Continue a Workbench Analysis in ANSYS MAPDL R15

stopsignThis article outlines the steps required to continue a partially solved Workbench based analysis using a Multi-Frame Restart and the MAPDL Batch mode.

In this article you will learn:

  • Some ways to interface between ANSYS Workbench and ANSYS MAPDL
  • How to re-launch a run using a Multi-Frame Restart in ANSYS Batch mode
  • The value of the jobname.abt functionality for Static Structural and Transient Structural analyses

Recently I was working in the ANSYS Workbench interface within the Mechanical application running a Transient Structural analysis. I began my run thinking that my workstation had the necessary resources to complete the analysis in a reasonable amount of time. As the analysis slowly progressed, I began to realize that I needed to make a change and switch to a computer that had more resources. But some of my analysis was already complete and I did not want to lose that progress. In addition, I wanted to be sure that I could monitor the analysis intermediately to ensure that it was advancing as I would like. This meant that however I decided to proceed I needed to make sure that I could still read my results back into Mechanical along with having the capability to restart again from a later point. Here were my options.

1: I could use the Remote Solve Manager (RSM) to continue running my analysis on a compute server machine. Check out this article for more on that.

I did use RSM in part but perhaps you do not have RSM configured or your computer resources are not connected through a network. Then I will show the other option you can use.

2: A Multi-Frame Restart using MADPL in ANSYS Batch mode

Here’s the process:

1. Make note of the current load step and last converged substep that your analysis completed when you hit the Interrupt Solution button
rs1

2. Copy the *.rdb, *.ldhi, *.Rnnn files from the Solver Files Directory on the local machine to the Working Directory on the computing machine
rs2

You can find your Solver Files Directory by right clicking on the Solution Branch in the Model Tree and selecting Open Solver Files Directory:
p1

3. Write an MAPDL input file with the commands to launch a restart and save it in the Working Directory on the computing machine (save with extension *.inp)

Below is an example of an input that will work well for restarting an analysis, but feel free to adjust it with the understanding that the ANSYS Programming Design Language (APDL) is a sophisticated language with a vast array of capability.
rs4

4. Start the MADPL Product Launcher interface on the computing machine and:
    a: Set Simulation Environment to ANSYS Batch
    b. Navigate to your Working Directory
    c. Set the jobname to the same name as that of the *.rdb file
    d. Browse to the input file you generated in Step 3
    e. Give your output file a descriptive name
    f. Adjust parallel processing and memory settings as desired
    g. Run

rs5

5. Look at the output file to see progress and monitor the run
rs6
rs7

6. Write “nonlinear” in a text file and save it as jobname.abt inside the Working Directory to cleanly interrupt the run and generate restart files when desired
rs8

rs9
The jobname.abt will appear briefly in the Working Directory

rs10
The output file will read the following:
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Note that the jobname.abt interruption process is the exact process that ANSYS uses in the background when the Interrupt Solution button is pressed interactively in Mechanical
rs12

Read more about the jobname.abt functionality in the Help Documentation links at the end of this article.

7. Copy all newly created files in Working Directory on the computing machine to the Solver Files Directory on the local machine
rs13

8. Back in the Mechanical application, highlight the Solution branch of the model tree, select Tools menu>Read Results Files… and navigate to the Solver Files Directory and read the updated *.rst file
rs14

After you have read in the results file, notice that the restart file generated from the interruption through the jobname.abt process appears as an option within the Mechanical interface under Analysis Settings
rs15

9. Review intermediate results to determine if analysis should continue or if adjustments need to be made

10. Repeat entire process to continue analysis using the new current loadstep and substep

Happy solving!

Here are some useful Help Documentation sections in ANSYS 15 for your reference:

  • Understanding Solving:
    • help/wb_sim/ds_Solving.html
  • Mechanical APDL: Multiframe Restart:
    • help/ans_bas/Hlp_G_BAS3_12.html#BASmultrestmap52199

And, as always, please contact PADT with your questions!

