Seminar: Additive Manufacturing & the Honeywell Global Initiative

honeywell-speachDonald Godfrey, Honeywell Engineering Fellow for Additive Manufacturing will be presenting a seminar at Arizona State University on the status of metal Additive Manufacturing (AM) within the company worldwide.  This live event, being held at the ASU Polytechnic Campus in Mesa, Arizona, will be a fantastic opportunity to learn how this exciting technology is used in the real world to change the way aerospace parts are designed and made.

Download the PDF:  Honewell-additive-asu-1, to learn more.

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GCOI 2015 – Celebrating Arizona’s Technology Community

gcoi_iconFor those of us that are part of the Arizona Technology community, the official kickoff of holiday and end of year celebrations is the Governor’s Celebration of Innovation, or GCOI.  A who’s who of key people from startups to large aerospace firms gather at the convention center to recognize students, academicians, companies, and individuals who have had a significant impact on the State’s high tech industries.  This is always a special evening for PADT because many of the attendees, and usually a few of the award winners, are our customers.

In fact, for 2015 we are proud to congratulate the following long time PADT customers who were recognized last night:

  • Medtronic Tempe Campus for Innovator of the Year, Large Company
  • Raytheon Missile Systems for winning the Pioneering Award
  • ASU’s Michael Crow, the OneNeck IT Services People’s Choice Lifetime Achievement Award winner (ASU is a large PADT customer… so we feel Dr. Crow is our customer as well.)

You can find a full list of winners and some great pictures  from the event in Tishin Donkersley’s article at AZ Tech Beat.

This fantastic event is put on by the Arizona Technology Council and the Arizona Commerce Authority.  For those that were there: Mac & Cheese bar FTW.


About the Awards

As in past years, PADT was honored to be able to fabricate the awards that were handed out. This year we used the overall design for the event, created by Atom, as our starting point. We used our Stratasys FDM printers to make the stair steps and “tech guy silhouette” The graphics are then printed on large stickers that are adhered to the back of an Arizona’ish shaped piece of plexiglass.


The PADT Booth

This year we decided to not bring a 3D Printer and instead focus on parts made on a wider variety of printers. The hit for visitors were the metal parts that were made on ConceptLaser Direct Laser Melting systems.  In addition we got to talk about the great work that our product development team did for GlobalStar on the Spot devices and Orthosensor for their intelligent orthopedic sensors. We even had a few simulation people come by to talk ANSYS.


Hopefully you had a chance to talk with Andrew Miller, Kathryn Pesta, or Mario Vargas. If you missed us and want to know more about PADT, what we do, or the Arizona Technology Community, reach out and we will be happy to chat.


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Be a Pinball Wizard with Contact Regions in ANSYS Mechanical


A pinball machine based on The Who’s Tommy

I had a very cool music teacher back in 6th or 7th grade in the 1970’s in upstate New York.  Today we’d probably say she was eclectic.  In that class we listened to and discussed fairly recent songs in addition to general music studies.  Two songs I remember in particular are ‘Hurdy Gurdy Man’ by Donovan and ‘Pinball Wizard’ by The Who.  If you’re not familiar with Pinball Wizard, it’s from The Who’s rock opera Tommy, and is about a deaf, mute, blind young man who happens to be adept at the game of pinball.  Yes, he is a Pinball Wizard.  This sing popped into my head recently when we had some customer questions here at PADT regarding the pinball region concept as it pertains to ANSYS contact regions.

I’m not sure if the developers at ANSYS, Inc. had this song in mind when they came up with the nomenclature for the 17X (latest and greatest) series of contact elements in ANSYS, but regardless, you too can be a pinball wizard when it comes to understanding contact elements in ANSYS Mechanical and MAPDL.

Fans of this blog may remember one of my prior posts on contact regions in ANSYS that also had a musical theme (bringing to mind Peter Gabriel’s song “I Have the Touch”):

In this current entry we will go more in depth on the pinball region, also known as the pinball radius.  The pinball region is involved with the distance from contact element to target element in a given contact region.  Outside the pinball region, ANSYS doesn’t bother to check to see if the elements on opposite sides of the contact region are touching or not.  The program assumes they are far away from each other and doesn’t worry about any additional calculations for the most part.

Here is an illustration.  The gray elements on the left represent the contact body and the red elements on the right represent the target body (assuming asymmetric contact).  Target elements outside the pinball radius will not be checked for contact.  The contact and target elements actually ‘coat’ the underlying solid elements so they are shown as dashed lines slightly offset from the solid elements for the sake of visibility.  Here the pinball radius is displayed as a dashed blue circle, centered on the contact elements, with a radius of 2X the depth of the underlying solid elements.


So, outside the pinball region, we know ANSYS doesn’t check to see if the contact and target are actually in contact.  It just assumes they are far away and not in contact.  What about what happens if the contact and target are inside the pinball region?  The answer to that question depends on which contact type we have selected.

