Crash Performance Increase with Structural BETAFOAM

The choice of the right material and joining technique in the modern BIW-Design is driven by several factors. The international competition between the OEM’s, new legislations concerning crashrequirements and the current development of fuel prices and the related customer interest in lower gas-consuming cars are just a few to be named. Even if we see from representatives from almost every material category – the full steel car body is still dominating. What has remarkably changed here is the move towards high- and highest-strength steel and “bake hardening”-grades. A stiff and homogeneous body is the baseline for a car with excellent driving behavior and pleasant acoustical performance. The BIW-Designer is combining the following principles to meet flexural and torsion stiffness requirements: • • • • • Build longitudinal and cross-car beams and useful profiles The use of high-strength steel grades and/or “Tailored Blanks“ Optimization of joining technologies Avoid structural weak spots like hinges and profile constrictions Local reinforcements of surfaces and profiles In addition, there is also the need to have an optimal performance of the body under the various load cases during a full car crash: Useful energy conversion in the profiles and rails while retaining the passenger compartment integrity. These design goals need also to be aligned with light-weight criteria. Future requirements concerning crash-performance and light weight needs will increase the demand for new materials and joining technologies. This article will discuss the opportunities to fulfill these requirements using polyurethane-foam based local reinforcements.