InSilixa Uses Advanced FEA to Study Real-World Gasket Behavior

In 2018, we invited some SOLIDWORKS Simulation Premium users to try our newest simulation offering: Structural Professional Engineer, a powerful and realistic cloud-based structural simulation solution. The goal of this lighthouse program was to get real feedback from real SOLIDWORKS Simulation users, working on real industrial projects and in real working conditions.

Michael T. Taylor, Staff Mechanical Engineer at InSilixa, joined the Lighthouse Program and kindly agreed to share some of his results with the SOLIDWORKS community regarding the benefit of Structural Professional Engineer for large deflection analysis of soft rubber materials.

InSilixa, Inc., is a multidisciplinary team comprised of industry veterans with diverse backgrounds in semiconductors, biotechnology, medicine, and informatics. Founded in 2012, InSilixa is driven by the quest to democratize and drive down the cost of molecular diagnostics worldwide by leveraging its proprietary complementary metal-oxide-semiconductor (CMOS) biochip technology.

A quarter section of a microfluidic device was created, in order to study the behavior of a soft rubber gasket under compression. The model is fixed at the base and a downward displacement is imposed on the top surface, to squeeze the gasket. At first glance this seems a simple problem to solve, but in fact it is actually a deceptively difficult problem to solve as it includes hyper elastic material models, large strains and contact with friction. This requires the use of a nonlinear analysis approach. InSilixa decided that this was an ideal opportunity to test the new nonlinear solution for SOLIDWORKS users, Structural Professional Engineer.

Structural Professional Engineer enables SOLIDWORKS users to access the power and technology of SIMULIA to worlds leading provider of structural Finite Element Analysis (FEA) software. Structural Professional Engineer uses a bespoke ‘Connector’ for SOLIDWORKS Simulation Premium user to transfer both the geometry and analysis set up to Structural Professional Engineer where it can be modified if necessary and solved using the powerful high-end Abaqus solver.

The pre-compressed finite element model, shown below, was generated using SOLIDWORKS Simulation Premium for a non linear solution. The loads and boundary conditions were easily applied as a hyper elastic material defined for the gasket. A quarter model is used as the problem is symmetric in nature and this will both speed up the solution and stabilize the model with symmetry constraints. Note the creation of tetrahedral (TET) elements by the mesh generator.

SOLIDWORKS Simulation Premium is a good solver of basic nonlinear problems where the number and extent of the nonlinearity is limited, fictionless metal conatct or permanent metal deformation. However this problem has multiple and extreme non linearites in material and contact friction and the SOLIDWORKS Simulation Premium solver ran into convergence problems. It is common for a non-linear analysis to require some tuning to converge to a complete solution but rather than continuing to refine the SOLIDWORKS Simulation analysis in the hope of achieving a solution InSilixa decided to run the same problem in Structural Professional Engineer for an ’Apples to Apples’ comparison.

The FEA model initially created in SOLIDWORKS Simulation Premium was imported to Structural Professional Engineer through the Connector, and set up modified in Structural Professional Engineer with a more refined material model and contact behavor. Note the model shown below includes the use of hexahedral, or brick type elements for the gasket, instead of TET elements to help with the problem to convergence to a complete solution.

InSilixa were impressed and pleased that Structural Professional Engineer produced the full result shown below in about 40 minutes, without further adjustments of the solver default settings. The gasket was squeezed well beyond the design intent, in order to fully understand the shape the gasket might take, and the force required to achieve compression.

InSilixa found Structural Professional Engineer to be a useful and powerful tool, providing beneficial insight from the simulation to help guide the design of gaskets and hardware for physical prototyping and testing. As an added bonus, the Structural Professional Engineer solver runs independent of SOLIDWORKS. Once the import into Structural Professional Engineer has completed, Structural Professional Engineer can run the FEA model while SOLIDWORKS can be used for other design tasks, since the SOLIDWORKS seat is not tied up during the run. It is even possible to shut SOLIDWORKS down during the Structural Professional Engineer run, or start it up later to perform other tasks, allowing one to multitask and increase productivity.

Michael T Taylor, Staff Mechanical Engineer, InSilixa

For more information about SIMULIA Structural Professional Engineer or our other simulation solutions, please visit our website https://www.solidworks.com/category/simulation-solutions or contact your local SOLIDWORKS reseller.

Find more information about InSilixa: www.InSilixa.com