For frictionless contact (aka standard contact in MAPDL) and frictional contact, the program will then check to see if the contact and target are truly touching.  If they are touching, the program will check to see if they are sliding or possibly separating.  If they are touching and penetrating, the program will check to see if the penetration exceeds the allowable amount and will make adjustments, etc.  In other words, for frictionless and frictional contact, if the contact and target elements are close enough to be inside the pinball region, the program will make all sorts of checks and adjustments to make sure the contact behavior is adequately captured.

The other scenario is for bonded and no separation contact.  With these contact types, the program’s behavior when the contact and target elements are within the pinball region is different.  For these types, as long as the contact and target are close enough to be within the pinball region, the program considers the contact region to be closed.  So, for bonded and no separation, your contact and target elements do not need to be line on line touching in order for contact to be recognized.  The contact and target pairs just need to be inside the pinball region.  This can be good, in that it allows for some ‘slop’ in the geometry to be automatically ignored, but it also can have a downside if we have a curved surface touching a flat surface for example.  In that case, more of the curved surface may be considered in contact than would be the case if the pinball region was smaller.  This effect is shown in the image below.  Reducing the pinball radius to an appropriate smaller amount would be the fix for eliminating this ‘overconstraint’ if desired.


There is a default value for the pinball region/radius.  It can be changed if needed.  We’ll add more details in a moment.  First, why is it called the “pinball” region?  I like to think it’s because when it’s visualized in the Mechanical window, it looks like a blue pinball from an actual pinball arcade game, but I’ll admit that the ANSYS terminology may predate the Mechanical interface.  The image below shows what I mean.  The blue balls are the different pinball radii for different contact regions.



Note that you don’t see the pinball region displayed as shown in the above image unless you have manually changed the pinball size in Mechanical.  The pinball region can be changed in the Mechanical window in the details view for each contact region by changing Pinball Region from Program Controlled to Radius, like this:


In MAPDL, the pinball radius value can be changed by defining or editing the real constant labeled PINB.

By now you’re probably wondering what is the default value for the pinball radius?  The good news is that it is intelligently decided by the program for each contact region.  The default is always a scale factor on the depth of the underlying elements of each contact region.  In the first pinball region image shown near the beginning of this article, the example plot shows the pinball region/radius as two times the depth of the underlying elements.

The table below summarizes the default pinball radius values for most circumstances for 2D and 3D solid element models.  More detailed information is available in the ANSYS Help.

Default Pinball Radius ValuesLarge Deflection Off
Large Deflection On
Frictionless and Frictional1* Underlying Element Depth2*Underlying Element Depth
Bonded and No Seperation0.25*Underlying Element Depth0.5*Underlying Element Depth
Rigid-Flexible Contact: Typically the Default Values are Doubled

Summing it all up:  we have seen how the default values are calculated and also how to change them.  We have seen what they look like as blue balls in a plot of contact regions in Mechanical if the pinball radius has been explicitly defined.  We also discussed what the pinball radius does and how it’s different for frictionless/frictional contact and bonded/no separation contact.

You should be well on your way to becoming a pinball wizard at this point.

Does performing simulation in ANSYS make you think of certain songs, or are there songs you like to listen to while working away on your simulations an addition to The Who’s “Pinball Wizard” and Peter Gabriel’s “I Have the Touch”?  If so, we’d love to hear about your song preferences in the comments below.

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Video: Automated Test Fixture for Biopsy Device

biobsy-test-fixture-1How do you figure out when and why a product is failing?  When the failure is due to repetitive operation the only practical way is to build a machine that operates the product over and over again. Designing, building, and running this type of device is one of the many services that PADT offers its customers.

The video below is an example of how PADT’s Medical Device team developed an automated text fixture for a customer that needed to understand the failure mechanisms of a biopsy device. The fixture was designed to operate the device, repeating field operations, and capture behavior over time with the goal of capture which components failed, the nature of each failure, and the nature of each failure.

The apparatus repeats four operations that constitute one operation of the device. Video is used with a counter to determine when a failure occurred and how. The project brought together test, controls, and mechanical design engineers. It also utilized PADT’s in-house 3D Printing and machining capability.

This is also a perfect example of how a customer can hand over an entire project that they need done, but don’t have the resources to do in-house. PADT’s team created the test specification, designed the hardware, conducted the tests, and delivered actionable information to the customer.

If you have a project you do not have the resources to complete in-house, consider having our engineers take a look at it to see how we can help.

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Programming a Simple Polygon Editor

polygon-editor-icon-1Part of my job at PADT is writing custom software for our various clients.  We focus primarily on developing technical software for the engineering community, with a particular emphasis on tools that integrate with the ANSYS suite of simulation tools.  Frankly, writing software is my favorite thing to do at PADT, simply because software development is all about problem solving.

