White Papers

Simulating Computer-Controlled Multibody Dynamic Systems

Today’s increasingly sophisticated products often consist of a mechanical system controlled by a microprocessor-based control system. But creating virtual prototypes of these products using traditional simulation approaches is difficult for various reasons. Typically, a mechanical engineer can develop a good mechanical model using Multibody Dynamics (MBD) simulation software, but including an over-simplified control scheme in the model yields useless results. Meanwhile, a controls engineer can design a controller using control systems modeling software, but without a realistic model of the plant (the mechanical system), the controller design will be poor.

Recently, however, new technology has been created which allows simulation of both complex nonlinear mechanical systems and their controllers together. With this new technology, the control system designers can efficiently test pre-developed control algorithms at an early design stage with highly nonlinear dynamic models. And mechanical engineers can quickly simulate their models using the developed control systems before costly prototypes are built. To simplify the workflow, both types of engineers can make changes to separate parts of the same model.

Seamless Integration of Injection Molding and Structure Analysis Tools

The application of Computer Aided Engineering (CAE) analysis to injection-molded plastic parts has become popular in the recent years, especially for part structure design and molding process optimization. Users study the designs and experiments through numerous individual CAE tools. However, there are certain problems which arise from performing these analyses separately. Properties resulting from the molding process, such as fiber-induced anisotropic mechanical properties, might be not favorable to the final product and should somehow be included in the other analyses. In addition, the mesh requirements for different CAE analyses might be different.

In this paper, an integrated approach from design phase to manufacturing phase is proposed to seamlessly combine part structure analysis and injection molding analysis through related-data linking and mesh property mapping. This developed approach is proved through numerical experiments to be a cost-effective method for related part/mold designers.