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Video Tips: Create and Display Custom Units in ANSYS CFD-Post

By: Susanna Young

ANSYS CFD-Post is a powerful tool capable of post-processing results from multiple ANSYS tools including FLUENT, CFX, and Icepak. There are almost endless customizable options in ANSYS CFD-Post. This is a short video demonstrating how to create and display a set of custom units within the tool. Stay tuned for additional videos on tips for more effective post-processing in ANSYS CFD-Post.

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ANSYS Remote Solve Manager (RSM): Answers to Some Frequently Asked Questions

rsm-1For you readers out there that use the ANSYS Remote Solve Manager (RSM) and have had one or all of the below questions, this post might just be for you!

  1. What actually happens after I submit my job to RSM?
  2. Where are the files needed to run the solve go?
  3. How do the files get returned to the client machine, or do they?
  4. What if something goes wrong with my solve or in the RSM file downloading process, is there any hope of recovery?
  5. Are there any recommendations out there for how best to use RSM?

If your question is, how do I setup RSM as a user? You answers are here from a post by Ted Harris. The post today is a deeper dive into RSM.

The answers to questions 1 through 3 above are really only necessary if you would like to know the answer to question 4. My reason for giving you a greater understanding of the RSM process is so that you can do a better job of troubleshooting should your RSM job run into an issue.  Also, please note that this process is specifically for an RSM job submitted for ANSYS Mechanical. I have not tested this yet for a fluid flow run.

What happens when a job gets submitted to RSM?

The following will answer questions 1-3 above.

When a job is run locally (on your machine), ANSYS uses the Solver Files Directory to store and update data. That folder can be found by right clicking on the Solution branch in the Model tree and selecting Open Solver Files Directory.

p1
The project directory will be opened and you can see all of the existing files stored for your particular solution:
p2

When a job gets submitted to RSM, the files that are stored in the above folder will be transferred to a series of two temporary directories. One temporary directory on the client side (where you launched the job from) and one temporary directory on the compute server side (where the numbers get crunched).

After you hit solve for a remote solve, you will notice that your project solver directory gets emptied. Those files are transferred to a temporary directory under the _ProjectScratch directory:
p3 p4

p5
Next, these files get transferred to a temporary directory on the compute server. The files in the _ProjectScratch directory will remain there but the folder will not be updated again until the solve is interrupted or finished.

You can find the location of the compute server temporary directory by looking at the output log in the RSM queueing interface:
p6

If you navigate to that directory on your compute server, you will see all of the necessary files needed to run. Depending on your IT structure, you may or may not have access to this directory, but it is there.

Here is a graphical overview of the route that your files will experience during the RSM solve process.
 ss1ss2

Once your run is completed or you have interrupted it to review intermediate results and your results have been downloaded and transferred to the solver files folder, both of the temporary directories get cleaned up and removed. I have just outlined the basic process that goes on behind the scenes when you have submitted a job to RSM.

What if something goes wrong with my RSM job? Can I recover my data and re-read it into Workbench?

Recently, I ran into a problem with one of my RSM jobs that resulted in me losing all of the data that had been generated during a two day run. The exact cause of this problem I haven’t determined but it did force me to dive into the RSM process and discover what I am sharing with you today. By pin-pointing and understanding what goes on after the job is submitted to RSM, I did determine that it can be possible to recover data, but only under certain circumstances and setup.

First, if you have the “Delete Job Files in Working Directory” box checked in the compute server properties menu accessed from the RSM queue interface (see below) and RSM sees your job as being completed, the answer to the above question is no, you will not be able to recover your data. Essentially, because the compute server is cleaned up and the temporary directory gets deleted, the files are lost.
p9

To avoid lost data and prepare for such a catastrophe, my recommendation is that you or your IT department, uncheck the “Delete Job Files in Working Directory” box. That way, you have a backup copy of your files stored on the server that you can delete later when you are sure you have all of your files safely transferred to your solver files folder within your project directory structure.

The downside to having this box unchecked is that you have to manually cleanup your server. Your IT department might not like, or even allow you to do this because it could clutter your server if you do not stay on top of things. But, it could be worth the safety net.

