The business world has changed. Things are more competitive and everyone you are trying to partner with is much busier and has more responsibility. In a world where most people are simply struggling to react, there is a way to set yourself or your company apart. “A competitive advantage, being proactive” looks at what we try to do here at PADT to make that difference.
Getting a new product manufactured is one of those critical steps that new companies often assume is just a matter of finding a vendor and outsourcing it. In “Getting your product made: 6 suggestions for outsourcing the manufacturing of your product” I go over some suggestions on how to make this critical step a success.
September is here and it is a jam packed month of events, many of them related to BioMedical engineering. We are continuing with ANSYS webinars and talking about 3D Printing as well. See what we have below:
The UMA Summit is a day long event filled with networking, guest speakers and informative information. In between speakers network with our vendor booths and see the latest products and services available for the Manufacturing Industry. PADT will be there with lots of example of 3D Printing and ready to engage on how manufacturing really does drive innovation. Check out the event page for times and an agenda.
September 15: Scottsdale, AZ
ANSYS Arizona Innovation Conference
ANSYS and PADT are pleased to announce that we be holding a user meeting in Scottsdale for the entire ANSYS use community. Join us for an informative conference on how to incorporate various productivity enhancement tools and techniques into your workflow for your engineering department. ANSYS Applications Engineers and local customers like Honeywell, Galtronics, On Semi, Ping, and Nammo Talley, will discuss design challenges and how simulation-driven product development can help engineers rapidly innovate new products. See the agenda and register here.
September 19: Phoenix, AZ
Seminar: Medical Device Product Development for Startups – The Bitter Pill
We will be kicking off our Arizona Bioscience Week with this a free seminar at CEI in Phoenix with a sometimes brutally honest discussion on the reality of medical device product development.
No one wants to discourage a good idea, and entrepreneurs make it a long way before someone sits them down and explains how long and expensive the engineering of a medical device product is. In this one hour seminar PADT will share the hard and cold realities of the process, not to discourage people, but to give them the facts they need.
Get the details and register here.
September 21-22: Minneapolis, MN
Medical Design & Manufacturing Minneapolis
PADT Medical will have a booth with our partner Innosurg at this premier event for medical device development. For 22 years, Medical Design & Manufacturing Minneapolis has been the medtech innovation, communication, and solution epicenter of the Midwest. Now over 600 suppliers strong, and with more than 5,000 industry professionals in attendance, the event provides the solutions, education, and partnerships you simply won’t find anywhere else. Learn more here. And if you are attending, please stop by and say hello, we are in booth 1643.
Join PADT and others for this annual event that recognizes those that contribute to the growing AZ BioTech community. The awards will be made by PADT’s 3D Printing team again this year. Stop by our table to say hello. Register here.
September 21 & 22: Phoenix, AZ
White Hat Investor Conference
The West was won by innovators, investors, and prospectors who understood the value of discovery and accepted the challenge of investing in new frontiers. PADT will be joining others in the investment community to meet with and hear from companies (32 are signed up to present right now) in the Bioscience space and to also share ideas and network. Registration for this special event can be found here.
Geek out on all things technology. The New Mexico Tech community will gather the best and the brightest entrepreneurs, technicians, hackers, and tech fans for presentations, talks, meet-ups, and parties; all to highlight the vibrant tech community in our city. The Conference takes place on the final day of a week of events, and will focus on HR, CRM, Manufacturing, and Creative concerns of the tech community with panels and presentations. PADT’s Eric Miller will be presenting in two “MakeIT” sessions.
Learn more here.
This month’s webinars look at Signal Integrity and 3D Printing for Production
|Wednesday, September 7, 2016 – 1:00 PM AZ/PDT, 12:00 PM MDT
Investigating Signal Integrity: How to find problems before they find you
|Thursday, September 29, 2016 – 4:00 PM AZ/PDT, 3:00 PM MDT
SAE Webinar: Additive Manufacturing: From Prototyping to Production Parts
We are pleased to announce the new Flownex Training Course for Flownex SE, the world’s best (we think) thermal-fluid modeling tool. The Flownex course is aimed at new users with a desire to quickly equip themselves in the basics of system modelling as well as enabling one to visually refresh one’s memory on the various capabilities and applications within the Flownex suite.
If you are not a user already but want to check this tool out by going through the training course, go to the login page and simply click “Don’t have an account?” and register. This will get you access and we will follow up with a temp key so you can try it out. This is actually the best way for you to get a feel for why we like this program so much.
