Using External Data in ANSYS Mechanical to Tabular Loads with Multiple Variables, Part 2

ANSYS Mechanical is great at applying tabular loads that vary with an independent variable. Say time or Z.  What if you want a tabular load that varies in multiple directions and time. In part one of this series, I covered who you can use the External Data tool to do just that. In this second part, I show how you can alternatively use APDL commands added to your ANSYS Mechanical model to define the tabular loading.

PADT-ANSYS-Tabular-loads-2

Mechanical Meshing Enhancements in ANSYS 18 and Beyond – Webinar

ANSYS Meshing is a general-purpose, intelligent, automated high-performance product that helps engineers to produce the most appropriate mesh for accurate, efficient multi-physics solutions.

With the release of ANSYS version 18 earlier this year, engineers were introduced to a variety of new and innovative enhancements that help improve the quality of their meshing, and speed up the simulation process.

Join PADT’s Simulation Support Manager Ted Harris, for an in depth look at new mechanical meshing capabilities made available in ANSYS 18.0, 18.1 and 18.2!

This free webinar will cover a variety of new and improved capabilities within the latest version of ANSYS, including:

  • Improved diagnostics/mesh metrics
  • More flexible mesh controls
  • New physics preference for Hydrodynamics
  • and much more!

Don’t miss this informative presentation – Secure your spot today!

If this is your first time registering for one of our Bright Talk webinars, simply click the link and fill out the attached form. We promise that the information you provide will only be shared with those promoting the event (PADT).

You will only have to do this once! For all future webinars, you can simply click the link, add the reminder to your calendar and you’re good to go!

Six Very Useful Enhancements in ANSYS Mechanical 18

By now you’ve probably heard that ANSYS versions 18.0, 18.1, and 18.2 have all been released in 2017. While 18.0 was the ‘point’ release in January, it should be noted that 18.1 and 18.2 are not ‘patches’ or service packs, but are full releases each with significant enhancements to the code. We’ll present some significant and useful enhancements for each.

18.0

Number 1: First and foremost – info on the new features is more readily accessible with the Mechanical Highlights list. The first time you launch Mechanical, you’ll see a hyperlinked list of new release highlights.

One you actually do something in Mechanical, though, that list goes away. There is a simple way to get it back: Click on the Project branch in the Mechanical tree, then click on the Worksheet button in the menu near the top of the window.
Clicking on the hyperlinks in the list or simply scrolling down gives us more information on each of the listed enhancements. Keep in mind the list is only highlights and by no means has all of the new features listed. A more detailed list can be found in the ANSYS Help, in the Release Notes.

Number 2: A major new feature that became available in 18.0 is Topology Optimization. We’ve written more about Topology Optimization here

Number 3: Another really useful enhancement in 18.0 is the ability to define a beam connection as a pretensioned bolt. This means we no longer need to have a geometry representation of a bolt if we want a simpler model. We can simply insert a beam connection between the two sides of the bolted geometry, and define the pretension on that resulting beam.
Beam connections are inserted in the Connections branch in Mechanical. Once the beam is fully defined, it can have a bolt pretension load applied to it, just like as if the beam geometry was defined as a solid or beam in your geometry tool. Here you can see a beam connection used for bolt pretension on the left, with a traditional geometric representation of a pretensioned bolt on the right:

18.1

Number 4: A very nice capability added in version 18.1 is drag and drop contact regions for contact sizing in the Mesh branch. Contact elements work best when the element sizes on both sizes of the interface are similar, especially for nonlinear contact. ANSYS Mechanical has had Contact Sizing available as a mesh control for a long time. Contact Sizing allows us to specify an element size or relevance level once, for both sides of one or more contact regions.