As for getting your data back into Workbench, you will need to manually copy the files on the compute server to your solver files folder in your Workbench project directory structure. I explained how to access this folder at the beginning of this post. Once you have copied those files, back in the Mechanical application, with the Solution branch of your model tree highlighted, selects Tools>Read Results Files… (see below graphic), navigate to your solver files directory, select the *.rst file and read it in.

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Once the results file is read in, you should see whatever information is available.

Recommendations

  • Though it is possible to run concurrent RSM jobs from the same project, my recommendation is to only run one RSM job at a time from the same project in order to avoid communication or licensing holdups

  • Unless you are confident that you will not ever need to recover files, consider unchecking the “Delete Job Files in Working Directory” box in the compute server properties menu.

    • Note: if you are not allowed access to your compute server temporary directories, you should probably consult your IT department to get approval for this action.

    • Caution: if you uncheck this box, be sure that you stay on top cleaning up your compute server once you have your files successfully downloaded

  • Depending on your network speed, when your results files get large, >15GB, be prepared to wait for upload and download times. There is likely activity, but you might not be able to “see” it in the progress information on the RSM output feed. Be patient or work outside of RSM using a batch MAPDL process.

  • Avoid hitting the “Interrupt Solution” command more than once. I have not verified this, but I believe this can cause mis-communication between the compute server and local machine temporary directories which can cause RSM to think that there are no files associated with your run to be transferred.

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3D Printer/Scanner Bundles Now Available

We are very excited to offer 3 different 3D Printer and Scanner bundles to our customers. Each contain a variety of products to help you achieve optimal results.  They are all products that we use here at PADT everyday.  It is everything you need for 3D Scanning & Printing that works!

cubeGeomagic Capture Scanner and Mojo 3D printer bundle
Enjoy a commercial level 3D scanner and printer combo at an affordable entry level price.  This bundle starts with a Geomagic Capture Scanner coupled with Geomagic Wrap software enabling users to easily and accurately scan a physical model and transform point cloud data, probe data and imported 3D formats (STL, OBJ, etc.) into 3d polygon meshes for use in manufacturing, design and analysis. Because we know your time is valuable, this bundle also includes a geoCUBE computer workstation built specifically for handling the large number of data points typically encountered when performing scanning.  Finally, print your model in your choice of a variety of colors on ABSplus using your Mojo 3D printer. With this bundle you can easily go from scan to print with for only $25,899. Training is included.

mojo_designer_in_cubicle
Departmental Desktop Printing Solutions
The Mojo 3D printer from Stratasys is a great solution to start making quality, duarable 3D models – right out of the box.  And now the price makes it even more affordable to have a 3D printer in every department.  A Mojo 3D printer with material package and Support Cleaning system now starts at $5,999 but we are offering a bundle discount for all your departmental needs with prices starting at $28,995 for 5 and $57,490 for 10 Mojos.  Everything you need to get a 3D printer on every floor!


uprint_se_3d_print_packEntry-level Reverse Engineering and Printing 
This entry-level reverse engineering package starts with a Geomagic Capture scanner with Geomagic Wrap software so that you can seamlessly scan and process data. Construct a usable CAD model from your scan data using SpaceClaim’s geometry creation tools.  Everything runs on the included geoCUBE computer workstation that efficiently handles the large amounts of data produced.  When you are ready to print your design,  you can use the included uPrint se Plus.  This all-in-one solution helps you save on design time and reduce outsourcing costs by bringing it all in-house starting at $41,400 including training. 

Bundles are available through 12/31/14.  Contact us for more info.

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Join us in Colorado for a 3D printing Demo

happyhour563dprinting

PADT Colorado is excited to be partnering again with Alignex for a 3D printer demo/happy hour at their upcoming networking event.  

The event is from 10 am to 6pm and will feature guest speakers discussing the latest in engineering and design productivity.  PADT will be on site to discuss 3D printing during their happy hour from 5 to 6pm. 