Here is a list of the sessions:
- Session 1: Background to Flownex
- Session 2: Page navigation
- Session 3: Boundary values
- Session 4: Pumps & Fixed mass flow functionality
- Session 5: Flow restrictions
- Session 6: Exercise 1
- Session 7: Designer functionality
- Session 8: Heat Exchangers
- Session 9: Containers
- Session 10: Exercise 2
- Session 11: Excel component
- Session 12: Visualization
As always, If you have any questions or want to know more, reach out to us at email@example.com or 1.800.293.PADT.
This is a common question that we get, particularly those coming from APDL – how to get nodal and element IDs exposed in ANSYS Mechanical. Whether that’s for troubleshooting or information gathering, it was not available before. This video shows how an ANSYS developed extension accomplishes that pretty easily.
The extension can be found by downloading “FE Info XX” for the version XX of ANSYS you are using at https://support.ansys.com/AnsysCustom…
People around the country are starting to recognize that Arizona is a great place to grow tech startups. Right now our big advantages is low cost but we can do more. In “Being the lower cost option is just the start – 5 ways we can make Arizona a preferred place for growing startups” I suggest five things we can focus on as a community to make that happen.
Updated (8/30/2016): Two corrections made following suggestions by Gilbert Peters: the first corrects the use of honeycomb structures in radiator grille applications as being for flow conditioning, the second corrects the use of the Maxwell stability criterion, replacing the space frame example with an octet truss.
This is my first detailed post in a series on cellular structures for additive manufacturing, following an introductory post I wrote where I classified the research landscape in this area into four elements: design, analysis, manufacturing and implementation.
Within the design element, the first step in implementing cellular structures in Additive Manufacturing (AM) is selecting the appropriate unit cell(s). The unit cell is selected based on the performance desired of it as well as the manufacturability of the cells. In this post, I wish to delve deeper into the different types of cellular structures and why the classification is important. This will set the stage for defining criteria for why certain unit cell designs are preferable over others, which I will attempt in future posts. This post will also explain in greater detail what a “lattice” structure, a term that is often erroneously used to describe all cellular solids, truly is.
Honeycombs are prismatic, 2-dimensional cellular designs extruded in the 3rd dimension, like the well-known hexagonal honeycomb shown in Figure 1. All cross-sections through the 3rd dimension are thus identical, making honeycombs somewhat easy to model. Though the hexagonal honeycomb is most well known, the term applies to all designs that have this prismatic property, including square and triangular honeycombs. Honeycombs have a strong anisotropy in the 3rd dimension – in fact, the modulus of regular hexagonal and triangular honeycombs is transversely isotropic – equal in all directions in the plane but very different out-of-plane.
1.2 Design Implications
The 2D nature of honeycomb structures means that their use is beneficial when the environmental conditions are predictable and the honeycomb design can be oriented in such a way to extract maximum benefit. One such example is the crash structure in Figure 2 as well as a range of sandwich panels. Several automotive radiator grilles are also of a honeycomb design to condition the flow of air. In both cases, the direction of the environmental stimulus is known – in the former, the impact load, in the latter, airflow.
2. Open-Cell Foam
Freeing up the prismatic requirement on the honeycomb brings us to a fully 3-dimensional open-cell foam design as shown in one representation of a unit cell in Figure 3. Typically, open-cell foams are bending-dominated, distinguishing them from stretch-dominated lattices, which are discussed in more detail in a following section on lattices.
2.2 Design Implications
Unlike the honeycomb, open cell foam designs are more useful when the environmental stimulus (stress, flow, heat) is not as predictable and unidirectional. The bending dominated mechanism of deformation make open-cell foams ideal for energy absorption – stretch dominated structures tend to be stiffer. As a result of this, applications that require energy absorption such as mattresses and crumple zones in complex structures. The interconnectivity of open-cell foams also makes them a candidate for applications requiring fluid flow through the structure.
3. Closed-Cell Foam
As the name suggests, closed cell foams are open-cell foams with enclosed cells, such as the representation shown in Figure 6. This typically involves a membrane like structure that may be of varying thickness from the strut-like structures, though this is not necessary. Closed-cell foams arise from a lot of natural processes and are commonly found in nature. In man-made entities, they are commonly found in the food industry (bread, chocolate) and in engineering applications where the enclosed cell is filled with some fluid (like air in bubble wrap, foam for bicycle helmets and fragile packaging).
