All Things ANSYS 040: Live From the 2019 ASME Turbo Expo – CFD Applications for Turbomachinery

 

Published on: July 1st, 2019
With: Eric Miller, Robin Steed of ANSYS, & Chris Robinson of PCA Engineers Limited
Description:  

In this episode your host and Co-Founder of PADT, Eric Miller is joined by ANSYS CFX & Turbo Tools Lead Technical Product Manager Robin Steed, and Managing Director at PCA Engineers Limited, Chris Robinson, live at the 2019 ASME Turbo Expo in Phoenix Arizona, for a discussion on the past, present, and future of ANSYS CFD and its use in the realm of turbomachinery. Both Robin and Chris have multiple years of experience working in this industry, and their expertise provided some fascinating insight into what this tool is all about.

If you would like to learn more about what’s available in the latest CFD update check out PADT’s webinar on Fluids Updates in ANSYS 2019 R2 here: https://bit.ly/2J6l5We

If you have any questions, comments, or would like to suggest a topic for the next episode, shoot us an email at podcast@padtinc.com we would love to hear from you!

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Press Release: 2019 Commercial Vehicle Cleantech Challenge Selects PADT to Showcase Fuel Cell Blower Technology

Last week we were pleased to learn that we were selected to present our fuel cell blower technology at the Commercial Vehicle Cleantech Challenge in Denver, Colorado on July 10th. This is a great opportunity for us to share the solutions we developed for the military, automotive applications, and buses to the trucking industry. Many manufacturers of long-haul commercial trucks are looking at hybrid solutions that combine electrical drives, batteries, and hydrogen fuel cells to create zero-emission vehicles that do not require charging.

To learn more, take a look at the press release below and watch PADT’s news feed to see if we won against some pretty prestigious competition.

If you are interested in how PADT can help you solve your customer pump, blower, turbine, and fan needs, please contact us today.

Link to official press release here for html and here for PDF


2019 Commercial Vehicle Cleantech Challenge Selects PADT to Showcase Fuel Cell Blower Technology  

Major Automotive OEM’s, UTC Power and Several Government Organizations Have All Used Fuel Cell Blower Technology Developed by PADT

TEMPE, Ariz., June 27, 2019 ─ PADT, a globally recognized provider of numerical simulation, product development, and 3D printing products and services, today announced it has been selected as a finalist and to present its innovative fuel cell blower technology at the 2019 Commercial Vehicle Cleantech Challenge (CVCC) presented by the Colorado Cleantech Industries Association (CCIA) and North American Council for Freight Efficiency (NACFE). The showcase event will be held on July 10, 2019, at the Governor’s Residence in Denver, Colorado. 

“As a company who’s a proud supporter and supplier to organizations involved in the green- and cleantech space, it’s an honor to be selected to present at this event,” said Eric Miller, co-founder and principal, PADT. “We look forward to showcasing PADT’s solutions and demonstrating our history of excellence in the hydrogen fuel cell sector.”

PADT will be joined by event partners Toyota, Kenworth, Schneider, UPS, Xcel Energy, and Great Dane as well as trucking industry strategic investors, technology experts and industry environmental directors interested in technologies that can be deployed into their operations.  According to a press release from CCIA, program partners reviewed submissions, vetted applicants and ultimately selected eight finalists, including PADT, to present.

Hydrogen fuel cell technology has resurged in use in recent years and PADT remains one of the few companies with deep experience developing custom fuel cell accessory solutions for the transportation industry.

“The unique requirements of providing pressurized hydrogen and air to high-efficiency fuel-cells require custom solutions which operate at the proper pressure and flow, can deal with the safety issues presented by working with hydrogen, and operate with extremely high efficiency,” said Rob Rowan, director of engineering, PADT. “PADT is one of the few companies in the world with the experience and technical know-how to meet these needs.”

PADT has developed fuel cell blower technology solutions for a number of major automotive OEMs, UTC Power, and several government research organizations. The company’s fuel cell blower technology is still in use today by buses in Oakland, Calif., ten years after being installed.

For more information on PADT’s expertise in cleantech, please visit its alternative energy page here or contact us at 480.813.4884 or info@padtinc.com

About PADT

PADT is an engineering product and services company that focuses on helping customers who develop physical products by providing Numerical Simulation, Product Development, and 3D Printing solutions. PADT’s worldwide reputation for technical excellence and experienced staff is based on its proven record of building long-term win-win partnerships with vendors and customers. Since its establishment in 1994, companies have relied on PADT because “We Make Innovation Work.” With over 80 employees, PADT services customers from its headquarters at the Arizona State University Research Park in Tempe, Arizona, and from offices in Torrance, California, Littleton, Colorado, Albuquerque, New Mexico, Austin, Texas, and Murray, Utah, as well as through staff members located around the country. More information on PADT can be found at www.PADTINC.com.