For more details and to register for the event please click here.

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Four Events to Help Celebrate Manufacturing in Arizona

logo_revaz

The month of October in Arizona is Manufacturer’s Month. Part of the Arizona Commerce Authoritie’s RevAZ program, this month of celebrations is an opportunity for those of us who make stuff, or support people to make stuff, to spread the word that the manufacturing community is robust, diverse, and has a major impact on the local economy.

Learn more on the RevAZ site: www.manufacturingrevolution.com 

PADT is attending three events, and hosting the closing event for the month. We hope to run in to you at the first three, and consider this the first of many invitations to join us for an open house and celebration on October 30th.

The three events open to the public are:

October 3rd, 2014 – 10:00 to 2:00
National Manufacturing Day Open House at AzAMI

The Arizona Advanced Manufacturing Institute (AzAMI) at Mesa Community College (MCC) is celebrating National Manufacturing Day by opening its doors to the community. Guided Tours of its enhanced machining, processing and additive manufacturing labs will be offered between 10am and 2pm.

1833 W. Southern Ave
Mesa, AZ 85202

Check out the event details here.

October 15th, 2014 – 12:30 to 6:30

AZTC Southern Arizona Tech + Business Expo: Where Technology and Manufacturing Connect

The Southern Arizona Tech + Business Expo is the regions premier showcase event for Manufacturing Month. Working in collaboration with the Southern Arizona Manufacturing Partners (SAMP), The Arizona Manufacturing Council (AMC), the RevAZ Program of the Arizona Commerce Authority, and the University of Arizona’s Tech Launch Arizona; the Expo will host informative panel discussions on strategies to grow your business faster.

The Westin La Paloma Resort
3800 E. Sunrise Drive
Tucson, AZ 85718

Check out the event details and register here.

October 30th, 2014 – 4:00 to 7:00pm

Celebrating Arizona Manufacturing

PADT is proud to host the closing celebration for Arizona Manufacturer’s Month. A variety of companies and organizations will be exhibiting their activities in the future of manufacturing. Visitors will get a chance to see some of the more advanced applications of manufacturing in the state as well as tours of the PADT facility.

Food and drinks will be provided along with great opportunities to network and get to know the community a little better.

PADT
7755 S. Research Drive
Suite 110
Tempe, AZ 85284

Register for the event here.

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ANSYS SpaceClaim and Mechanical, Plus 3D Printing to the Rescue!

p0One of the great things about working at a company like PADT is that we have the ability to solve problems from start to finish.  By start to finish, I mean: 

  1. Recognize a need
  2. Design a solution
  3. Verify the solution
  4. Manufacture the solution
  5. Deploy the solution

There are other steps that could be added such as optimization and field verification, but in simple terms those steps outline the product development process.  We do this very often at PADT, helping a wide variety of customers develop products to meet needs in the marketplace.  Most of the time, we can’t share the work we do publicly, for obvious reasons involving customer confidentiality. 

So, when we can share, it’s a good opportunity to show what our tools can do, as well as how we can utilize these tools to help our customers with the steps listed above.  We’ll look at a simple example, knowing that the same tools can help with much more complex problems.

In my case, I was faced with a problem.  We recently had our back yard pool deck resurfaced.  The problem at hand was the contractors accidently lost a plastic lid that covered a 5.5 in. hold on the deck of the pool.  This hole was for something like a basketball hoop that could be dropped into this trumpet shaped hole.  Figure 1 shows the work in progress, when the original lid was still in place.

p1Figure 1 – Original lid circled in red.

After the cleanup was done, that lid was nowhere to be found.  You would think it would be simple to find a replacement, especially in metro Phoenix where pool supply stores are abundant.  However, after visiting several supply stores as well as scouring the internet, we could not find a replacement 5.5 in. lid.  All the available lids were too big and would not work in covering this hole.  The hole without a lid is a safety concern.  In fact, our 4 year old niece managed drop a foot into the hole and ended up with a scrape.  Fortunately it wasn’t any worse than that.

