, the temperature results show a max temperature at the base where the heat flux is applied, transitioning to the minimum temperature on the cooling fins where convection is removing heat.

thermal-submodeling-4

Figure 4 – Coarse Model Mesh and Temperature Results for Load Step 2

Our task now is to calculate the temperature in one of these fins with more accuracy.  We will use a finer mesh and also add fillets between the fin and base.  For this example, I isolated one fin in ANSYS DesignModeler, did some slicing, and added a fillet on either side of the base of the fin of interest.

thermal-submodeling-5

Figure 5 – Fine Model (Submodel) Isolated Fin Geometry and Mesh, Including Fillets at Base

 

ANSYS requires that the submodel lie in the exact geometric position as it would in the coarse model, so it's a good idea to overlay our fine model geometry onto the coarse model to verify the positioning.

thermal-submodeling-6

Figure 6 – Submodel and Coarse Model Overlaid

thermal-submodeling-7

Figure 7 – Submodel and Coarse Model Overlaid, Showing Addition of Fillet

The next step is to insert the submodel geometry as a stand-alone geometry block in the Project Schematic which already contains the coarse model, as shown in figure 8.  A new Steady-State Thermal analysis is then dragged and dropped onto the geometry block containing the submodel geometry.

thermal-submodeling-8

Figure 8 – Submodel Geometry Added to Project Schematic, New Steady-State Thermal System Dragged and Dropped onto Submodel Geometry

 

Next, we drag and drop the Engineering Data cell from the coarse model to the Engineering Data cell in the submodel block.  This will establish a link so that the material properties will be shared.

thermal-submodeling-9

Figure 9 – Drag and Drop Engineering Data from Coarse Model to Submodel

The final needed link is established by dragging and dropping the Solution cell from the coarse model onto the Setup cell in the submodel.  This step causes ANSYS to recognize that we are performing submodeling, and in fact this will cause a Submodeling branch to appear in the outline tree in the Mechanical window for the submodel.

thermal-submodeling-10

Figure 10 – Solution Cell Dragged and Dropped from Coarse Model to Submodel Setup Cell

After opening the Mechanical editor for the submodel block, we can see that the Submodeling branch has automatically been added to the tree.

thermal-submodeling-11

Figure 11 – Submodeling Branch Automatically Added to Outline Tree

After meshing the submodel I specified that all three load steps should have their temperature data mapped to the submodel from the coarse model.  This was done in the Details view for the Imported Temperature branch, by setting Source Time to All.

thermal-submodeling-12

Figure 12 – Set Imported Temperature Source Time to All to Ensure All Loads Steps Are Mapped

Next I selected the four faces that make up the cut boundaries in the submodel and applied those to the geometry selection for Imported Temperature.

thermal-submodeling-13

Figure 13 – Cut Boundary Faces Selected for Imported Temperature

 

As mentioned above, the Imported Temperature details were set to read in all load steps by setting Source Time to All.  The Imported Temperature branch can now be right-clicked and the resulting imported temperatures viewed.  I also inserted a Validation branch which we will look at after solving.

thermal-submodeling-14

Figure 14 – Setting Source Time to All, Viewing Imported Temperature on Submodel

Any other loads that need to be applied to the submodel are added as well.  For this model, it's convection on the large faces of the fin that are exposed to ambient air.

thermal-submodeling-15

Figure 15 – Submodel Convection Load on Fin Exposed Faces

Since there are three load steps in the coarse model and we told ANSYS to map results from all time points, I set the number of steps to three in Analysis Settings, then solved the submodel.  Results are available for all three load steps.

thermal-submodeling-16

Figure 16 – Submodel Temperature Results for Step 2 (Highest Heat Flux Value in Coarse Model)

Regarding the Validation item under the Imported Temperature branch, this is probably best added after the solution is done.  In my case I had to clear it and recalculate it.  Validation can display either an absolute or relative (percent difference) plot on the nodes at which loads were imported.  Figure 17 shows the relative difference plot, which maxes out at about 6%.  The validation information as well as mapping techniques are described in the ANSYS Help.

thermal-submodeling-17

Figure 17 – Submodel Imported Temperature Validation Plot – Percent Difference on Mapped Nodes

Looking at the coarse model and submodel results side by side, we see good agreement in the calculated temperatures.  The temperature in the fillets shows a nice, smooth gradient.

thermal-submodeling-18

Figure 18 – Coarse and Submodel Temperature Results Showing Good Agreement

Hopefully this explanation will be helpful to you if you have a need to perform submodeling in a thermal simulation in ANSYS.  There is a Thermal Submodeling Workflow section in the ANSYS 15.0 Help in the Mechanical User's Guide that you may find helpful as well.

