Understanding Complex Material Behavior – Plasticity Models

There are geometric, material, and contact nonlinearities that can result from modeling with complex materials. As I mentioned in my previous blog, the Structural Performance Engineer role in SIMULIAworks was developed with SOLIDWORKS users in mind.

Design engineers often avoid nonlinear static analysis because of its complexity, but now it is in a more designer-friendly environment. And the connector within SOLIDWORKS Simulation makes it easy to transfer models to SIMULIAworks.

Plasticity modeling is typically something you do after running an initial linear elastic study to make sure that you prescribe the correct boundary conditions and loads. Plasticity modeling will increase solution accuracy and provide a better representation of the final stresses.

Discovering Deformations

Plasticity models in Structural Performance Engineer mimic real-world materials from plastics to metals, from ABS to aluminum. Many materials behave elastically up until a certain point. After that, plasticity will occur and eventually, the part (or product) will break or become permanently deformed.

That’s why it’s vital to include the plasticity in the analysis of a model; it will give you much more realistic and accurate simulation results.

Do you remember the so-called “bendgate” of an Apple iPhone? With a nonlinear analysis of the plasticity model, a designer could have identified and subsequently prevented the design issue early in the development cycle. Unfortunately, the product was delivered to the market resulting in problems, complaints, bad press, and even lawsuits filed against Apple.

The beauty of plasticity models is that the designer will now be able to see any permanent deformations. Take a look at the simple uniaxial test on the metal specimen chart below.

Consider the machine (below) that bends profiles of aluminum. The designer will be able to apply in the simulation the first step of 180 degrees and then the release. In the results, the designer will see, after the elastic return, how much the profile has bent to understand if the machine does the job—even before even builds it!

For this model, multiple contacts are provided by the ABAQUS General Contact. I used a mixed mesh approach with Hex and Tet mesh elements. It is a multi-step approach where I can easily set up a step in a direction and then a second step in the opposite direction. And that’s it—very simple to define. The complete analysis from setup to results took less than an hour.

Leverage Cloud Servers

For more detailed information, check out my webinar on analyzing complex materials, which includes a section on plasticity modeling.

Remember that SIMULIAworks is on the 3DEXPERIENCE® platform, which helps augment computing power by running your nonlinear studies in the cloud, freeing up local resources. Plus, you can work from the office or at home or on the road. All you need is an internet connection and a browser.

Nonlinear analysis is more complex than linear analysis but probably not as complicated as you may have been led to believe. I look forward to your comments below or contact your local reseller if you wish to learn more about the SIMULIAworks Structural Performance Engineer role for nonlinear analysis of SOLIDWORKS models.

Alessandro Bellini

Technical Manager with more than 15 years of experience in Pre-Sales and Post-Sales activities in CAD-related market. Strong knowledge about Simulation products, PDM and implementation projects. Deep experience in manufacturing companies processes and workflows. 6 Years of experience in managing Resellers in a global environment in Italy, Balkans, Turkey, Israel, Middle East and North Africa.