All Things ANSYS 039: Updates for Design Engineers in ANSYS 2019 R2

 

Published on: June 17th, 2019
With: Eric Miller, Ted Harris, & Tom Chadwick
Description:  

In this episode your host and Co-Founder of PADT, Eric Miller is joined by PADT’s Simulation Support Manager Ted Harris, and Senior CFD Engineer Tom Chadwick for a discussion on what new capabilities (beta or otherwise) are available for design engineers in the latest updates made to Discovery Live in ANSYS 2019 R2.

If you would like to learn more about this update and see the tool in action, along with others in the 3D Design family of products (Discovery AIM, SpaceClaim & Live) check out PADT’s webinar on the topic here: https://bit.ly/2KfO0tK

If you have any questions, comments, or would like to suggest a topic for the next episode, shoot us an email at podcast@padtinc.com we would love to hear from you!

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3D Printing Polymer Parts with Electrostatic Dissipative (ESD) Properties

Getting zapped by static electricity at the personal level is merely annoying; having your sensitive electronic equipment buzzed is another, highly destructive story.

Much as you’d like to send these components out into the world wearing their own little anti-static wristbands, that’s just not practical (and actually, not good enough*). During build and use, advanced electronics applications need true charge-dissipative protection that is inherent to their design and easy to achieve. However, the typical steps of painting or coating, covering with conductive tape, or wrapping with carbon-filled/aluminum-coated films incur both time and cost.

Electrostatic dissipative (ESD) polymer materials instead provide this kind of protection on a built-in basis, offering a moderately conductive “exit path” that naturally dissipates the charge build-up that can occur during normal operations. It also prevents powders, dust or fine particles from sticking to the surface. Whether the task is protecting circuit boards during transport and testing, or ensuring that the final product works as designed throughout its lifetime, ESD materials present low electrical resistance while offering the required mechanical, and often thermal and/or chemically-resistant properties.

ESD-safe fixture for testing a printed-circuit board, produced by 3D printing with Stratasys ABS-ESD7 material. (Image courtesy of Stratasys)

Combining ESD Behavior with 3D Printing

All the features that are appealing with 3D printing carry over when printing with ESD-enabled thermoplastics. You can print trays custom-configured to hold circuit-boards for in-process testing, print conformal fixtures that speed up sorting, and produce end-use structures for projects where static build-up is simply not allowed (think mission-critical aerospace applications).

Acrylonitrile butadiene styrene (ABS), that work-horse of the plastics industry, has been available as 3D printing filament for decades. Along the way, Stratasys and other vendors started offering this filament in a version filled with carbon particles that decrease the plastic’s inherent electrical resistance. Stratasys ABS-ESD7 runs on the Fortus 380, 400, 450 and 900 industrial systems, and soon will be available on the office-friendly F370 printer.

What kind of performance does ABS-ESD7 offer? When evaluating materials for ESD performance, the most important property is usually the surface resistance, measured in ohms. (This is not the same as surface resistivity, plus there’s also volume resistivity – see Note at end). Conductive materials – typically metals – have a surface resistance generally less than 103 ohms, insulators such as most plastics are rated at greater than 1012 ohms, and ESD materials fall in the mid-range, at 106 to 109 ohms.

Compared to standard ABS filament, ABS-ESD7 offers more than five orders of magnitude lower resistance, converting it from an insulator to a material that provides an effective static-discharge path to the outside world. Due to the inherent layered structure of FDM parts, the differences in properties between flat (XY) and vertical (ZX) build orientations produces a range of resistance values, with a target of 107 ohms, reflected in the product name of ABS-ESD7. Stratasys offers an excellent, easy-to-read FAQ paper about ABS-ESD7.

Printed-circuit board production tool, custom 3D-printed in Stratasys ABS-ESD7 material for built-in protection from electrostatic discharge during test and handling. (Image courtesy of Stratasys)

When ABS isn’t strong enough or won’t hold up to temperature extremes, engineers can turn to Stratasys’ ESD-enhanced polyetherketoneketone (PEKK), termed Antero 840CN03. Developed in 2016 and slated for full release in October 2019, this new filament expands the company’s Antero line of  high-temperature, chemically resistant formulations. The PEKK base material offers a high glass transition temperature (Tg 149C, compared to 108C for ABS-ESD7) while meeting stringent outgassing and cleanroom requirements. As with ABS-ESD7, the carbon-nanotube loading lowers electrical resistance values of Antero 840CN03 parts to the desirable “ESD safe” range of 106 to 109 ohm.