What’s new in 18.1 is the ability to drag and drop selected contacts from the Connections branch into the Mesh branch. Just select the desired contact regions with the mouse, then drag that selection into the Mesh branch. Then specify the desired mesh sizing controls for contact.
This is what the dragging and dropping looks like:

After dropping into the Mesh branch, we can specify the element size for the contact regions:

This shows the effect of the contact sizing specification on the mesh:

18.2

Number 5: An awesome new feature in 18.2 is element face selection, and what you can do with it. There is a new selection filter just for element face selection, shown here in the red box:


Once the element face select button is clicked, element faces can be individually selected, box selected, or paint selected simply by holding down the left mouse button and dragging. The green element faces on the near side have been selected this way:

The selected faces can then be converted to a Named Selection, or items such as results plots can be scoped to the face selection:

Number 6: Finally, to finish up, some new hotkeys were added in 18.2. Two really handy ones are:

  • Z = zoom fit or zoom to the current selection of entities
  • <Ctrl> K = activate element face selection
  • F11 = make the graphics window full screen!
  • Click F11 again to toggle back to normal size

Please realize that this list is just a tiny subset of the new features in ANSYS 18. We encourage you to try them out on your own, and investigate others that may be of benefit to you. Keep the Mechanical Highlights list from Number 1 in mind as a good source for info on new capabilities.

All Things ANSYS EP001: Topological Optimization and other additions in ANSYS 18

Published on: July 31, 2017
With: Trevor Rubinoff, Joe Woodward, Ted Harris, and Eric Miller
Description: In our first ever attempt at a podcast we gather a few engineers around microphone and share our thoughts. Besides talking about our new podcast, we take a look at what we have learned about Topological Optimization with ANSYS as well as each of our favorite features in ANSYS 18. We also introduced a regular segment where we go over news in the ANSYS world.
Listen:
Subscribe:

 

ANSYS 18 Mechanical Ease of Use Webinar – Coming Soon

We here at PADT are proud to present the ease of use and productivity enhancements that have been added to ANSYS Mechanical in release 18.

With this new release, ANSYS Mechanical focuses on the introduction of a variety of improvements that help save the users time, such as smarter data organization and new hotkeys, along with additions that can help you to better visualize specific intricacies in your models.

This webinar is coming up soon

Join PADT’s Simulation Support & Application Engineer Doug Oatis for an overview of the current user friendly interfaces within ANSYS Mechanical, along with the numerous additions in this new release that help to improve efficiency tenfold, such as:

Pretension Beam Connection

A beam connection is a power idealization to connect parts without modeling the bolts. Now the beam connection can be pretensioned as well.

Register today to find out how you can use this highly requested feature and many others to improve your throughput and stay ahead of the curve!

Making Thermal Contact Conductance a Parameter in ANSYS Mechanical 18.0 and Earlier with an APDL Command Object

A support request from one of our customers recently was for the ability to make Thermal Contact Conductance, which is sort of a reciprocal of thermal resistance at the contact interface, a parameter so it can be varied in a parametric study.  Unfortunately, this property of contact regions is not exposed as a parameter in the ANSYS Mechanical window like many other quantities are.

Fortunately, with ANSYS there is almost always a way……in this case we use the capability of an APDL (ANSYS Parametric Design Language) command object within ANSYS Mechanical.  This allows us to access additional functionality that isn’t exposed in the Mechanical menus.  This is a rare occurrence in the recent versions of ANSYS, but I thought this was a good example to explain how it is done including verifying that it works.

A key capability is that user-defined parameters within a command object have a ‘magic’ set of parameter names.  These names are ARG1, ARG2, ARG3, etc.  Eric Miller of PADT explained their use in a good PADT Focus blog posting back in 2013

In this application, we want to be able to vary the value of thermal contact conductance.  A low value means less heat will flow across the boundary between parts, while a high value means more heat will flow.  The default value is a calculated high value of conductance, meaning there is little to no resistance to heat flow across the contact boundary.

In order to make this work, we need to know how the thermal contact conductance is applied.  In fact, it is a property of the contact elements.  A quick look at the ANSYS Help for the CONTA174 or similar contact elements shows that the 14th field in the Real Constants is the defined value of TCC, the thermal contact conductance.  Real Constants are properties of elements that may need to be defined or may be optional values that can be defined.  Knowing that TCC is the 14th field in the real constant set, we can now build our APDL command object.