This morning I got to work on a fairly simple feature of a much larger tool that I am currently developing.  The feature I’m working on involves graphically editing polygons.  Why, you ask am I doing this?  Well, that I can’t say, but nonetheless I can share a particularly interesting problem (to me at least) that I got to take a swing at solving.  The problem is this:

When a user is editing a node in the polygon by dragging it around on the screen, how do you handle the case when they drop it on an existing node?

Consider this polygon I sketched out in a prototype of the tool.


What should happen if the user drags this node over on top of that node:polygon-editor-f02

Well, I think the most logical thing to do is that you merge the two nodes together.  Implementing that is pretty easy.  The slightly harder question is what to do with the remaining structure of the polygon?  For my use case, polygons have to be manifold in that no vertex is connected to more than two edges. (The polygons can be open and thus have two end vertices connected to only one edge.)  So, what part do you delete?  Well, my solution is that you delete the “smaller” part, where “smaller” is defined as the part that has the fewest nodes.  So, for example, this is what my polygon looks like after the “drop”

polygon-editor-f03Conceptually, this sounds pretty simple, but how do you do it programmatically?  To give some background, note that the nodes in my polygon class are stored in a simple, ordered C++ std::list<>.

Now, I use a std::list<> simply because I know I’m going to be inserting and deleting nodes at random places.  Linked lists are great for that, and for rendering, I have to walk the whole list anyway, so there’s no performance hit there.  Graphically, my data structure looks
something like this:polygon-editor-f04Pretty simple.  For a closed polygon, my class maintains a flag and simply draws an edge from the last node to the first node.

The rub comes when you start to realize that there are tons of different ways a user might try to merge nodes together in either an open or closed polygon.  I’ve illustrated a few below along with what nodes would need to be merged in the corresponding data structure.  In the data structure pictures, the red node is the target (the node on which the user will be dropping) and the green node is the one they are manipulating (the source node).

Here is one example:


Here is another example:


Finally, here is one more:polygon-editor-f08polygon-editor-f09

In all these examples, we have different “cases” that we need to handle.  For instance, in the first example the portion of the data structure we want to keep is the stuff between the source and target nodes.  So, the stuff on the “ends” of the list needs to be deleted.  In the middle case, we just need to merge the source and target together.  Finally, in the last case, the nodes between the source and target need to be deleted, whereas the stuff at the “ends” of the list need to be kept.

This simple type of problem causes shivers in many programmers, and I’ll admit, I was nervous at first that this problem was going to lead to a solution that handled each individual case respectively.  Nothing in all of programming is more hideous than that.  So, there has to be a simple way to figure out what part of the list to keep, and what part of the list to throw away.

Now, I’m sure this problem has been solved numerous times before, but I wanted to take a shot at it without googling.  (I still haven’t googled, yet… so if this is similar to any other approach, they get the credit and I just reinvented the wheel…)  I remember a long time ago listening to a C++ programmer espouse the wonders of the standard library’s algorithm section.  I vaguely remember him droning on about how wonderful the std::rotate algorithm is.  At the time, I didn’t see what all the fuss was about.  Now, I’m right there with him.  std::rotate is pretty awesome!

std::rotate is a simple algorithm.  Essentially what it does is it takes the first element in a list, pops it off the list and moves it to the rear of the list.  Everything else in the list shifts up one spot.  This is called a left rotate, because you can imagine the items in the list rotating to the left until they get to the front of the line, at which point they fall off and are put back on the end of the list.  (Using reverse iterators you can effectively perform a right rotate as well.)  So, how can we take advantage of this to simplify figuring out what needs to be deleted from our list of nodes?

Well, the answer is remarkably simple.  Once we locate the source and target nodes in the list, regardless of their relative position with respect to one another or to the ends of the list, we simply left rotate the list until the target becomes the head of the list.  That is, if we start with this:polygon-editor-f10We left rotate until we have this:polygon-editor-f11That’s great, but what does that buy us?  Well, now that one of the participating nodes is at the head of the list, our problem is much simpler because all of the nodes that we need to delete are now at either end of the list.  The only question left to answer is which end of the list do we trim off?  The answer to that question is trivial.  We simply trim off the shorter end of the list with respect to the source node (the green node in the diagram). The “lengths” of the two lists are defined as follows.  For the head section, it’s the number of nodes up to, but not including the source. (This section obviously includes the target node)  For the tail, it’s the number of nodes from the source to the end, including the source.  (This section includes the source node).  Since we define the two sections this way we are guaranteed to delete either the source or the target, but not both.  Its fine to delete either one of them, because at this point we’ve deemed the geometrically coincident, but we must not accidentally delete both!!

In the example just given, after the rotate, we would delete the head of the list.  However, let’s take a look at our first example.  Here is the original list:

polygon-editor-f12Here is the rotated list:polygon-editor-f13So, in this case, the “end” of the list (including the source) is the shortest.  If it is a tie, then it doesn’t matter, just pick one.  Interestingly enough, if the two nodes are adjacent in the original list, then the rotated list will look like either this:polygon-editor-f14 Or this, if the source is “before” the target in the original list:polygon-editor-f15In either case, the algorithm works unchanged, and we only delete one node.  It’s beautiful! (At least in my opinion…)  Modern C++ makes this type of code really clean and easy to write.  Here is the entire thing, including the search to located geometrically adjacent nodes as well as the merge. The standard library algorithms really help out!