 

 

 

Turkey, Team Building, and Spaghetti Towers: PADT’s Turkey Bowl 2014

IMG_0121

[EDITOR’S NOTE:  This was written some time ago and was set to automatically go out. But I just found it stuck in the “pending” folder.  So late, but here it is]  

It has been a great 20th anniversary year for PADT.  And we decided to close it out with some fun.  Now, if you know engineers, getting them to take part in any team building event is tough. And many of our employees came to PADT to get away from such things. The phrase "team building" causes a Pavlovian eye roll.  As we discussed options for November, we looked at a lot of activities. When we settled on doing an event that not only involved teams, but also color coded shirts, puzzles, and (gasp) a lean towards being healthier I said "we should try it, but it probably won't work" and hoped to be proven wrong. Even with the help of the great folks at Physix, I didn't have high hopes. But you don't know until you try.

I was proven wrong. 

Kickoff: Halloween and Pumpkin Launching

We started with a kickoff event on Halloween, which was nice enough to be on a Friday this year. In the past we have carved pumpkins and built a dry-ice pumpkin mortar.  This year we fed everyone to get them in a good mood and then put them in teams.  After some trivia contests we moved over the the first event – a pumpkin slingshot.

We finished up the kickoff event with rules and a list of ways to get points:  go to lunch with team mates, go for a hike, attend a class at Physix, get a fitness assessment, lose weight, answer the weekly quiz, and walk.  The easiest way to get points was to keep track of your step count.  

Three Weeks of Getting Points

The next three weeks were fun. Different teams approached things differently. Some opted to lunch together, often.

yhsfgn yhfgsdhsfh yfghdfhg ttertfg ttasn hhhhhhhhhhhhhh hhhhhhh ffffas fasdftrt fafrtyy asdfgg yujghj

Others did a fitness assessment or attended a class.  One team even tried to take a hike… on Photoshop:

ffffffffffff

Funny how their picture on Camelback Mountain looks a lot like their lunch picture…  

After a bit of a kerfuffle on Body Mass Index results from the fitness assessment, we held a brown bag seminar by the lake.  The reason why Physix is a great match for PADT is that their approach to health is science and fact based.  No chakra alignment here.  So Shannon came armed with statistics, studies, and fancy measuring devices with dials on them that we could write down numbers from.

yyyy 

There was also a weight loss competition.  Points for every pound lost. There are and will not be pictures from that portion of the event. But we can share that some people dropped a few pounds over the three week period, and some more than a few.  

Turkey and Contests 

At the end of the three weeks we gathered together again to take part in our annual Thanksgiving Feast, and compete to win some additional points for our teams.

lkasd;kifa

We started with a plank contest. Expecting 5 or so people to participate, maybe one from each team. Everyone gave it a shot:

IMG_4701

Most people lasted a minute, then they started to drop.  

IMG_4706

A ton of people lasted to 2 minutes, then 3, then 4.  6 people were holding at 4:30.

IMG_0142

Purple had a strong showing, Renee lasting past 5 minutes.  Clinton held strong for purple.  Don, and Demola held on for Orange and Black.

ssssssssssss

In the end, Demola won a ton of points for his team, lasting past 6 minutes.  

Next we tried a relay event that involved passing a ball over our heads and taking a step, then running to the back, then passing… what was that again. It took us a while to figure it out.  In hindsight, we should have created a process diagram before the event.  

IMG_0017

But Green and Black figured it out and charged to the finish line… not even stopping when one competitor stumbled.  No one left behind, as long as they have the right shirt color.