This is what the command object looks like, including some explanatory comments.  Everything after a “!” is a comment:

! Command object to parameterize thermal contact conductance
! by Ted Harris, PADT, Inc., 3/31/2017
! Note: This is just an example. It is up to the user to create and verify
! the concept for their own application.

! From the ANSYS help, we can see that real constant TCC is the 14th real constant for
! the 17X contact elements. Therefore, we can define an APDL parameter with the desired
! TCC value and then assign that parameter to the 14th real constant value.
!
! We use ARG1 in the Details view for this command snippet to define and enable the
! parameter to be used for TCC.

r,cid ! tells ANSYS we are defining real constants for this contact pair
! any values left blank will not be overwritten from defaults or those
! assigned by Mechanical. R command is used for values 1-6 of the real constants
rmore,,,,,, ! values 7-12 for this real constant set
rmore,,arg1 ! This assigned value of arg1 to 14th field of real constant

! Now repeat for target side to cover symmetric contact case
r,tid ! tells ANSYS we are defining real constants for this contact pair
! any values left blank will not be overwritten from defaults or those
! assigned by Mechanical. R command is used for values 1-6 of the real constants
rmore,,,,,, ! values 7-12 for this real constant set
rmore,,arg1 ! This assigned value of arg1 to 14th field of real constant

You may have noticed the ‘cid’ and ‘tid’ labels in the command object.  These identify the integer ‘pointers’ for the contact and target element types, respectively.  They also identify the contact and target real constant set number and material property number.  So how do we know what values of integers are used by ‘cid’ and ‘tid’ for a given contact region?  That’s part of the beauty of the command object: you don’t know the values of the cid and tid variables, but you alsp don’t need to know them.  ANSYS automatically plugs in the correct integer values for each contact pair simply by us putting the magic ‘cid’ and ‘tid’ labels in the command snippet.  The top of a command object within the contact branch will automatically contain these comments at the top, which explain it:

!   Commands inserted into this file will be executed just after the contact region definition.
!   The type number for the contact type is equal to the parameter “cid”.
!   The type number for the target type is equal to the parameter “tid”.
!   The real and mat number for the asymmetric contact pair is equal to the parameter “cid”.
!   The real and mat number for the symmetric contact pair(if it exists)
! is equal to the parameter “tid”.

Next, we need to know how to implement this in ANSYS Mechanical.  We start with a model of a ball valve assembly, using some simple geometry from one of our training classes.  The idea is that hot water passes through the valve represented by a constant temperature of 125 F.  There is a heat sink represented at the OD of the ends of the valve at a constant 74 degrees.  There is also some convection on most of the outer surfaces carrying some heat away.

The ball valve and the valve housing are separate parts and contact is used to allow heat to flow from the hotter ball valve into the cooler valve assembly:

Here is the command snippet associated with that contact region.  The ‘magic’ is the ARG1 parameter which is given an initial value in the Details view, BEFORE the P box is checked to make it a parameter.  Wherever we need to define the value of TCC in the command object, we use the ARG1 parameter name, as shown here:

Next, we verify that it actually works as expected.  Here I have setup a table of design points, with increasing values of TCC (ARG1).  The output parameter that is tracked is the minimum temperature on the inner surface of the valve housing, where it makes contact with the ball.  If conductance is low, little heat should flow so the housing remains cool.  If the conductance is high, more heat should flow into the housing making it hotter.  After solving all the design points in the Workbench window, we see that indeed that’s what happens:

And here is a log scale plot showing temperature rise with increasing TCC:

So, excluding the comments our command object is 6 lines long.  With those six lines of text as well as knowledge of how to use the ARG1 parameter, we now have thermal contact conductance which varies as a parameter.  This is a simple case and you will certainly want to test and verify for your own use.  Hopefully this helps with explaining the process and how it is done, including verification.

