This presentation was made at CAASE18, The Conference on Advancing Analysis & Simulation in Engineering. CAASE18 brought together the leading visionaries, developers, and practitioners of CAE-related technologies in an open forum, to share experiences, discuss relevant trends, discover common themes, and explore future issues.

Resource Abstract

In the past years, topology optimization and shape optimization have been increasingly established as standard method to support the load path dependent layout of mechanical parts under weight, stress, and durability constraints. Beside the creation of design ideas, users of topology optimization often want to achieve the final design by this type of optimization based on their material and loading definitions without further design work. These requirements lead to a simulation-driven design process, where topology optimization and shape optimization are combined to obtain the desired design. The key point of the design process is a software concept, where all necessary analysis steps and the optimization are integrated in one single software.

While topology optimization is often used with static load cases, special focus is put here on dynamic loading. However, studies have shown that the optimal layout under dynamic loads is considerably different from layouts under static loads. In addition, it is very important to model the boundary conditions of the part to be optimized as realistic as possible. The best way is to bring all connected parts into the model and use reduction methods where possible.

Moreover, because topology optimization has limited capabilities to determine the stress distribution in the optimized part, a subsequent shape optimization has to be considered to complete the design process. Because the shape found by topology optimization has a free geometry, a free-form optimization method is the right choice for this task. Both stress and weight optimization are supported by freeform optimization under additional constraints like displacement amplitudes due to harmonic loading.

As an industrial example, the paper shows an engine bracket, where starting from the available design space and realistic loading and boundary conditions a topology optimization generates a design. This design is directly used for re-meshing and subsequent shape optimization to optimize weight and endurance related quantities. Analysis, optimization, and result evaluation are performed with an industrial FEA code (PERMAS with VisPER).