Setting up Parts for Printing with ESD-Enhanced Filament                                                            

Support structures in contact with part walls/surfaces can disturb the surface resistance behavior. To counter-act this condition for filament printing with any type of ESD material, users should perform a special calibration that makes the printer lay down slightly thinner-than-usual layers of support material. In Stratasys Insight software, this is currently accomplished by setting the Support Offset Thickness to -0.003; this decreases the support layers from 0.010 inches to 0.007 inches. In addition, supports should be removed (in Insight software) from holes that are smaller in diameter than 0.25 inches (6.35mm).

As more of these materials are developed, the software will be updated to automatically create supports with this process in mind.

ESD Applications for 3D Printing

Avionics boxes, fixtures for holding and transporting circuit boards, storage containers for fuel, and production-line conveyor systems are just a few examples of end-use applications of ESD-enabled materials. Coupled with the geometric freedom offered by 3D printing, three categories of manufacturing and operations are improved:

  • Protecting electronics from ESD damage (static shock)
  • Preventing fire/explosion (static spark)
  • Preserving equipment/product performance (static cling)

If you’re exploring how 3D printing with ESD-enhanced materials can help with your industrial challenge, contact our PADT Manufacturing group: get your questions answered, have some sample parts printed, and discover what filament is right for you.

PADT Inc. is a globally recognized provider of Numerical Simulation, Product Development and 3D Printing products and services. For more information on Insight, GrabCAD and Stratasys products, contact us at info@padtinc.com.

*Anti-static is a qualitative term and refers to something that prevents build-up of static, rather than dissipating what does occur


Surface Resistance, Surface Resistivity and Volume Resistivity

Surface resistance in ohms is a measurement to evaluate static-dissipative packaging materials.

Surface resistivity in ohms/square is used to evaluate insulative materials where high resistance characteristics are desirable. (Ref. https://www.evaluationengineering.com/home/article/13000514/the-difference-between-surface-resistance-and-surface-resistivity)

The standard for measuring surface resistance of ESD materials is EOS/ESD S11.11, released in 1993 by the ESD Association as an improvement over ASTM D-257 (the classic standard for evaluating insulators). Driving this need was the non-homogeneous structure of ESD materials (conductive material added to plastic), which had a different effect on testing parameters such as voltage or humidity,  than found with evaluating conductors.

Volume resistivity is yet a third possible measured electrical property, though again better suited for true conductors rather than ESD material. It depends on the area of the ohmeter’s electrodes and the thickness of the material sample. Units are ohm-cm or ohm-m.

             

Fluids Updates in ANSYS 2019 R2 – Webinar

ANSYS CFD goes beyond qualitative results to deliver accurate quantitative predictions of fluid interactions and trade-offs. These insights reveal unexpected opportunities for your product — opportunities that even experienced engineering analysts can miss.

Products such as ANSYS Fluent, Polyflow, and CFX work together in a constantly improving tool kit that is developed to provide ease of use improvements for engineers simulating fluid flows and it’s impacts on physical models.

Join PADT’s Simulation Support and Application Engineer, Sina Ghods, for a look at what is new and improved for fluids-related tools in ANSYS 2019 R2. This presentation includes updates regarding:

A new fluent experience

Parallel Mosaic-enabled meshing

Discrete Phase Modeling

Creating high-quality meshes for complex models

Transient elasticity for fluid structure interaction

And much more

Register Here

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!

Ten Suggestions for Automating Product Duty Cycle Testing

No product is perfect. Much of engineering is trying to determine when a part will fail in the field or when there are field failures, why it failed and how to fix it. Although simulation and engineering experience can make a huge difference, sometimes the best way to understand product robustness in the real world is through duty cycle testing; designing a test that puts the product through the varied and repeated loading that it will see in use.

This type of testing is perfect for automation. For decades, PADT has been designing testing devices for our customers to determine durability, uncover problems, and verify that proposed solutions work. Over those years our engineers have developed guidelines that we use to design tests and test apparatus. We got together and summarized that experience in the ten suggestions listed below.

But first, it would be good to define what automated product duty cycle testing is.

Automated Product Duty Cycle Testing Defined

When a physical product is used, it sees some sort of loading; force, pressure, temperature, friction, chemicals, sunlight, etc… That loading causes deformation of the various materials used or changes the physical properties of those materials. In most cases, the deformation or property change is not permanent. But sometimes the loads are large enough or are replied long enough to cause permanent changes. Metal fatigues, rubber tubes become brittle, or glue fails.