// Search lambda function for looking for any other node in the list that is
// coindicent to this node, except this node.
auto searchAdjacentFun = [this, pNode](const NodeListTool::AdjustNodePtrT &amp;pOtherNode)-&gt;bool
if (pNode-&gt;tag() == pOtherNode-&gt;tag()) return false;
return (QVector2D(pNode-&gt;pos() - pOtherNode-&gt;pos()).length() &lt; m_snapTolerance); }; auto targetLoc = std::find_if(m_nodes.begin(), m_nodes.end(), searchAdjacentFun); // If we don't find an adjacent node within the tolerance, then we can't merge if (targetLoc == m_nodes.end()) { return false; } // Tidy things up so that the source has exactly the same position as the target pNode-&gt;setPos((*targetLoc)-&gt;pos());
// Begin the merge by left rotating the target so that it is at the
// beginning of the list
std::rotate(m_nodes.begin(), targetLoc, m_nodes.end());
// Find this node in the list
auto searchThis = [this, pNode](const NodeListTool::AdjustNodePtrT &amp;pOtherNode)-&gt;bool
return (pNode-&gt;tag() == pOtherNode-&gt;tag());
auto sourceLoc = std::find_if(m_nodes.begin(), m_nodes.end(), searchThis);
// Now, figure out which nodes we are going to delete.
auto distToBeg = std::distance(m_nodes.begin(), sourceLoc);
auto distToEnd = std::distance(sourceLoc, m_nodes.end());
if (distToBeg &lt; distToEnd) { // If our source is closer to the beginning (which is the target) // than it is to the end of the list, then we need to delete // the nodes at the front of the list m_nodes.erase(m_nodes.begin(), sourceLoc); } else { // Otherwise, delete the nodes at the end of the list m_nodes.erase(sourceLoc, m_nodes.end()); } // Now, see if we still have more than 2 vertices if (m_nodes.size() &gt; 2) {
m_bClosed = true;
else {
m_bClosed = false;
return true;
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2015 PADT Pumpkin Fest and Launch

padt-pumpkin-lunch-1Every year around the end of October PADT has our holiday season kick-off event, our Pumpkin Fest and Launch.  This year we also added in a company meeting, killing three birds with one pumpkin.

The weather was fantastic, and we all enjoyed sitting outside in the sun under a clear blue sky.  Our pumpkin catapult, recently improved, was then rolled out for some pumpkin chunkin’ fun.

Thanks to the folks at Tech Shop Chandler we had a redesigned basket for the pumpkins to go in. Their industrial sewing machine was a perfect tool to make something strong enough.  Her are some picture below that I took with my phone, we will add video next week.

Manoj M won on distance, and Jeff McK took the prize for accuracy.


The PADT Pumpkin cataPult ready to go.


Ted shows good form while striving for accuracy


The only change to this years design was a better basket made with industrial fabric on an industrial sewing machine from Tech Shop

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7 Reasons why ANSYS AIM Will Change the Way Simulation is Done

ANSYS-AIM-Icon1When ANSYS, Inc. released their ANSYS AIM product they didn’t just introduce a better way to do simulation, they introduced a tool that will change the way we all do simulation.  A bold statement, but after PADT has used the tool here, and worked with customers who are using it, we feel confident that this is a software package will drive that level of change.   It enables the type of change that will drive down schedule time and cost for product development, and allow companies to use simulation more effectively to drive their product development towards better performance and robustness.

It’s Time for a Productivity Increase

AIM-7-old-modelIf you have been doing simulation as long as I have (29 years for me) you have heard it before. And sometimes it was true.  GUI’s on solvers was the first big change I saw. Then came robust 3D tetrahedral meshing, which we coasted on for a while until fully associative and parametric CAD connections made another giant step forward in productivity and simulation accuracy. Then more recently, robust CFD meshing of dirty geometry. And of course HPC improvements on the solver side.

That was then.  Right now everyone is happily working away in their tool of choice, simulating their physics of choice.  ANSYS Mechanical for structural, ANSYS Fluent for fluids, and maybe ANSYS HFSS for electromagnetics. Insert your tool of choice, it doesn’t really matter. They are all best-in-breed advanced tools for doing a certain type of physical simulation.  Most users are actually pretty happy. But if you talk to their managers or methods engineers, you find less happiness. Why? They want more engineers to have access to these great tools and they also want people to be working together more with less specialization.

Putting it all Together in One Place

AIM-7-valve2-multiphysicsANSYS AIM is, among many other things, an answer to this need.  Instead of one new way of doing something or a new breakthrough feature, it is more of a product that puts everything together to deliver a step change in productivity. It is built on top of these same world class best-in-bread solvers. But from the ground up it is an environment that enables productivity, processes, ease-of-use, collaboration, and automation. All in one tool, with one interface.

