Integrating kinematics and physically-based simulation in a car sunroof virtual prototyping

In this paper we address the design of a complex mechanical system through a Digital Mock-Up; in particular we consider the design of a car soft-top. The main goal has been to predict the in-service behavior through the simulation of product functionalities under operating conditions within a Digital Mock-up. We verified the feasibility of models and techniques, independently developed and applied in different contexts, which can be appropriately integrated to study the considered mechanical system. We adopted and integrated multi-body techniques for the kinematics and dynamic analysis of the soft top mechanism and physically based techniques to model and simulate the fabric deformation when opening and closing the soft-top of a Volkswagen Golf Cabrio. We considered a commercial system for mechanism analysis and a tool, named SoftWorld, which permits to model and simulate the behavior of non-rigid materials and both off-line and integrated simulations have been performed. The research work has been conducted within the framework of the European Brite-Project DMU-FS (Digital Mock-Up – Functional Simulation).