Large loads are easy to test. You apply them and see what happens. But long term loading, especially a set of repeated loads, needs to be applied over time. This type of long-term testing that applies the loads the product will see over time is called duty cycle testing. Add in the need to apply temperatures cycles, humidity, and power loads – all things that components see in the real world – and the value of automation multiplies.

As engineers, when we see something that happens over time and repeats, we know that automation can be used to reduce cost and enforce repeatability. And that is why most duty cycle testing is automated. But those time savings and that repeatability are only effective if the test and the text fixture are designed correctly, which leads us to PADT’s ten suggestions.

1: Define the purpose and the expected outcome of the test

Most people define the purpose or the outcome, but not both. This really starts with understanding who the customer is for the test, even within the same company. What do they need from the test and why do they need it.

2: Map the full duty cycle being tested

The physical behavior of a system, especially over time, is impacted by all of the loads that the system sees. The cause of a failure or performance degradation is often not one load, but some unexpected combination of loads. You may think a problem may be caused by say, a bending load that happens tens-of-thousands of times. But it may be that bending load combined with a torque that only occurs every once in a while.

3: Document the test process, keeping it as simple as possible

Simplicity is the key here. Complexity adds cost, slows schedules, and introduces irrelevant failure modes. Designing is like writing a good story. Put everything down, then start cutting. Keep cutting until you only have exactly what you need.

4: Design the apparatus to the test

This seems obvious, but it can often be missed. The three previous suggestions need to be reviewed before, during, and after the design process. Every feature, chunk of code, or fixture needs to be there for a reason. The device must carry out the test process and apply the full duty cycle while meeting the purpose and expected outcome of the test.

5: Make the system versatile

After developing our second or third test rig, we discovered that our customers almost always wanted to add new loads or change loading. You may design a system to test one component, to find that a different component is failing more in the field so you need to change the test to load that part. If you design the apparatus to allow for easy changes that don’t require a complete redesign, you can create a far more valuable device.

6: Make the remaining human steps as easy as possible

The whole point of automation is to take humans out of the loop. But someone still has to load, unload, repair, and maintain the system. With so much focus on automation, it is easy to make the apparatus difficult to use. Human interface design still plays an important role.

7: Keep the hardware as simple as possible

Simplicity is the key to success in most designs, and automating duty cycle testing is no different. The repetitive nature of the operating steps and long run times make it especially important. Also, if you make the design too complex it is more difficult to capture and interpret results.

8: Invest in robust, off-the-shelf industrial quality equipment.

Do not try and save money using hobby or educational hardware or in making your own components, unless what you need is not commercially available. Remember, you are measuring the robustness of your product so having robust equipment to carry out the testing is critical. There is a reason why an industrial controller costs more. Invest in hardware that results in a test system that will last.

9: Spend the time and money upfront to automate as much as possible

Just as you should invest in high-quality hardware, you should put time and money into automating as much as possible. It is tempting to save money by saying “we can have a person do this step” but when you do that you introduce long term costs, delays, and a source of error.

10: Test the test before releasing the apparatus to the customer

Plan for a lot of testing of the system before official testing starts. This can seem obvious but because the focus of the design process is a test itself, it is easy to forget that the hardware and software need to be tested before they are released for use.

Better automated testing is achievable

Testing of your products should never be an afterthought or an add-on to the product’s design. Plan for it as an important part of the product lifecycle. If you follow the guidelines above and budget the proper time, money, and space (don’t forget you will need a place to do the testing) you can achieve a greater understanding of the robustness, failure modes, and efficiency of the things you make.

If you need help with duty cycle testing, please reach out to PADT. Our expertise in project management, engineering problems solving, controller programming, industry applications, and creative design are a unique combination that results in better fixture design and more useful information from your testing.

We can assist you in the design or take on the whole project, including doing the testing here at our facility. Contact us at info@padtinc.com or 480.813.4884 and ask to speak to someone in our Engineering Services Team about product testing. And don’t forget, we have world-class simulation and 3D Printing here on site to speed up the process and deliver deeper insight.

3D Design Updates in ANSYS 2019 R2 – Webinar

When it comes to the exploration of rapid 3D design, simulation provides a more efficient and optimized workflow for design engineers looking to streamline product development and improve product performance. The toolkit of flagship ANSYS 3D design products made up of Discovery SpaceClaim, Discovery Live, and Discovery AIM allow users to build, and optimize lighter and smarter products with an interface easier to use than most other simulation products. 

