Compute Mechanics & Deformation
Composite materials play a crucial role for light weight applications, but the analysis of their behavior is challenging due to the highly anisotropic behavior and the complex damage mechanisms they exhibit. The expensive, time consuming and often impracticable experimental tests for the study of composites can be supplemented or replaced by simulation.
The ElastoDict module helps characterizing the mechanical properties of composites, to understand and optimize the material using accurate simulations on the 3D microstructure. For example, it is possible to carry out simulations of anisotropic stiffness, damage and material failure, which can also be seen directly on CT images when examining existing materials.
The properties of new material designs can be computed on 3D structural models, which can be created e.g. with FiberGeo. The exact results at the microstructure scale can be used to improve component simulations.
Using simulation to find answers to mechanical properties and deformation questions is key not only for composites, but also for porous materials. For example, the ElastoDict module can be used to simulate how the clamping pressure changes the structure of a gas diffusion layer (GDL) in a PEM fuel cell, or how the properties of rock samples change under in-situ conditions.
All these ElastoDict simulations run at high-speed and in a extremely memory-efficient way with the FeelMath solver integrated in ElastoDict and developed at the Fraunhofer ITWM.
AF computes analytic approximations and bounds for the linear elastic properties of complex micro-structures. The computation is very fast, as no partial differential equation is solved, and gives a first approximation of the material behavior.
VOX accurately computes the linear elastic properties of complex micro-structures by solving the corresponding partial differential equation on the 3D image or model. The results include the local von Mises stress (revealing possible points of material failure), the complete stiffness tensor, and the information on the orthotropic, transversal isotropic or isotropic character of the material, indicative of directionally dependent properties. Additionally, many post-processing steps can be carried out on the VOX results.
LD simulates nonlinear large deformations. For example, a standard tensile experiment in an arbitrary direction of the 3D micro-structure can be set up. The models of the constituent materials might contain damage, failure, plastic deformation, viscous effects, and many more. To model the constituent materials, Abaqus UMAT’s can be used to include all kinds of possible effects in the nonlinear simulation.
Results of the simulation are e.g. a strain-stress curve and local information on the regions where damage sets in and the material ends up failing. Cyclic load experiments or shear experiments are also possible. The LD simulation also delivers deformed 3D structures from each computed deformation step for visualization and further analysis.