Unable to find a suitable lid for purchase, I decided to pursue a 3D printed solution here at PADT.  As I’m sure you are aware, 3D printing has been portrayed all over the media in the last couple of years.  For us here at PADT, though, it has been a significant component of our business since the company’s founding in 1994.  Knowing that I could have this part printed in plastic here at PADT, I decided to go through the product development process as listed above.

So, let’s look at the various steps I followed in our product development process:

  1. Recognize a need.

In this case, it was simple.  We had a hole in the pool deck that was a safety issue.  No replacement part could be found.  A new lid was needed, one that would fit properly but also could support the weight of someone walking over it.  I decided to design a replacement part that could be 3D printed by one of the rapid prototyping technologies we have available here at PADT.

  1. Design a solution

Besides providing 3D printing services and selling 3D printers, we at PADT are a Channel Partner for ANSYS engineering simulation tools here in the Southwest.  I leveraged ANSYS, Inc.’s latest acquisition, the SpaceClaim Direct Modeler as my design tool.  SpaceClaim has been available as part of the ANSYS software suite for several years, but now SpaceClaim is officially part of the ANSYS corporate umbrella.  SpaceClaim runs within the ANSYS Workbench platform, like the ‘older’ ANSYS geometry tool, DesignModeler.  A main different between the two geometry toolsets is that DesignModeler is a history-based modeler, meaning it has a history tree that is followed to create and modify the geometry as we go along.  This works well in many circumstances but it lacks the ability to quickly and easily modify existing geometry.  SpaceClaim, on the other hand, is a direct modeler in the sense that we work on the geometry interactively, allowing us to rapidly modify geometry by ‘pulling’ on surfaces to grow, shrink, fillet, etc.  SpaceClaim is incredibly fast once we get familiar with it.

Knowing that the diameter of the hole was 5.5 inches as measured by a ruler, along with a memory of what the prior cover looked like, I turned to ANSYS SpaceClaim to come up with the geometry model.  I sketched a 2D axisymmetric cross section and swept that 360 degrees about an axis to come up with the solid model.  I very easily moved the 5.5 in diameter face inward by a small amount to allow for some clearance between the plastic part and the hole into which it needs to fit.  The geometry definition literally took just a few minutes, even though I am not yet an expert in SpaceClaim.

p2Image 2 – ANSYS SpaceClaim solid model

p3Image 3 – Cross section shown in SpaceClaim

  1. Verify the solution

I mentioned optimization as a step that could be followed.  In this simple case, I didn’t do any optimization but did perform verification that my design would meet an acceptability requirement.  I wanted to make sure that my plastic lid could support the weight of an adult standing on it.  The tool I used to perform this verification was the ANSYS Mechanical software tool.  Like SpaceClaim can, ANSYS Mechanical runs within the ANSYS Workbench environment, meaning that the geometry and subsequent stress and deflection analyses are linked.  This allows any needed changes to the geometry to quickly and easily pass from the geometry tool to the stress/deflection model, often with as little as one click of the mouse.

Getting the geometry into the Mechanical model for a finite element simulation was therefore quite simple.  Defining loads and constraints on my system was also quite simple.  What remained was to define material properties to characterize the plastic being used.  PADT’s Rapid Prototyping team informed me that the material to be used is one called Veroclear.  This material is used in one of PADT’s 3D printers, called an Objet from Statasys. 

Basic material properties for Veroclear are available on the internet, including Young’s Modulus and Yield Strength.  Poisson’s Ratio was not available so it was assumed to be 0.3.  These properties were entered into ANSYS Workbench.  For those not familiar, Young’s Modulus is a quantification of the stiffness of a material.  The Yield Strength is a measure of the how much stress a material can experience before permanent deformation occurs.  Stress, simply put, is the amount of force being carried per area in a structure.  Poisson’s Ratio relates how much a material squishes in one direction when it’s pulled in another dimension.