Users can delve deeper into the details of a design with the same accuracy as other, more robust ANSYS tools, all while refining their concept and introducing multiple physics simulations to better account for real-world conditions.

Join PADT’s Simulation Support Manager Ted Harris, for a look at what’s new for this line of products with the release of ANSYS 2019 R2. Explore updates for these three tools including:

  • Shared Topology
  • Meshing
  • Navigation
  • Modal Supports 
  • Multi-physics Coupling
  • Topology Optimization 
  • And much more

Register Here

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!

PADT’s Penchant for Patents

When they walk into PADT’s main office in Tempe, Arizona, the first thing most people notice is our “wall-o-patents.” Over the years, PADT employees have been named on 43 patents. They range from fuel cell membranes to silicon wafer coating to a slew of medical devices. When we received notification that staff members were listed as co-inventor on two patients with numbers over 10,000,000 we thought it was a good excuse to celebrate the years of contributions our engineers have made.

The rich collection highlights the diversity of industries we work on and the ingenuity of our staff. When the companies who own the Intellectual Property (IP) represented on that wall came to PADT looking for assistance with research, development, troubleshooting, and testing of their products they found a partner that did more than carry out tasks. PADT collaborated with them to create novel solutions and approaches that resulted in IP.

You can view all of our patents on our wall… or on our patent page here.

We want to say thank you to our staff and our customers for letting us be part of their innovation.

If you are looking for a partner that can work with you to turn your ideas in into Intellectual Property, please learn about our Product Development team or reach out to info@padtinc.com.

Bring Your Most Imaginative Ideas to Life with Pantone Validation on the Stratasys J750 & J735

If seeing is believing, holding something this vivid is knowing for sure.

The Stratasys J735 and J750 deliver unrivaled aesthetics to your brightest ideas and boldest ambitions with true, full-color capability, texture mapping and color gradients.

3D print prototypes that look, feel and operate like the finished products in multiple materials and colors without sacrificing time for intricacy and complexity. Better communicate designs with vivid, realistic samples, and save on manual post-processing delays and costs.

Stratasys J735 and J750 printers are PANTONE Validated™

This validation makes the Pantone Matching System (PMS) Colors available for the first time in a 3D printing solution. It provides a universal language of color that enables color-critical decisions through every stage of the workflow for brands and manufacturers. It helps define, communicate and control color from inspiration to realization.

Color matching to Pantone Colors in a single click

GrabCAD Print software provides a quicker, more realistic expression of color in your models and prototypes, saving hours over traditional paint matching or iterative color matching processes.

  • Adding Pantone color selection increases the color gamut found within the GrabCAD Print Application and simplifies the color selection process
  • Designers can access the colors directly from GrabCAD Print, selecting Pantone within the Print Settings dialog box. From within this view the user can search for their desired Pantone color or select from the list.

Multiple material selections

This means  you can load up to six materials at once, including any combination of rigid, flexible, transparent or opaque materials and their components.

Double the number of print nozzles

More print heads means you can produce ultra-smooth surfaces and fine details with layer thickness as fine as 0.014 mm—about half the width of a human skin cell.

Discover how you can achieve stronger realism and color matching thanks to the Pantone Validation available on the Stratasys J750 & J735.

Contact the industry experts at PADT via the link below for more information:

All Things ANSYS 038 – Simulating Multibody Dynamics More Accurately with ANSYS Motion

 

Published on: June 3rd, 2019
With: Eric Miller & Jim Peters
Description:  

In this episode your host and Co-Founder of PADT, Eric Miller is joined by PADT’s Senior Staff Technologist, Jim Peters for a discussion on the benefits of using ANSYS Motion to enable fast and accurate analysis of rigid and flexible bodies, and give accurate evaluation of physical events through the analysis of the mechanical system as a whole. ANSYS Motion uses four tightly integrated solving schemes: rigid body, flexible body, modal and mesh-free EasyFlex. This gives the user unparalleled capabilities to analyze systems and mechanisms in any desired combination.

If you would like to learn more about this update and see the tools in action, check out PADT’s webinar covering ANSYS Motion here: https://bit.ly/2MsRATh

If you have any questions, comments, or would like to suggest a topic for the next episode, shoot us an email at podcast@padtinc.com we would love to hear from you!