Changing the Way Simulation is Done

Before we list where we see things changing, let’s repeat that list of what AIM brings to the table, because those key deliverables in the software are what are driving the change:

  • IAIM-7-pipe-setupmproved Productivity
  • Standardized Processes
  • True Ease-of-Use
  • Inherent Collaboration
  • Intuitive Automation
  • Single Interface

Each of these on their own would be good, but together, they allow a fundamental shift in how a simulation tool can be used. And here are the seven way we predict you will be doing things differently.

1) Standardized processes across an organization

The workflow in ANSYS AIM is process oriented from the beginning, which is a key step in standardizing processes.  This is amplified by tools that allow users, not just programmers, to create templates, capturing the preferred steps for a given type of simulation.  Others have tried this in the past, but the workflows were either too rigid or not able to capture complex simulations.  This experience was used to make sure the same thing does not happen in ANSYS AIM.

2) No more “good enough” simulation done by Design Engineers

Ease of use and training issue has kept robust simulation tools out of the hands of design engineers.  Programs for that group of users have usually been so watered down or lack so much functionality, that they simply deliver a quick answer. The math is the same, but it is not as detailed or accurate.  ANSYS AIM solves this by give the design engineer a tool they can pick up and use, but that also gives them access to the most capable solvers on the market.

3) Multiphysics by one user

Multiphysics simulation often involves the use of multiple simulation tools.  Say a CFD Solver and a Thermal Solver. The problem is that very few users have the time to learn two or more tools, and to learn how to hook them together. So some Multiphysics is done with several experts working together, some in tools that do multiple physics, but none well, or by a rare expert that has multi-tool expertise.  Because ANSYS AIM is a Multiphysics tool from the ground up, built on high-power physics solvers, the limitations go away and almost any engineer can now do Multiphysics simulation.

AIM-7-study4) True collaboration

The issues discussed above about Multiphysics requiring multiple users in most tools, also inhibit true collaboration. Using one user’s model in one tool is difficult when another user has another tool. Collaboration is difficult when so much is different in processes as well.  The workflow-driven approach in ANSYS AIM lends itself to collaboration, and the consistent look-and-feel makes it happen.

5) Enables use when you need it

This is a huge one.  Many engineers do not use simulation tools because they are occasional users.  They feel that the time required to re-familiarize themselves with their tools is longer than it takes to do the simulation. The combination of features unique to ANSYS AIM deal with this in an effective manner, making accurate simulation something a user can pick up when they need it, use it to drive their design, and move on to the next task.

6) Stepping away from CAD embedded Simulation

The growth of CAD embedded simulation tools, programs that are built into a CAD product, has been driven by the need to tightly integrate with geometry and provide ease of use for the users who only occasionally need to do simulation. Although the geometry integration was solved years ago, the ease-of-use and process control needed is only now becoming available in a dedicated simulation tool with ANSYS AIM.

7) A Return to home-grown automation for simulation

AIM-7-scriptIf you have been doing simulation since the 80’s like I have, you probably remember a day when every company had scripts and tools they used to automate their simulation process. They were extremely powerful and delivered huge productivity gains. But as tools got more powerful and user interfaces became more mature, the ability to create your own automation tools faded.  You needed to be a programmer. ANSYS AIM brings this back with recording and scripting for every feature in the tool, with a common and easy to use language, Python.

How does this Impact Me and or my Company?

It is kind of fun to play prognosticator and try and figure out how a revolutionary advance in our industry is going to impact that industry. But in the end it really does not matter unless the changes improve the product development process. We feel pretty strongly that it does.  Because of the changes in how simulation is done, brought about by ANSYS AIM, we feel that more companies will use simulation to drive their product development, more users within a company will have access to those tools, and the impact of simulation will be greater.


To fully grasp the impact you need to step back and ponder why you do simulation.  The fast cars and crazy parties are just gravy. The core reason is to quickly and effectively test your designs.  By using virtual testing, you can explore how your product behaves early in the design process and answer those questions that always come up.  The sooner, faster, and more accurately you answer those questions, the lower the cost of your product development and the better your final product.

Along comes a product like ANSYS AIM.  It is designed by the largest simulation software company in the world to give the users of today and tomorrow access to the power they need. It enables that “sooner, faster, and more accurately” by allowing us to change, for the better, the way we do virtual testing.

The best way to see this for yourself is to explore ANSYS AIM.  Sign up for our AIM Resource Kit here or contact us and we will be more than happy to show it to you.


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Video Tips: Fluid Volume Extraction

This video shows a really quick and easy way to extract a fluid domain from a structural model without having to do any Boolean subtract operations.