3.2 Design Implications
The primary benefit of closed cell foams is the ability to encapsulate a fluid of different properties for compressive resilience. From a structural standpoint, while the membrane is a load-bearing part of the structure under certain loads, the additional material and manufacturing burden can be hard to justify. Within the AM context, this is a key area of interest for those exploring 3D printing food products in particular but may also have value for biomimetic applications.
Lattices are in appearance very similar to open cell foams but differ in that lattice member deformation is stretch-dominated, as opposed to bending*. This is important since for the same material allocation, structures tend to be stiffer in tension and/or compression compared to bending – by contrast, bending dominated structures typically absorb more energy and are more compliant.
So the question is – when does an open cell foam become stretch dominated and therefore, a lattice? Fortunately, there is an
app equation for that.
Maxwell’s Stability Criterion
Maxwell’s stability criterion involves the computation of a metric M for a lattice-like structure with b struts and j joints as follows:
In 2D structures: M = b – 2j + 3
In 3D structures: M = b – 3j + 6
Per Maxwell’s criterion, for our purposes here where the joints are locked (and not pinned), if M < 0, we get a structure that is bending dominated. If M >= 0, the structure is stretch dominated. The former constitutes an open-cell foam, the latter a lattice.
There are several approaches to establishing the appropriateness of a lattice design for a structural applications (connectivity, static and kinematic determinism etc.) and how they are applied to periodic structures and space frames. It is easy for one (including for this author) to confuse these ideas and their applicability. For the purposes of AM, Maxwell’s Stability Criterion for 3D structures is a sufficient condition for static determinancy. Further, for a periodic structure to be truly space-filling (as we need for AM applications), there is no simple rigid polyhedron that fits the bill – we need a combination of polyhedra (such as an octahedron and tetrahedron in the octet truss shown in the video below) to generate true space filling, and rigid structures. The 2001 papers by Deshpande, Ashby and Fleck illustrate these ideas in greater detail and are referenced at the end of this post.
Video: The octet truss is a classic stretch-dominated structure, with b = 36 struts, j = 14 joints and M = 0 [Attr. Lawrence Livermore National Labs]
4.2 Design Implications
Lattices are the most common cellular solid studied in AM – this is primarily on account of their strong structural performance in applications where high stiffness-to-weight ratio is desired (such as aerospace), or where stiffness modulation is important (such as in medical implants). However, it is important to realize that there are other cellular representations that have a range of other benefits that lattice designs cannot provide.
Conclusion: Why this matters
It is a fair question to ask why this matters – is this all just semantics? I would like to argue that the above classification is vital since it represents the first stage of selecting a unit cell for a particular function. Generally speaking, the following guidelines apply:
- Honeycomb structures for predictable, unidirectional loading or flow
- Open cell foams where energy absorption and compliance is important
- Closed cell foams for fluid-filled and hydrostatic applications
- Lattice structures where stiffness and resistance to bending is critical
Finally, another reason it is important to retain the bigger picture on all cellular solids is it ensures that the discussion of what we can do with AM and cellular solids includes all the possibilities and is not limited to only stiffness driven lattice designs.
Note: This blog post is part of a series on “Additive Manufacturing of Cellular Solids” that I am writing over the coming year, diving deep into the fundamentals of this exciting and fast evolving topic. To ensure you get each post (~2 a month) or to give me feedback for improvement, please connect with me on LinkedIn.
 Ashby, “Materials Selection in Mechanical Design,” Fourth Edition, 2011
 Gibson & Ashby, “Cellular Solids: Structure & Properties,” Second Edition, 1997
 Gibson, Ashby & Harley, “Cellular Materials in Nature & Medicine,” First Edition, 2010
 Ashby, Evans, Fleck, Gibson, Hutchinson, Wadley, “Metal Foams: A Design Guide,” First Edition, 2000
 Deshpande, Ashby, Fleck, “Foam Topology Bending versus Stretching Dominated Architectures,” Acta Materialia 49, 2001
 Deshpande, Fleck, Ashby, “Effective properties of the octet-truss lattice material,” Journal of the Mechanics and Physics of Solids, 49, 2001
* We defer to reference  in distinguishing lattice structures as separate from foams – this is NOT the approach used in  and  where lattices are treated implicitly as a subset of open-cell foams. The distinction is useful from a structural perspective and as such is retained here.