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Presentation: 3D Printing & Optics

The experts at PADT are often asked to speak at conferences around the country, even around the world. This is a great opportunity for us to present what we do and share what we know. The downside is that we only reach the people in the room. The solve this, we are going back and presenting past live seminars at our desks and recording them on BrightTalk. This is the third of those recordings. To find others go to our BrightTalk Channel

The world of optical systems is a subset of mechanical engineering with unique needs and requirements. Those unique needs also make it an ideal area to apply Additive Manufacturing, also known as 3D Printing.

This is a presentation that we gave at Photonics Days, held at the University of Arizona in Tucson Arizona from January 30th through February 1st of 2019.

You can view the presentation on BrightTALK here:
https://www.brighttalk.com/webcast/15747/360024

Meshing Updates in ANSYS 2019 R2 – Webinar

An intelligent, high-quality mesh is at the core of any effective simulation based model; creating the basis for what will help to drive valuable results for even the most complex engineering problems.

Among a variety of tools in ANSYS 2019 R2 are enhanced meshing capabilities that can help reduce pre-processing time and provide a more streamlined solution.

Join PADT’s Specialist Mechanical Engineer, Joe Woodward for a look at what new meshing capabilities are available in the latest release of ANSYS. This presentation will focus predominately on updates regarding:

ANSYS Mechanical Meshing
Batch Connections
Axisymmetric Sweep
Layered Tetrahedron Enhancements
Local Sizing Enhancements
SpaceClaim Meshing
Parameter Management
Direct Modeling/Meshing
Hex Meshing
Block Decomposition

And much more!

Register Here

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!

“Equation Based Surface” for Conformal and Non-Planar Antenna Design

ANYSY HFSS provides many options for creating non-planar and conformal shapes. In MCAD you may use shapes such as cylinders or spheres, and with some steps, you can design you antennas on various surfaces. In some applications, it is necessary to study the effect of curvatures and shapes on the antenna performance. For example for wearable antennas it is important to study the effect of bending, crumpling and air-gap between antenna and human body.

Equation Based Surface

One of the tools that HFSS offers and can be used to do parametric sweep or optimization, is “Draw equation based surface”. This can be accessed under “Draw” “Equation Based Surface” or by using “Draw” tab and choosing it from the banner (Fig. 1)

Fig. 1. (a) Select Draw -> Equation Based Surface
Fig. 1. (b) click on the icon that is highlighted

Once this is selected the Equation Based Surface window that opens gives you options to enter the equation with the two variables (_u, _v_) to define a surface. Each point of the surface can be a function of (_u,_v). The range of (_u, _v) will also be determined in this window. The types of functions that are available can be seen in “Edit Equation” window, by clicking on “…” next to X, Y or Z (Fig. 2). Alternatively, the equation can be typed inside this window. Project or Design Variables can also be used or introduced here.

Fig. 2. (a) Equation Based Surface window
Fig. 2. (b) Clikc on the “…” next to X and see the “Edit Equation: window to build the equation for X

For example an elliptical cylinder along y axis can be represented by:

This equation can be entered as shown in Fig. 3.

Fig. 3. Elliptical surface equation

Variation of this equation can be obtained by changing variables R1, R2, L and beta. Two examples are shown in Fig. 4.

Fig. 4. Elliptical surface equation

Application of Equation Based Surface in Conformal and Non-Planar Antennas

To make use of this function to transfer a planar design to a non-planar design of interest, the following steps can be taken:

  • Start with a planar design. Keep in mind that changing the surface shape can change the characteristics of the antenna. It is a good idea to use a parameterized model, to be able to change and optimize the dimensions after transferring the design on a non-planar surface. As an example we started with a planar meandered line antenna that works around 700MHz, as shown in Fig. 5. The model is excited by a wave port. Since the cylindrical surface will be built around y-axis, the model is transferred to a height to allow the substrate surface to be made (Fig 5. b)
Fig. 5. Planar meandered antenna (a) on xy plane, (b) moved to a height of 5cm
  • Next, using equation based surface, create the desired shape and with the same length as the planar substrate. Make sure that the original deisgn is at a higher location. Select the non-planar surface. Use Modeler->Surface->Thicken Sheet … and thicken the surface with the substrate thickenss. Alternatively, by choosing “Draw” tab, one can expand the Sheet dropdown menu and choose Thicken Sheet. Now select the sheet, change the material to the substrate material.
Fig. 6. Thicken the equation based surface to generate the substrate
  • At this point you are ready to transfer the antenna design to the curved surface. Select both traces of the antenna and the curved substrate (as shown in Fig. 7). Then use Modeler->Surface->Project Sheet…, this will transfer the traces to the curved surface. Please note that the original substrate is still remaining. You need not delete it.
Fig. 7. Steps for transferring the design to the curved surface (a)

