Design approach for automated transverse leaf spring composite structures in a suspension system

Abstract

Developing sustainable products using high persistent and durable materials is challenging. Associated processes to mature innovations in industrial development are often inflexible due to safety reasons and economic requirements. A possible approach to solve these challenges can be found in digitalized development processes. By using optimization techniques for automated evaluation, a high number of structural concepts can be created. The introduced optimization approach focuses on a virtual process chain for the automated design of glass fiber reinforced transverse leaf springs. Composite materials have the potential to reduce weight by functional integration and improved fatigue performance. As reference suspension system an innovative McPherson-like front suspension system is used. The control arms, coil springs and stabilizer bar are substituted by a composite leaf spring with the main goal to integrate wheel controlling functionalities into the structure. Parameters for wheel control are shape, fiber orientations and laminate lay-up. Designing composite transverse leaf springs with wheel controlling functionalities is extremely challenging due to obtained high number of design parameters. Large deflections due to wheel travel by preserving longitudinal and lateral stiffness and strength also complicate the identification of solutions in the design space. Therefore automation in modelling and evaluation is essential for using the required optimization algorithms. Meta-model-based, evolutionary or gradient optimization methods can be used to identify solutions in the obtained complex design space. The process chain connects CAD, finite element and multi body simulation software within the developed process chain. To ensure elastic behavior and durability, the Puck criterion is applied as an optimization constraint. The first results show that the investigated optimization approaches have high potential for finding appropriate composite structures with wheel controlling functionalities.