Tailored metal-polymer-metal layered composites for improved energy absorption characteristics of crash structures

由金属-聚合物-金属（MPM）层状复合材料制成的与碰撞相关的结构部件的变形和破坏行为强烈依赖于应变率相关的各层材料行为以及各层之间在高动态载荷下的粘附行为。在DFG项目“改善碰撞结构吸能特性的定制金属-聚合物-金属层状复合材料”中，开发了一种MPM层状复合材料混合碰撞箱的一致性建模与计算策略，并成功应用。定性地表明，粘附行为对结构行为和由此产生的能量吸收能力至关重要，并且可以通过有针对性的局部调整进一步增加。为此，必须制定方法和设计指南，以便有效地设置与碰撞载荷相关的MPM层复合材料性能。此外，合适的连接概念、成形过程引起的应变硬化和诱导残余应力对MPM结构碰撞行为的影响尚未得到充分的研究。基于所建立的MPM层复合材料的跨尺度建模和表征策略，所预见的项目将最终通过考虑成形和连接过程来预测局部可配置MPM层复合材料的碰撞行为。在此基础上，将开发定制能量吸收特性的设置程序。一方面，应增加结构的能量吸收，另一方面，应通过局部破坏机制具体影响结构的变形行为。

The deformation and failure behaviour of crash-relevant structural components made of metal-polymer-metal (MPM) layered composites is strongly dependent of the strain rate-dependent material behaviour of the individual layers and the adhesion behaviour between the layers under highly dynamic loads. In the DFG project "Tailor-made metal-polymer-metal layered composites for improved energy absorption characteristics of crash structures", a strategy for consistent modeling and calculation of hybrid crash boxes made of MPM layer composites was developed and successfully applied. It was shown qualitatively that the adhesion behaviour is essential for the structural one and the resulting energy absorption capacity and can be further increased by a targeted and local adjustment. For this purpose, methods and design guidelines have to be developed that enable an efficient setting of load-related MPM layer composite properties for crash-loaded structural components. In addition, the influence of suitable joining concepts, strain hardening caused by the forming process and induced residual stresses on the crash behaviour of MPM structures has not yet been sufficiently investigated. Based on the established cross-scale modeling and characterization strategy for MPM layer composites, the project foreseen will finally predict the crash behaviour of locally configurable MPM layer composites by considering the forming and joining processes. Based on this, procedures for setting tailor-made energy absorption characteristics will be developed. On the one hand, the structural energy absorption should be increased and, on the other hand, the deformation behaviour should be specifically influenced by means of local failure mechanisms.