Fig. 7. Steps for transferring the design to the curved surface (b)

Fig. 7. Steps for transferring the design to the curved surface (c)
  • Next step is to generate the ground plane and move the wave port. In our example design we have a partial ground plane. For ground plane surface we use the same method to generate an equation based surface. Please keep in mind that the Z coordinate of this surface should be the same as substrate minus the thickness of the substrate. (If you thickened the substrate surface to both sides, this should be the height of substrate minus half of the substrate thickness). Once this sheet is generate assign a Perfect E or Finite Conductivity Boundary (by selecting the surface, right click and Assign Boundary). Delete the old planar ground plane.
Fig. 8. Non-planar meandered antenna with non-planar ground

Wave Port Placement using Equation Based Curve

A new wave port can be defined by the following steps:

  • Delete the old port.
  • Use Draw->Equation Based Curve. Mimicking the equation used for ground plane (Fig. 9).
Fig. 9. Use Equation Based Curve to start a new wave port (a) Equation Based Curve definition window (b) wave pot terminal created using equation based curve and sweep along vector
  • Select the line from the Model tree, select Draw->Sweep->Along Vector. Draw a vector in the direction of port height. Then by selecting the SweepAlongVector from Model tree and double clicking, the window allows you to set the correct size of port height and vector start point (Fig. 10).
  • Assign wave port to this new surface.
Fig. 10. Sweep along vector to create the new wave port location

Similar method can be used to generate (sin)^n or (cos)^n surfaces. Some examples are shown in Fig. 11. Fig. 11 (a) shows how the surface was defined.

Fig. 11. (a) Equation based surface definition using “cos” function, (b), (c), & (d) three different surfaces generated by this equation based surface.

Effect of Curvature on Antenna Matching

Bending a substrate can change the transmission line and antenna impedance. By using equation based port the change in transmission line impedance effect is removed. However, the overall radiation surface is also changed that will have effects on S11. The results of S11 for the planar design, cylindrical design (Fig. 8), cos (Fig. 11 b), and cos^3 (Fig. 11 c) designs are shown in Fig. 12. If it is of interest to include the change in the transmission line impedance, the port should be kept in a rectangular shape.

Fig. 12. Effect of curvature on the resonance frequency.

Equation based curves and surfaces can take a bit of time to get used to but with a little practice these methods can really open the door to some sophisticated geometry. It is also interesting to see how much the geometry can impact a simple antenna design, especially with today’s growing popularity in flex circuitry. Be sure to check out this related webinar  that touches on the impact of packaging antennas as well. If you would like more information on how these tools may be able to help you and your design, please let us know at info@padtinc.com.

You can also click here to download a copy of this example.

Four Different Ways to Add Customization to ANSYS Mechanical

ANSYS Mechanical is a very powerful tool right out of the box.  Long gone are the days when an FEA tool was just a solver, and users had to write code to create input files and interpret the results.  Most of the time you never have to write anything to effectively use ANSYS Mechanical. But, users can realize significant gains in productivity and access greater functionality through customization. And it is easy to do.

Before we talk about the four options, we need to remember how the tool, ANSYS Mechanical, is actually structured.  The interface that users interact with is a version of ANSYS Workbench called ANSYS Mechanical. The interface allows users to connect to geometry, build and modify their model, set up their solution, submit a solve, and review results. The solve itself is done in ANSYS Mechanical APDL. This is the original ANSYS Multiphysics program. 

When you press the solve button ANSYS Mechanical writes out commands in the languages used by ANSYS Mechanical APDL, called the ANSYS Parametric Design Language, or APDL.  Yes, that is where ANSYS Mechanical APDL got its name. We like to call it MAPDL for short. (Side note: years ago we started a campaign to call it map-dul. It didn’t work.) Once the file is written, MAPDL is started, the file is read in, the solve happens, and all of the requested output files are written. Then ANSYS Mechanical reads those files and shows results to the user.

Customization Tool 1: Command Snippets for Controlling the Solver

Not every capability that is found in ANSYS Mechanical APDL is exposed in the interface for ANSYS Mechanical.  That is not a problem because users can use the APDL language in ANSYS Mechanical to access the full capability of the solver.  These small pieces of code are called Snippets and they are added to the tree for your ANSYS Mechanical model.  When the solver file is written, ANSYS Mechanical inserts your snippets into the command stream.  Simple and elegant.

PADT has a seminar from back in 2011 that lays it all out.  You can find the PowerPoint Presentation here. We do have plans to update this webinar soon.