Inside, we had a timed puzzle building event. It got kind of nasty when the teams realized that each team had two pieces from another puzzle. People get aggressive when points are on the line.  There may have been some hiding, there may have been some prying of fingers open.

feverish puzzle activity

The last event was to build a tower out of spaghetti, string, tape, and a marshmallow. Whoever got their marshmallow the highest got the points.  Four of the teams built tripods and went for height.

IMG_0097

Two teams figured out that spaghetti bends and breaks.  Blue felt that building a box was better. I guess that is thinking outside the box?

IMG_0025

But the winner was a combination of tripod and "stoutness."  Green figured it out:

IMG_0063

There was a dessert contest as well. I grudgingly mention it because my dessert didn't make it into the finals… but I'm not bitter, not at all.

dessert contest

After that we all went back to work while the PADT HR and Physix teams summed up all the points and figured out who won.  

Green, thanks to their tower, squeaked into third place:

IMG_0217 

Some were happier than others about the competition.

Second place was won by the superior team, and we would have won if my dessert had been in the finals:

IMG_0125

And the winners were the Black Team.  

IMG_0132

You have to admit, they do look pretty confident.

What we Learned 

Overall, the three weeks were a nice distraction from a very busy period.  Some people that would not have normally spent time together, did. Some people learned a bit about fitness or nutrition that they didn't know before. A lot of people walked a lot more.  

We also learned a couple of lessons:

  1. You can have a positive and constructive team building event at a company that is kind of wired to go against such corporate group-think activities.

  2. Not everyone wants to participate. That's OK and it is no reason why those that do can't have fun.  And you can find small ways for people to take part.

  3. Some people are REALLY competitive. 

  4. The average core strength at PADT is stronger than we thought.

  5. The breath mints we got to combat coffee breath are 50 calories, and the average person has to walk around 500 steps to burn them off. 

  6. If you don't take these things too seriously, they can be fun and a nice break.

  7. PADT's employees are clever. They tried to get points for waking up in the morning and mouse clicks.  You have seen the Photoshop picture. They also wanted to pass off the PADT Medical skeleton as Don Pegg after his diet.  It didn't work.

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For those of you who are thinking of doing a similar event at your company, some key words of advice:

  1. Bring in someone to help that is a good fit for your culture. Don't try and fit a standard or large company approach to a small or medium company.  Find someone that gets you and maybe pushes your organization a bit further than you would push it on your own.

  2. Keep it short, keep it simple.

  3. Don't let the negative people drag it down. You will have some people that this is not a good fit for. If you try and please them, they will still be unhappy and it will lesson the event for others.  Just accept that not everyone will be on-board and move on.

  4. Place your tongue firmly in your cheek.  If you take these things too seriously, they will fail.  Make some fun of yourselves and the activity, it takes that edge off.

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If you do it right, you might even get engineers to touch each other.  

The Real Revolution in 3D Printing: It’s Normal

3D-printed-printerReading through my email this morning I saw an update from the "maker" site Instructables and I glanced at it quickly: "floating bed, how to make a sword, that's cool, 3D printable printer, folding chair charcoal forge, what?, parachord hammer holder, just buy one, duh, blah, blah, blah how do people have time for this… wait, 3D printable printer?" CLICK.  

So this 17 year old kid used his 3D Printer, an arduino board and parts he scrounged from old DVD drives to make a 3D Printer. Read about it here.  This kid, wootin24, designed and built an X, Y, Z positioning device that could be fited with a dremel tool to be a CNC machine, or an extruder to be a 3D Printer.  No CAD experience, no formal engineering training, just a smart person.  And the ad that popped up on the side of the how-to this kid wrote was for a Dremel 3D Printer, available at Home Depot. Not some kickstarter funded rehash of an opensource printer, Dremel. The big guys.  As I was feeling bad about how I spent my time when I was 17 (I'm not going to go there but I never did become a the backup bass player for Rush nor did I get a second date from T—–) and starting to worry about how systems from very capable companies like Dremel will impact our sales of Stratasys equipment, I realized that the true revolution in 3D printing happened and most of us involved day-to-day in the industry didn't even notice.  