The loading consisted of a 210 lb. downward load on a portion of the upper surface, representing someone standing on the middle of the lid.  The constraints were frictionless supports on the outer cylindrical face as well as the bottom lip.  These constraints simulate where these two surfaces touch the hard surface of the pool deck.

p4Figure 4 – Applied Loads and Constraints

Once the model was fully setup in ANSYS Mechanical, the solution was obtained.  Lots of matrix algebra behind the scenes takes care of solving the equations needed to obtain the solution.  The resulting deflections and stresses looked to be acceptable.  I also calculated a factor of safety, relating the calculated stress in the model to the Yield Strength as described above.  A factor of safety of 2, for example, means that the predicted stress in the model is half of the Yield Strength.  The calculated factor of safety for the plastic lid is 3.17. 

p5Figure 5 – Calculated Deflections, showing maximum of 0.044 in. in center of lid.

p6Figure 6 – Equivalent Stress Distribution

p7Figure 7 – Factor of Safety Distribution

From these results we can conclude that, for the loading condition we considered:

  1. The deflections are fairly minimal
  2. The stresses are below the Yield Stress
  3. The minimum factor of safety value of 3.17 gives us confidence that under reasonable loadings, the part will not fail.

Note that this is a simplistic look at the feasibility of our design.  We didn’t consider what happens to the plastic in the hot sun, what happens if something heavy falls on the lid, etc.  Many other factors could be considered, but in this case I chose to keep it simple.

  1. Manufacture the solution

The part was printed over a weekend in an Objet printer here at PADT.  The geometry was saved as a Parasolid file in ANSYS SpaceClaim, and the Parasolid file was then provided to PADT’s Rapid Prototyping team, via the rp@padtinc.com email.  While the cost of making this particular plastic part using 3D printing is likely too high for a production run, the technology is perfect for making test articles, prototypes, molds, etc. 

p8Figure 8 – The part as printed by the Objet 3D printer (with a few water spots)

  1. Deploy the solution

In this case I only needed one lid, so I took care to make sure that the geometry was accurate before the CAD definition was sent to the 3D printer.  The proof is always in the pudding, so to speak, so it was a great comfort to see that the new plastic lid fit perfectly in the hole in the pool deck.  If this were a production part, we would probably need a vendor to mold the plastic lids in large batches to make them cost effective.

p9Figure 9 – Plastic lid in place

So, we ended up with a part the met the need, each step done very quickly using the appropriate tools in conjunction with the knowledge of how to use them.  We hope you have enjoyed this tour of the product design process, for this simple example.  Please keep PADT in mind for your product development needs.

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Congratulations to 2014 AZBioAwards Winners

BioAwards-2014-PADT- awards1 - CopyLast week, on September 17th, the Arizona Bio Technology community gathered for the 20144 AZBioAwards.  This year PADT was once again privileged to not only attend, but to again 3D Print the awards themselves.   PADT also had a both, which gave us an opportunity to talk with many of our customers who were attending.

This event honors some of the leaders in industry and is a chance for everyone involved to get together and celebrate all the progress that is made each year in this area.

PADT was also pleased to receive recognition for our 20th Anniversary from AZBIO.

You can view a press release about the whole AZBio Week, including the awards, here.

You can see pictures from the event on Facebook, here.

Here is a picture of the awards we made:

BioAwards-2014-PADT- awards2 - Copy

And here is our both with Ward Rand, Josh Heaps, and Andrew Miller interacting with a customer:

BioAwards-2014-PADT- booth5

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Default Contact Stiffness Behavior for Bonded Contact

p7It recently came to my attention that the default contact stiffness factor for bonded contact can change based on other contact regions in a model. This applies both to Mechanical as well as Mechanical APDL. If all contacts are bonded, the default contact stiffness factor is 10.0. This means that in our bonded region, the stiffness tending to hold the two sides of contact together is 10 times the underlying stiffness of the underlying solid or shell elements.