After three years on the market and signs that sales were increasing year over year, we decided it was time to go through our popular training book “Introduction to the ANSYS Parametric
Design Language (APDL)” and make some updates and reformat it so that it can be published as a Kindle e-book. The new Second Edition includes two additonal chapters: APDL Math and Using APDL with ANSYS Mechanical. The fact that we continue to sell more of these useful books is a sign that APDL is still a vibrant and well used language, and that others out there find power in its simplicity and depth.
This book started life as a class that PADT taught for many years. Then over time people asked if they could buy the notes. And then they asked for a real book. The bulk of the content came from Jeff Strain with input from most of our technical staff. Much of the editing and new content was done by Susanna Young and Eric Miller.
Here is the Description from Amazon.com:
The definitive guide to the ANSYS Parametric Design Language (APDL), the command language for the ANSYS Mechanical APDL product from ANSYS, Inc. PADT has converted their popular “Introduction to APDL” class into a guide so that users can teach themselves the APDL language at their own pace. Its 14 chapters include reference information, examples, tips and hints, and eight workshops. Topics covered include:
– User Interfacing
– Program Flow
– Retrieving Database Information
– Arrays, Tables, and Strings
– Importing Data
– Writing Output to Files
– Menu Customization
– APDL Math
– Using APDL in ANSYS Mechanical
At only $75.00 it is an investment that will pay for itself quickly. Even if you are an ANSYS Mechanical user, you can still benefit from knowing APDL, allowing you to add code snippets to your models. We have put some images below and you can also learn more here or go straight to Amazon.com to purchase the paperback or Kindle versions.
This week’s TechFlash focuses on the role that small technical companies play in providing key Research & Development contributions to significant projects. Inspired by a visit to just such a company in Utah, “Small tech businesses R&D to the rescue” shares our experience in this area.
In the Age of IoT, electronics continue to get smaller, faster, more power efficient, and are integrated into everything around us. Increasingly, companies are incorporating simulation early in the product development process, when the cost of design changes are at their lowest, to meet the challenges presented by Signal Integrity. For this to be effective, simulation tools need to be easy-to-use, compatible with existing work flows, and accurate, all while delivering meaningful results quickly.
If you or your company are designing or using electronics that are:
Critical to revenue, performance, or safety
Getting smaller, faster, or more efficient
Communicating with Gbps data rates
Using several or new connectors
Using long cables or backplanes
Then you could be a victim of Signal Integrity failure!
Join us September 7th, 2016 at 1 pm Pacific Time for this free webinar to discover how ANSYS is delivering intuitive Signal Integrity analysis solutions that can easily import ECAD geometry to compute SYZ parameters, inter-trace coupling, or impedance variations. Learn how ANSYS can help identify Signal Integrity problems and optimize potential solutions faster and cheaper than prototyping multiple iterations.
This webinar will introduce:
- What products ANSYS provides for Signal Integrity problems
- How these products can integrate into existing design workflows
- And how easy these products are to use, even for novice operators
Followed by a Q&A session!
Click Here to register for this event and be sure to add it to your calendar to receive reminders.
Can’t make it? We suggest you register regardless, as our webinars are recorded and sent out along with a PDF of the presentation to our contacts within 24 hours of the presentation finishing.
PADT’s Eric Miller was asked to return to take part in a discussion about the somewhat hidden Space industry in Arizona. Eric was joined by Kjell Stakkestad, CEO of KinetX Aerospace to answer questions and provide insight into this critical part of Arizona’s high tech industry landscape.
The show features some serious but not-so-fun topics… and the title for the video reflects those. So ignore the title and see what Eric and Kjell have to say starting at 17:55.
I feel a little awkward as an engineer giving advice on marketing, but this stuff works for us and there is no reason it can’t work for others. In “5 simple goals for social network marketing” I go over the goals we have found that helped us build a Social Networking strategy that has proven to help our business. Heck, you are reading this post so we must be doing something right.
Business is often a process of trying to influence people to do something you want. Study after study shows something simple, the approach that seemed to work over and over again was the simplest: make things easy. In “Nudging behavior by making things easy” I look at this phenomenon and relate it to the business of high technology.
ANSYS Mechanical allows you to specify settings for load steps one at a time. Most users don’t know that you can change settings for any combination of load steps using the selection of the load step graph. PADT’s Joe Woodward shows you how in this short but informative video.