3D Printing is Now Normal

When a revolutionary technology comes out there is a lot of hoopla and press. Tons of people start jumping on the bandwagon and your Aunt's friend in Topeka is sending you links on Facebook about 3D Printing and how it is "going to change everything."  Do not get me started on how 3D Printing is not new, we've been doing it at PADT for over 20 years, and certainly do not ask about the "3D printed gun.  The false-newness and fear-mongering stories are what the mainstream press picked up on. The good news is that the hype got the word out. And then smart people like this kid and the engineers at Dremel said "hmmm, that is useful. I can do something with this" and boom, the real revolution happened.  

After all these years this tool that was really a special tool used when needed, has become just another screwdriver in the toolbox.  A standard part of the process it is something most engineers understand well, and a majority of non-engineers are aware of. When we first started showing people our SLA machine back in the 90's they would either not understand what they were looking at or become flabergasted and amazed, treating it more like a magic box than a fairly simple additive curing system.  Now when we give tours we hear "that one looks like the one we have in our office" or "oh yea, an Objet, I'd love to trade my older system in for one of those." And the dreaded "oh, we have three of these in our robotics lab at school, do you have anything interesting?"  

3d-printers2
Amazon now has a section for all the 3D Printers they sell, just like headphones or video games.

So What

There is a lot of power in 3D Printing.  That is the real reason why the technology has blossomed as it has.  The power of 3D Printing is that it lets you make physical objects without special equipment or knowledge, the laser printer of manufacturing. However, as long as the tool is treated as something to be used in special cases or as a mystical new magic bullet, it will not be used correctly.  Now that it is mainstream, the use of additive manufacturing becomes mainstream and the power it brings to the table can be fully realized.  We see this every day at PADT. Product managers have "3D Printed Prototypes" as a standard line item in their budget templates.  Customers are increasingly talking about going back to their current product lines and identifying parts that are machined, injection molded, or cast and determining which can be replaced by 3D printed parts.  And most importantly, the supply chain and quality people are sniffing around and starting to make paperwork to control and manage 3D Printed components.  

As proponents of the technology since the early days, we could not be happier than when we see a check box for "Created with additive manufacturing" on a quality form. When it becomes part of the bureaucracy, the revolution has truly happened. 

Customer in the News: Soitec Sets Record for Solar Cell Efficiency at 46%

soitecWe noticed that customer and neighbor Soitec Phoenix Labs had a great writeup in the AZ Republic. Their substrate technology was used to make a multijunction solar cell for use with conentrated solar, delivering an amazing 46% efficiency. The standard right now in the mid to low 20% for single junction, the most common technology available. The article actually does a pretty good job of explaining the technology, why Soitec has something special, and some insight into their LED technology as well.

A big congrats to the team and we can not wait to hear when you break 50%!

They have a great video on their CPV efforts on their website.

Soitec is a french company that purchased GaNotec a few years back.  Their Phoenix Labs is across the lake in the ASU Research Park in the ASU MacroTechnology Works building and PADT has provided a variety of services to the company since it started as GaNotec.  We have worked with many of their employees at other Semiconductor Equipment companies before GaNotec was founded. 

Congrats to everyone!

soitec-HL

Press Release: Dedicated 3D Scanning Added to Round Out PADT’s Scanning Solutions

3d-optical-scanner-1

PADT has been offering 3D Scanning solutions for some time. Over time the company has added the sale of 3D Scanning hardware and software, training for 3D Scaning, and limited 3D Scanning services.  With the addition of a full time scanning engineer, PADT is now able to offer deciated scanning servcies to our customers.

Ademola Falada joins our team from Minnesota where he worked for a scanner manufacturer, CGI, for two years after graduating with an engineering degree from the University of Minnesota.  He brings extensive knowledge of scanning equipment and the scanning process.  Since joining PADT in the late summer, he has been providing limited services to our existing customers as he builds up our scanning capability and puts everything needed to provide a world class service in place.  He will be assisted by engineers and technicians that have been providing scanning on a part time basis in the past.

cross-sectional-scanning      

By offering optical and cross sectional scanning, PADT can provide a more accurate solution to a broader range of customers.  