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Making Old Desks New at PADT

  • whiteboard-desks-icon1It has been a long time since I have written any articles. I thought to get me back into the flow of writing I would share a recent fun project that I completed at work where I was able reuse and re-purpose abandoned 20 year-old office desks. The issue started out a frustration related to note taking and I wanted something better. What is my frustration, how did it start? It was started by simple pet peeve of my own. I do not like using paper to jot down quick ideas, thoughts or a to-do on! I write numerous quick notes down during my day at work.

    Some examples of my daily office dilemma:

  • Rapid fire phone calls that can bounce my phone off the desk.
  • I just have to jot something down less than a single sentence down.
  • A conference call occurs I need to capture a couple quick thoughts down because I am such a great active listener and don’t want to interrupt.
  • Even sketching out a quick design for a new CUBE HPC cluster or workstation.

My whys may not be your whys and I feel like it is a time & resource waste! You might too especially when I the thoughts go something like this.

Should I:

  • Use a new piece of paper to write quick notes on? Nope
  • Find the special square colored sticky things? Nope
  • Dig through the paper recycling bin and get strange looks from my co-workers? Nope
  • Cut my own square colored sticky note things? Nope
  • I can’t seem to find a pen, open a brand new box of pens? Nope
  • Take your notes on the electronic device of your choosing, okay which one phone, laptop, and/or tablet or how about use that conference room computer? Then I end up having quick notes and scribbles EVERYWHERE!
  • Sigh…

I hope those points made you laugh and frames a picture that I was not in my comfort zone. I knew what I wanted. I had used the same note taking process for years. Probably every day I would use my two whiteboards to write quick notes on. Whiteboards worked for me, I loved my whiteboards and life was good. What happened and where the frustration occurred was that I had four office desk moves over a time span of a year at PADT, Inc. Guess what happened the new office areas did not have whiteboards in them!

Here is a picture of a bunch of abandoned desks here at PADT, Inc. I walk past desks like these every day. Then during the office moving a thought occurred to me that maybe I could use paste or mat whiteboard type surface to them and make a whiteboard type desk?

whiteboard-desks-01I figured that someone had already thought of the idea already and remembered about a business trip that I took to California this past year. I remember walking through the insides of startup lab office building. You could feel the venture capital money pulsing through the office walls. This office building environment was sophisticated and exciting. What did I notice? I am sure you can think of some good examples. Haha, but what I found fascinating was groups of people collaborating with dry-erase markers in hand and notes scribbled over entire sections of walls. On huge conference room tables I even saw that large sections of glass walls where used. Boom! I had my solution.

I did my research and this is what I used.

The primer & the solution:

The cost:

  • About $50 and a few hours of time
    • One package of the dry erase can do about 3-4 coats for a 30 sq ft area, or about two thick coast on two desks.

The steps:

  1. Lightly sand the top until smooth.
  2. Clean the top of the desk.
  3. Mask the ends of the table
  4. Apply coat of primer
  5. Apply the solution
    1. After the third or fourth coat is on, wait 3 days for use.

The results:

whiteboard-desks-02 whiteboard-desks-03 whiteboard-desks-04

Do It!

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Free ANSYS AIM Resource Kit — Expert Advice, Insights and Best Practices for Multiphysics Simulation

ANSYS-AIM-Icon1We have been talking a lot about ANSYS AIM lately.  Mostly because we really like ANSYS AIM and we think a large number of engineers out there need to know more about it and understand it’s advantages.  And the way we do that is through blog posts, emails, seminars, and training sessions.  A new tool that we have started using are “Resource and Productivity Kits,” collections of information that users can download.

Earlier in the year we introduced several kits, including ANSYS Structural, ANSYS Fluids, and ANSYS ElectroMechanical.  Now we are pleased to offer up a collection of useful information on ANSYS AIM.  This kit includes:

  • “Getting to know ANSYS AIM,” a video by PADT application engineer Manoj Mahendran
  • “What I like about ANSYS AIM,” a video featuring insights on the tool
  • Six ANSYS AIM demonstration videos, including simulations and a custom template demonstration
  • Five slide decks that provide an overview of ANSYS AIM and describe its new features
  • An exclusive whitepaper on effectively training product development engineers in simulation.

You can download the kit here.

If you need more info, view the ANSYS AIM Overview video or read about it on our ANSYS AIM page.

Watch this blog for more useful content on AIM in the future.


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To Use Large Deflection or Not, That Is the Question

Hamlet-Large-DeflectionIt seems like I’ve been explaining large deflection effects a lot recently. Between co-teaching an engineering class at nearby Arizona State University and also having a couple of customer issues regarding the concept, large deflection in structural analyses has been on my mind.

Before I explain any further, the thing you should note if you are an ANSYS Mechanical simulation user is this: If you don’t know if you need large deflection or not, you should turn it on. There is really no way to know for certain if it’s needed or not unless you perform a comparison study with and without it.

So, what are large deflection effects? In simple terms the inclusion of large deflection means that ANSYS accounts for changes in stiffness due to changes in shape of the parts you are simulating. The classic case to consider is the loaded fishing rod.