This approach is used when you want to access capabilities in the solver that are not supported in the interface but you want to get to those features and keep track of them from inside your ANSYS Mechanical Model.

If you are not familiar with APDL, find a more “seasoned” user to help you. Or you can teach yourself APDL programming with PADT’s Guide to APDL .

Customization Tool 2: ANSYS Customization Toolkit (ACT) for Controlling the User Interface and Accessing the Model

As mentioned above, ANSYS Mechanical is used to define the model and review results.  The ANSYS Customization Toolkit (ACT) is how users customize the user interface, automate tasks in the interface, add tools to the interface, and access the model database. This type of customization can be as simple as a new feature, presented as an app, or it can be used to create a focused tool to streamline a certain type of simulation – what we call a vertical application.

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A Vertical Application Written in ANSYS ACT by PADT for Automating the Design of Turbine Disks

Unlike APDL, ACT does is not have its own language. It uses Python and is a collection of Application Programmer Interface (API) calls from Python. This is a very powerful toolset that increases in capability at every release.  PADT has written stand alone applications using ACT to reduce simulation time significantly. We have also written features and apps for ourselves and users that make everyday use of ANSYS Mechanical better. 

Do note that ACT is supported in most of the major ANSYS products and more capability is being added across the available programs over time, not just in ANSYS Mechanical. You can also use ACT to connect ANSYS Mechanical to in-house or 3rd party software.

Because this is a standard environment, you can share your ACT applications on the ANSYS App Store found here. Take a look and you can see what users have done with ACT across the ANSYS Product suite, including ANSYS Mechanical.   PADT has two in the library, one for adding a PID controller to your model and the other is a tool for saving your ANSYS Mechanical APDL database.

Another great aspect of ACT is that it is fully documented.  If you go to the Customization Suite documentation in the ANSYS help library you can find everything you need.

Customization Tool 3: APDL for Automating the Solve  

With Code Snippets we talked about using APDL to access solver functions from ANSYS Mechanical that were not supported in ANSYS Mechanical.  You can also use APDL to automate what is going on during the solve.  Every capability in the ANSYS solver is accessible through APDL.

The most common usage of APDL is to create a tool that solves in batch mode. APDL programs are used to carry out tasks without going back to ANSYS Mechanical.  As an example, maybe you want to solve a load step, save some information from the solve, export it, read it in to a 3rd party program, modify it, modify some property in your model, then solve the next load step. You can do all of that with APDL in batch mode.

This is not for the faint of heart, you are getting into complex programming with a custom language. But if you take the time, it can be very powerful.  All of the commands are documented in the ANSYS Mechanical APDL help and details on the language are in the ANSYS Parametric Design Language Guide.  The PADT Blog is full of articles going back over a decade on using APDL in this way.

Customization Tool 4: User Programable Features in the Solver

One of the most powerful capabilities in the ANSYS Mechanical ADPL solver is the ability for end-users to add their own subroutines.  These User Programable Features, or UPF’s, allow you to create your own elements, make custom material models, customize loads, or customize contact behavior.

There are other general purpose FEA tools on the market that heavily publicize their user elements and user materials and they try to use it to differentiate themselves from ANSYS. However, ANSYS Mechanical APDL has always had this capability.  Many universities and companies add new capability to ANSYS using this method.

To learn more about how to do create your own custom version of ANSYS, consult the Programer’s Reference in the ANSYS Help. PADT also has a webinar sharing how to make a custom material here.

Next Steps

The key to successful customization ANSYS is to know your options, understand what you really want to do, and to use the wide range of tools you have available. Everything is documented in the help and this blog has some great examples.  Start small with a simple project and work your way up.

Or, you can leverage PADT’s expertise and contract with PADT to do your customization. This is what a half-dozen companies large and small have done over the years.  We understand ANSYS, we get engineering, and we know how to program. A perfect combination.

Regardless of how you customize ANSYS Mechanical, you will find it a rewording experience.  Greater functionality and more efficient usage are only a few lines of custom code away.

Presentation: If you are not scared, you are doing it wrong! Successful founders take risks

Legacy Presentation Series

The experts at PADT are often asked to speak at conferences around the country, even around the world. This is a great opportunity for us to present what we do and share what we know. The downside is that we only reach the people in the room. The solve this, we are going back and presenting past live seminars at our desks and recording them on BrightTalk. This is the second of those recordings. To find others go to our BrightTalk Channel

Fear can be an incredible motivator, especially in a small and growing business. This talk, originally presented at Phoenix Startup Week in 2018, goes over how being scared can be a good thing.

View the presentation here:
https://www.brighttalk.com/webcast/15747/359366