Read the press release on this expanded service below

.Geomagic-Capture

You can also review our scanning services on our website

Or simply email us at rp@padtinc.com or call 480.813.4884 and our team will be more than happy to explain what we can do and provide you with a quote. 

 geomagic-qualify-probe-screenshot 

Press Release:

Dedicated 3D Scanning Added to Round Out PADT’s Scanning Solutions 

PADT now has a full time engineer and equipment dedicated to providing 3D Scanning services to customers.  Coupled with the sales and support of 3D scanners and software, PADT can now offer a complete solution to its growing number of scanning customers. 

Tempe, AZ – January 8, 2015 – Phoenix Analysis & Design Technologies, Inc. (PADT, Inc.), the Southwest’s largest provider of simulation, product development, and rapid prototyping services and products, is pleased to announce the addition of complete 3D part scanning to our services offering.  Based on growing customer requests, PADT has invested in equipment, software, and personnel to provide a dedicated resource in this area.  The company has been providing scanning as a service for many years, but on a part time basis when staff was free and customers could not find another resource.  PADT’s 3D Printing sales team has also been selling scanners and scanning software for over three years.  Bringing someone on board to focus on this critical need in product development was the next logical step.



3D Scanning is used by engineers to take a part in the real world and measure it accurately in order to get a model of the part on a computer.  This is done using a variety of technologies including lasers, patterned light, and high resolution pictures. The technology is used in product development to capture geometry of existing parts to reproduce (reverse engineering) them or design parts that attach or interact with them. It can also be used to inspect manufactured parts.



Ademola Falada joins our team from Minnesota where he worked for a scanner manufacturer, CGI, for two years after graduating with an engineering degree from the University of Minnesota.  He brings extensive knowledge of scanning equipment and the scanning process.  Since joining PADT in the late summer, he has been providing limited services to our existing customers as he builds up our scanning capability and puts everything needed to provide a world class service in place.  He will be assisted by engineers and technicians that have been providing scanning on a part time basis in the past.



“We are now ready to open our doors wide to customers who need accurate, timely, and useful scanning of their parts.” Commented Rey Chu, one of PADT’s owners and the Principal responsible for the company’s manufacturing services. “We never felt that we could deliver the level of service that customers expect from PADT until we had enough equipment and a dedicated engineer. We are there now.”



The scanning lab consists of two CGI Cross Sectional Scanners for high fidelity scanning of complex plastic parts with internal features, a Geomagic Capture blue light scanner, and a Steinbichler high resolution blue light scanner currently under evaluation. This combination of equipment is matched with the full suite of Geomagic scanning software to provide inspection data, cleaned point clouds, tessellated solids (STL), or usable CAD models. 



Customers who are interested in having parts scanned, or who want to learn more about the service, can contact the team at 480.813.4884 or scanning@padtinc.com 



Phoenix Analysis and Design Technologies, Inc. (PADT) is an engineering service company that focuses on helping customers who develop physical products by providing Numerical Simulation, Product Development, and Rapid Prototyping products and services. PADT’s worldwide reputation for technical excellence and an experienced staff is based on its proven record of building long term win-win partnerships with vendors and customers. Since its establishment in 1994, companies have relied on PADT because “We Make Innovation Work.“  With over 75 employees, PADT services customers from its headquarters at the Arizona State University Research Park in Tempe, Arizona, its Littleton, Colorado office, Albuquerque, New Mexico office, and Murray, Utah office, as well as through staff members located around the country. More information on PADT can be found at www.PADTINC.com.

Serial and Parallel ANSYS Mechanical APDL Simulations

ANSYS-APDL-Macro-PeDALThere are times when you want to study the effects of varying parameters.  If you have an existing MAPDL script that is parameterized, the following procedure will allow you to easily run many variations in an organized manner. 

Let’s assume a parameterized MAPDL macro called build_solve that does something you want to simulate many times and has 2 variables called power and scale which are set with argument 1 and 2 respectively.  Running this macro with the classic interface, with power=30 and scale=2.5 would look like this:

build_solve,30,2.5

Next, create a MAPDL macro to launch all of the simulations.  This script could be named control.mac.  The first thing to do here is to create arrays of your parameters and assign values to them.  This example will vary power and scale.  Here are the arrays of values that will be passed to build_solve:

*dim,power,array,4

power(1)=10,20,40,80

*dim,scale,array,6

scale(1)=1,2,3,5,10,20

Most of the control.mac commands will be put inside of nested *do loops.  There will be a *do loop for each of parameters being varied.