 

 

 

ANSYS 18 – Mechanical Ease of Use Webinar

We here at PADT are proud to present the ease of use and productivity enhancements that have been added to ANSYS Mechanical in release 18.

With this new release, ANSYS Mechanical focuses on the introduction of a variety of improvements that help save the users time, such as smarter data organization and new hotkeys, along with additions that can help you to better visualize specific intricacies in your models.

Join PADT’s Simulation Support & Application Engineer Doug Oatis for an overview of the current user friendly interfaces within ANSYS Mechanical, along with the numerous additions in this new release that help to improve efficiency tenfold, such as:

  • Hotkey Additions
  • Box Geometry Creation Within Mechanical
  • Free Standing Remote Points
  • Improved Status Bar Information
  • Pretension Beam Connection
  • Solver Scratch Directory Specification
  • Improved Probe Annotations

Register today to find out how you can use these enhancements to improve your throughput and stay ahead of the curve!

We look forward to seeing you there.

ANSYS 18 – AIM Enhancements Webinar

We here at PADT are excited to share with you the updates that ANSYS 18 brings to the table for AIM: The easy-to-use, upfront simulation tool for all design engineers.

ANSYS AIM is a single GUI, multiple physics tool with advanced ANSYS technology under the hood. It requires minimal training and is interoperable with a wide range of ANSYS simulation products.

Join PADT’s application engineer Tyler Smith as he covers the new features and capabilities available in this new release, including:

  • Magnetic frequency response
  • One-way FSI for shell structures
  • Model transfer to Fluent
  • One-way magnetic-thermal coupling
  • and many more!

ANSYS AIM is a perfect tool for companies performing simulation with a CAD embedded tool, design engineers at companies using high end simulation, and even companies who have yet to take the plunge into the world of simulation.

Register for this webinar today and learn how you can take advantage of the easy-to-use, yet highly beneficial capabilities of ANSYS AIM.

Using External Data in ANSYS Mechanical to Tabular Loads with Multiple Variables

ANSYS Mechanical is great at applying tabular loads that vary with an independent variable. Say time or Z.  What if you want a tabular load that varies in multiple directions and time. You can use the External Data tool to do just that. You can also create a table with a single variable and modify it in the Command Editor.

In the Presentation below, I show how to do all of this in a step-by-step description.

PADT-ANSYS-Tabular-Loading-ANSYS-18

You can also download the presentation here.

PADT Events – February 2017

Although February is a short month, we have lots of activities scheduled to talk about new releases from both ANSYS and Stratasys as well as a STEM and Medtech event. Take a look for details below or visit the bottom of our home page to see the latest.


Arizona Science Bowl

02/04/17
ASU West Campus
Glendale, AZ

PADT will be attending this great event for middle and high schools. Dr. Bhate will be speaking to the middle school students
Learn more

2017 Stratasys New Product Launch Webinar

02/09/17
Online

Stratasys is introduce some new products and you are invited to attend online to learn how once again they will advance 3D Printing to the next level. PADT’s engineers will not just share information about these new systems, they will also explain what we thing is important about each machine and what its new advantages are.
Learn more

ANSYS 18 – Mechanical APDL & HPC Update Webinar

02/14/17
Online

ANSYS is rolling out a new version of their entire software platform, and we are offering seminars to help users understand what is new and cool. This first webinar will be focused on ANSYS Mechanical APDL and what is going on way deep under the hood.
Learn more

AZ Tech Council MedTech
Conference, 2017

02/23/17
Spear Education
Scottsdale, AZ

Medtech has grown a lot in Arizona over the past couple of years, so the Tech Council is putting on an event for everyone involved to get together to network and learn. PADT will have a booth and will be talking about 3D Printing in medical devices. If you are at all involved in medical technology, you should attend.
Learn more

ANSYS 18 – HPC Licensing Update Webinar

02/28/17
Online

ANSYS is rolling out a new version of their entire software platform, and we are offering seminars to help users understand what is new and cool. This second webinar will be focused on ANSYS HPC licensing and how that has changed.
Learn more