Headliner Trim Design Methodology Development with Finite Element Simulation and Optimization Considering Multi Domain Performance

Passenger cars in the top segment have seen fast growth over the last few decades with an increasing focus on luxury, convenience, safety and the quality of driver experience. The headliner is a decorative and functional trim system covering the underside of the roof panel. It enhances the aesthetics and elegance of the car interiors. In premium vehicles, the headliner system has to suffice interior quietness and integrity apart from the performance and regulatory requirements. The Design Validation Plan requirements cover its contribution to the vehicle interior noise control, occupant safety, and perception of build quality. Contributions can be very significant and primarily be determined by design and material parameters. Also, headliner interactions with an adjacent body in white structure are crucial from performance point of view. Various foam options are available with different functions such as structural, acoustic, and energy-absorption. Part thicknesses vary depending on the class of vehicle and respective demands. Foam locations and types greatly influence the proportional performance. Selection of each parameter in an efficient way is a critical task, as cost factor also plays an important role in decision making. Finite Element Method and optimization tools are used to setup the process for deriving design which meets performance characteristics by sequential process. The scope of this paper is to propose a suitable process for conceptual design for the headliner trim. Applicable load cases from NVH, durability, and IHI domain are considered during the development. To accelerate the process, linear problem definition is considered using equivalent static loading conditions. Different variables including part thickness, part material properties, foam properties, and foam locations have been considered. Proposed headliner design optimization process helped to find the efficient design with reduction in the development cycle time.