In its undeflected state, the fishing rod is very flexible at the tip. With a heavy fish on the end of the line, the rod deflects downward and it is then easy to observe that the stiffness of the rod has increased. In other words, when the rod is lightly loaded, a small amount of force will cause a certain downward deflection at the top. When the rod is heavily loaded however, a much larger amount of force will be needed to cause the tip to deflect downward by the same amount.

This change in the force amount required to achieve the same change in displacement implies that we do not have a linear relationship between force and displacement.
Consider Hooke’s law, also known as the spring equation:

F = Kx

Where F is the force applied, K is the stiffness of the structure, and x is the deflection. In a linear system, doubling the force results in double the displacement. In our fishing rod case, though, we have a nonlinear system. We might need to triple the force to double the displacement, depending on how much the rod is loaded relative to its size and other properties, and then to double the displacement again we might need to apply four times that force, just using numbers out of my head as examples.


So, in the case of the fishing rod, Hooke’s law in a linear form does not apply. In order to capture the nonlinear effect we need a way for the stiffness to change as the shape of the rod changes. In our finite element solution in ANSYS, it means that we want to recalculate the stiffness as the structure deflects.

This recalculation of the stiffness as the structure deflects is activated by turning on large deflection effects. Without large deflection turned on, we are constrained to using the linear equation, and no matter how much the structure deflects we are still using the original stiffness.

So, why not just have large deflection on by default and use it all the time? My understanding is that since large deflection adds computation expense to have it on, it’s off by default. It’s the same as for a lot of advanced usage, such as frictionless or frictional contact vs. the default bonded (simpler) behavior. In other words, turning on large deflection will trigger a nonlinear solution, meaning multiple passes through the solver using the Newton Raphson method instead of the single pass needed for a linear problem.

Here is an example of a simplified fishing rod. The image shows the undeflected rod (top), which is held fixed on the left side and has a downward force load applied on the right end. The bottom image shows the final deflected shape, with large deflection effects included. The deflection at the tip in this case is 34 inches.


In comparison running the same load with large deflection turned off resulted in a tip deflection of 40 inches. Thus, the calculated tip deflection is 15% less with large deflection turned on, since we are now accounting for change in stiffness with change in shape as the rod deflects.

Below we have a force (horizontal axis) vs. deflection (vertical axis) plot for a nonlinear simulation of a fishing rod with large deflection turned on. The fact that the curve is not a straight line confirms that this is a nonlinear problem, with the stiffness (slope of the curve) not constant. We can also see that as the force gets higher, the slope of the curve is more horizontal, meaning that more force is needed for each incremental amount of displacement. This matches our observations of the fishing rod behavior.


So, getting back to our original point, it’s often the case that we don’t know if we need to include large deflection effects or not. When in doubt, run cases with and without. If you don’t see a change in your key results, you can probably do without large deflection.

Here is an example using an idealized compressor vane. In this case, the deflections and stresses with and without large deflection effects are nearly the same (the stress difference is about 0.2%).

Large Deflection On:blade_large_defl

Small Deflection:blade_small_defl

Bottom line: when in doubt, try it out, with and without large deflection. In ANSYS Mechanical, Large Deflection effects are turned on or off in the details of the Analysis Settings branch.

It’s worth noting that turning on large deflection in ANSYS actually activates four different behaviors, known as large deflection which include large rotation, large strain, stress stiffening, and spin softening. All of these involve change in stiffness due to deformation in one way or another.

If you like this kind of info, or find it useful, we cover topics like this in our training classes. For more info, check out our training pages at

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3D Printing – A 2D Explainer from Shapeways

shapeways_3d_printing_headerWhat is this 3D Printing anyway?  It doesn’t take long for someone new to the technology to see the wide range of applications and implications it brings to the table.  But what how does it actually work. Our friends at Shapeways have put together a great infographic that explains things well.

Take a look and share:


If you scrolled down this far, you may be asking, “Why is PADT sharing Shapeways material? Are they not competitors?”  Well, to be honest, we recommend Shapeways to people all the time. Our Additive Manufacturing business is about producing engineering prototypes, tooling, and end-use products for manufacturing companies. When a hobbiest or artist comes to ask us for a prototype, we often recommend that they go visit Shapeways.

We also recommend that people who are interested in all the non-engineering applications for 3D Printing check out their marketplace. The things that people have come up with is just amazing and shows the unbounded potential of this technology.

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Presentation: Leveraging Simulation for Product Development of IoT Devices



Yours truly going over the impact of Simulation on IoT Product Development

The local SEMI chapter here in Arizona held a breakfast meeting on Monetizing Internet of Things (IoT) and PADT was pleased to be one of the presenters. Always a smart group, this was a chance to sit with people making the sensors, chips, and software that enable the IoT and dig deep in to where things are and where they need to be.

The event was hosted by one of our favorite customers, and neighbor right across the street, Freescale Semiconductor.  Speakers included IoT experts from Freescale, Intel, Medtronics, ASU, and SEMICO Research.