However, if there is at least one other contact region that has a type set to anything other than bonded, then the default contact stiffness for ALL contact pairs becomes 1.0. This is the default behavior as documented in the ANSYS Mechanical APDL Help, in section 3.9 of the Contact Technology Guide in the notes for Table 3.1:

“FKN = 10 for bonded. For all other, FKN = 1.0, but if bonded and other contact behavior exists, FKN = 1 for all.”

So, why should we care about this? It’s possible that if you are relying on bonded contact to simulate a connection between one part and another, the resulting stress in those parts could be different in a run with all bonded contact vs. a run with all bonded and one or more contact pairs set to a type other than bonded. The default contact stiffness is now less than it would be if all the contact regions were set to bonded.

This can occur even if the non-bonded contact is in a region of the model that is in no way connected to the bonded region of interest. Simply the presence of any non-bonded contact region results in the contact stiffness factor for all contact pairs to have a default value of 1.0 rather than the 10.0 value you might expect.

Here is an example, consisting of a simple static structural model. In this model, we have an inner column with a disk on top. There are also two blocks supporting a ring. The inner column and disk are completely separate from the blocks and ring, sharing no load path or other interaction. Initially all contact pairs are set to bonded for the contact type. All default settings are used for contact.
p1

Loading consists of a uniform temperature differential as well as a bearing load on the disk at the top. Both blocks as well as the column have their bases constrained in all degrees of freedom.
p2

After solving, this is the calculated maximum principal stress distribution in the ring. The max value is 41,382.
p3

Next, to demonstrate the behavior described above, we changed the contact type for the connection between the column and the disk from bonded to rough, all else remaining the same.
p4

After solving, we check the stresses in the ring again. The max stress in the ring has dropped from 41,283 to 15,277 as you can see in the figure below. Again, the only change that was made was in a part of the model that was in no way connected to the ring for which we are checking stresses. The change in stress is due solely to a change in contact type setting in a different part of the model. The reason the stress has decreased is that the stiffness of the bonded connection is less by a factor of 10, so the bonded region is a softer connection than it was in the original run.

p5

So, what do we as analysts need to do in light of this information? A good practice would be to manually specify the contact stiffness factor for all contact pairs. This behavior only crops up when the default values for contact stiffness factor are utilized. We can define these stiffness factors easily in ANSYS Mechanical in the details view for each contact region. Further, we need to always remember that ANSYS as well as other analytical tools are just that – tools. It’s up to us to ensure that the results of interest we are getting are not sensitive to factors we can adjust, such as mesh density, contact stiffness, weak spring stiffness, stabilization factors, etc.

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geoCUBE: Computers for Scanning

PADT just released a line of computer workstations  specifically designed for use with a variety of optical scanners: geoCUBE Scanning Workstations.

Scanning technology has come a long way.  It is relatively easy to scan a real physical part with a variety of different scanning technologies and capture the geometry for use in inspection, design, reverse engineering, or to directly replicate a part with 3D Printing.  The problem is that a good scanner produces a huge  number of data points and a standard office computer, laptop, or even most CAD workstations bog down and perhaps even crash when you try to view or manipulate that much data.  

geocube-hardware-picsWhen we ran into that exact problem here at PADT when we were doing scanning services for customers.  On a nice CAD workstation it was taking almost a whole day to clean up and process a full scan or a large part.  Our manufacturing team asked if they could power one of the CUBE Simulation Computers we use for CFD.  If you know CFD people you know they said “No, but can I also run on your box if you are not using it?”  So they went to our IT staff, the people who design CUBE systems and asked for a custom built machine for scanning.

The result was a breakthrough.  That 20 hour job was finishing in about two hours and we were able to spin the points and the resulting triangle file around on the screen in real time. We liked it so much we decided to come up with four systems spanning the needs of scanning users, and offer them along with the scanner we sell, or to anyone that might need one.

Below is a screen shot of the table showing the four systems, from a basic small box that you can use to drive your scanner, to the power system that we use.  You can download the brochure here, or visit the web page here

geoCUBE-Spec-Table-Screen-Shot

As always, feel free to contact us to get more information and see how we can help you find the right scanner and the perfect computer to go with it.

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