Simulation of non-rigid products: An industrial application related to car soft top design

This paper addresses the problem of predicting the in-service behaviour of non-rigid product, i.e. the simulation of product functionalities under operating conditions within a Digital Mock-up. Think, for example, to the design of a car soft-top: while today, with the aid of common computer-based tools, it is rather simple to design and simulate the kinematic mechanism of opening/closure, it is not so easy to understand how it is influenced by the covering material. To this end we have used a commercial system for mechanism analysis and a tool, named SoftWorld, which permits to model and simulate the behaviour of non-rigid parts (sunroof fabric) taking into account material properties. SoftWorld adopts a particle-based model by which an object can be represented by a set of particles connected by forces describing the objects mechanical behaviour. Using the integrated environment we have studied and simulated the opening/closure mechanism of a convertible car soft-top integrated with covering materials behaviour.