*do,ii,1,4

*do,jj,1,6

Next, use *cfopen to set up the arguments to be passed to build_solve.  Each time through the *do loops will create a new run1.mac

*cfopen,run1,mac

  a=power(ii)

  b=scale(jj)

  *vwrite,a,b

  build_solve,%G,%G

*cfclose

One of the key features of this approach is to run anywhere and build directories below the working directory.  Use the /inquire command to store the current directory name.

/INQUIRE,dir_,DIRECTORY

Use *cfopen to create a string that will be used for the directory name.  By using the variables as part of the string, the directories will have unique names.  A time or date stamp could also be included in this string.  This macro is executed immediately to create the string dirnam for use in the commands subsequently.

*dim,power,array,4

*cfopen,temp1,mac

*vwrite,a,b

dirnam='power_%G_scale_%G'

*cfclose

/input,temp1,mac

Eventually, the resulting directory structure will look something like the image below.  Each directory will contain a separate simulation with the arguments of power and scale set respectively.

mapdl-script-automation

The last *cfopen creates a windows batch file which will (when executed)

  1. Create the new directory

  2. Copy all of the macro files from the working directory into the new directory (including run1.mac)

  3. Change into the new directory using CD

  4. Launch ansys in batch mode, in this case using a gpu and 12 cpus, using the run1.mac input and outputting to f.out

  5. Change back to the working directory (ready to do it all again)

The code for the windows batch file is:

*cfopen,rfile,bat

*vwrite,dir_(1),dirnam

MKDIR "%C\%S"

*vwrite,dir_(1),dirnam

COPY *.mac "%C\%S"

*vwrite,dir_(1),dirnam

CD "%C\%S"

*vwrite,

"C:\Program Files\ANSYS Inc\v150\ansys\bin\winx64\ansys150" -b -acc nvidia -np 12 -i run1.mac -o f.out

*vwrite,dir_(1)

CD "%C"

*cfclose

The last step is to run the windows batch file.  /sys is used to make this system call.  If the simulation is not well parallelized and you have enough licenses available, run the simulations in low priority mode immediately.  This will launch all of your simulations in parallel:

  • /sys,start /b /low rfile.bat

If the model is well parallelized (in other words, it will use your system’s gpu/cpus/RAM efficiently) or you only have 1 license available, launch the batch files in high priority mode and use the /wait option which will insure that windows waits for the job to finish before launching the next simulation.

  • /sys,start /b /high /wait rfile.bat

You can download and view the examples control.mac and build_solve.mac from this zip file: build_solve-control-macros.zip

ANSYS 2015 Hall of Fame Announced – Los Alamos National Labs and SynCardia Models are Finalists

2015-hall-of-fame-header-closed

Every year for a while now ANSYS, Inc. has chosen models made by users of the ANSYS software tools for their Hall of Fame.  This year had some very cool models across CFD, Structural, and Electromagnetic – including some great Multiphysics applications. Visit the ANSYS website to see all the winners here.

The three commercial winers of "Best in Show" were varied but powerful examples of how simulation can be used to improve performance and reliability of products:

 best-in-show-2015-ansys-hall-of-fame

Andritz Hydro used ANSYS Mechanical to model their assemblies to see if replacing welds with bolted joints would reduce weight and cost while keeping reliability.  They used sub-modeling, bolted joints, and contact.  

BRP used ANSSY CFX, ICEM CFD, and Mechanical to capture the forces caused by cavitation on their outboard marine engine. This engine pushes a boat at 75MPH (!!!) through the water, so yes, they get cavitation.  They used ICEM CFD for meshing, CFX to predict the cavitation and capture the cavitation loading, and Mechanical to see how the loading impacted the gear train and shafts. They were able to obitmize the desgin quickly using this process.

Spinologics used ANSYS Mechanical APDL to model the process of using a rod to straighten a deformed spine (scoliosis). They use the scriptability of the APDL to automate the creation of the models.  Very cool stuff.  Check out the video on the link.