Not surprisingly I talked about how Simulation can play a successful role in product development of IoT devices.

You can download a copy of the presentation here: PADT-SEMI-IOT-Simulation-1.pdf

UPDATE (11/9/2015): Great write-up by Don Dingee on this event in the SemiWiki. Click here to read it. It includes a great summary of the other speakers.

You can also see more details on how people use Simulation for this application on the ANSYS, Inc. website here.  We also like this video from ANSYS that shows some great applications and how ANSYS is used with them:

A couple of common themes resonated across the speakers:

  1. Price and size need to come down on the chips used in IoT (this was a semiconductor group, so this is a big part of their focus)
  2. Lowering power usage and increasing power density in batteries is a key driver
  3. The biggest issue in IoT is privacy and security. Keeping your data private and keeping people from hacking in to IoT devices.
  4. Another big problem is dealing with all the data collected by IoT devices. How to make it useful and how to store it all.  One answer is reducing the data on the device, another is only keeping track of what changes.
  5. It is early, standards are needed but they are still forming.

If you look at this list, the first two problems are addressable with simulation:


PADT has a growing amount of experience with helping customers simulate and design IoT devices as well as the chips, sensors, and antenna that go in to IoT devices.  To learn more, shoot us an email at or call 480.813.4884.


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Manufacturing Open House Highlights – October 2015

padt-mfg-openhouse-2015-1Here at PADT we help people who make products, stuff that gets manufactured.  So we focused our open house yesterday on advanced manufacturing and invited the community to come out and network, learn, and share.  Even though it was a busy week for technology events in Arizona, we had a great turnout on a surprisingly cloudy Wednesday evening.

October is Manufacturing month and this open house was part of the Arizona Commerce Authority’s coordinated events to highlight manufacturing in Arizona.   You can learn more about other events in the state here.

This event was a bit more casual and less structured then past PADT open houses, letting attendees spend more time one-on-one with various experts and dig deep in to technologies like metal 3D Printing, urethane casting, topological optimization, and scanning.

What struck all of us here was the keen interest in and knowledge about the various tools we were showing across a wide range of attendees.  From students with home built 3D Printers to managers from local aerospace companies that are on the forefront of Additive Manufacturing, the questions that were asks and comments that were made with insightful and show a transition of this technology from hype to real world application.

Below are some more quick snapshot taken during the event.

A big thanks to everyone who made it out and we hope to see more of you next time. If you have any questions about the application of advanced manufacturing technologies to your products, don’t hesitate to reach out to us at or 480.813.4884.  As always, visit to learn more.


PADT’s Dr. Dhruv Bhate explains the latest developments in metal Additive Manufacturing.


PADT’s Director of Engineering, Rob Rowan, discusses how PADT Medical has helped companies turn their medical device ideas into products.






Ademola Falade, PADT's scanning expert, describes how blue light scanning has changed how we capture geometry of existing parts.

Ademola Falade, PADT’s scanning expert, describes how blue light scanning has changed how we capture geometry of existing parts.

PADT's Seminar Room was packed with people talking to PADT's expert engineering staff.

PADT’s Seminar Room was packed with people talking to PADT’s expert engineering staff.



PADT’s 3D Printing Demo room was the place to hang and discuss different ways to use 3D Printing.


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Free Training and Evaluation for ANSYS AIM

AIM_City_CFDPADT is hosting a series of free training classes to introduce users to ANSYS AIM.  We have pasted the invitation below.  You can register here.  We are very excited about this new tool from ANSYS, Inc. and are eager to share it with everyone. Look for more AIM information on this blog in the near future.

Free Training and Evaluation for ANSYS® AIM™.
Register Today – Seats Are Limited.

Discover how to design your next product
better… and faster


ANSYS AIM: Integrated Multiphysics Simulation Environment
for All Engineers


Free Training and Evaluation for ANSYS® AIM™ – An Integrated Multi-physics Simulation Environment for All Engineers

As a special offer, PADT Inc. is offering FREE “Jump Start” training and hands-on evaluation for ANSYS® AIM™. Design engineers, method engineers and managers seeking to learn the latest simulation software, boost adoption and usability for the occasional user, or extend their existing CAD-based tool’s limited functionality will benefit from this no-obligation course.

Register Today – Seats are limited and will be filled on a first-come, first-served basis. On completion of the class, you’ll be qualified to receive and use a FREE 30-day ANSYS AIM download for evaluation.

All classes will be held from 9:00 a.m. – 4:00 p.m. local time and include a complimentary lunch.

PADT’s support team of ANSYS experts will help attendees understand where ANSYS AIM fits in to their organization and workflow. The class will address both situations and how ANSYS AIM provides the integration of CAD based systems and the ease of use of a modern tool in a product that steps the occasional user through the process without limiting functionality.

Watch this short video to learn more about the capabilities and benefits of ANSYS® AIM™ for the simulation of 3-D physics and multiphysics

Contact our ANSYS experts 1-800-293-PADT,

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