We also want to mention two customers that were involved as Finalists.  

syncardia-heartSynCardia is often mentioned in this blog because, well, they make a frick'n artificial heart that saves lives every day.  We modeled an early iteration on the heart as a multiphysic problem probobly 5 or 6 years ago, it could have been longer ago. More recently Stony Brook University and the University of Arizona did a much more detailed model in ANSYS Fluent that looks at not just pressure and velocity, but Platelet dispersion patterns in the artificial heart.  Check out the video here:  https://storage.ansys.com/hof/2015/video/2015-stonybrook.mp4

2015-lanl-bgLos Alamos National Labs is another long time PADT customer and we were fortunate enough to be involved in the study that was recognized as a finalist. They used ANSYS Fluent to model something called vortex-induced motion or VIM in off-shore oil rigs.  Basically waves hit the platform and create these big swirling vortices.  These in turn put loads on the structure that can sometimes be very large.  The purpose of this study was to find a way to accurate predict VIM with simulation so they could then evaluate various solutions. A true Fluid-Solid Interaction (FSI) and because of the size of the structures and all that turbulence, High Performance Computing (HPC) problem. We hope to publish a paper on some related work this year… watch this space for more.

 This competition is a great way to see what others are doing, and if you submit your models, to show off what you have done.  Contact your ANSYS rep to learn more or drop us a note.

 

ANSYS Icepak: Diverging Residuals, Find and Fix the Problem!

Over the past week I have found myself dealing with a stubborn natural convection ANSYS Icepak model with convergence plots that would have been more aptly named divergence plots that looked like this:

pic2

In this post I’m going to show you the process I went through to find and fix my problem.

First, a few things to know about Icepak:

  • Many of the problems associated with your Icepak model are very likely mesh related.

  • If the bad elements are in a solid, you are probably OK, but if they are in the fluid, watch out!!

So, what is the conclusion? I have a mesh problem.

Second, how do you find the problem?

According to the above “convergence” plot, the continuity equation is diverging (or to my frustrated, on-a-deadline mind, it was GOING CRAZY). Well, a diverging continuity equation indicates that I have a conservation of mass problem. After consulting with one of my more experienced colleagues, Clinton Smith, he suggested that I do the following to work towards pin-pointing the problem:

  • Plot the gravity direction velocity (in my case, this was Uy)

  • Look for the Minimum and Maximum Uy locations in the model

Plotting Uy along a cut plane produced this:

ansys-icepack-diverging-residuals-3

ansys-icepack-diverging-residuals-4

As Clinton thought, plotting Uy instantly showed me the section of my model that was producing un-physical results. Next, I looked for the maximum and minimum velocity locations because this would further show me problems.

ansys-icepack-diverging-residuals-6

ansys-icepack-diverging-residuals-5

Next, I need to determine why this area of my model is the problem. Like I said above, it is likely a mesh problem. In the Mesh Control panel under the Quality tab checking the Face alignment values often help to locate very bad elements:

ansys-icepack-diverging-residuals-7

Clicking on the pink block above displays the elements in the graphics window and it was instantly obvious that my problem was due to distorted elements in my area of interest:

ansys-icepack-diverging-residuals-8

ansys-icepack-diverging-residuals-9

When I look at these elements with a perspective of my model geometry I see that the elements are obviously in the fluid domain:

ansys-icepack-diverging-residuals-10

ansys-icepack-diverging-residuals-11

I have found my problem.

Third, how do I fix the problem? Well, the location of my bad elements happens to lie on a CAD body in Icepak. This means that I am limited in my ability to control the mesh on the actual body. So, though there are likely multiple ways that this problem could be solved, I had the idea to create an air block in the area above that I could much more easily control from a meshing perspective. Having a real Icepak primitive in that space would force the mesher to conform to the boundary of the CAD body.

ansys-icepack-diverging-residuals-12

Like I thought, the air block worked!

ansys-icepack-diverging-residuals-13

I should note that in order to get the mesh to conform exactly, I had to put the air block into its own meshed-separately assembly. And now my residuals look much better!

ansys-icepack-diverging-residuals-14

Summary:

  • Diverging continuity residuals indicate a conservation of mass problem

  • Plot velocities to locate problem region

  • Plot min/max velocity to further identify problem

  • If bad elements are in the fluid region, they must be fixed

  • Consider creating an air block in the region of interest to more finely control the mesh