Nowadays, composite materials are playing an increasingly important role in material forming processes because they can combine remarkable physical and mechanical properties with relatively low weight. The main objective of this work is to study the forming behaviour of multi-layer sheets by finite element analysis. The possibility of replacing the composite by a single equivalent material, with a plastic behaviour similar to that of the composite, was also numerically analysed. This study focuses on two three-layer sheets, each composed of two metallic outer layers and a core of polymeric material; on one of the sheets, the outer layers are steel and, on the other, aluminium. Numerical simulations of the bulge test and of the deep drawing of a U-channel profile and a square cup were used to evaluate the behaviour of the multi-layer sheets and their equivalent materials. The influences of the difference of the mechanical properties of the constituent materials and some geometrical parameters of the deep-drawing process on the plastic behaviour, namely the curves of force vs. displacement of the punch and the strain and stress distributions, were evaluated. The possibility of using the bulge test to characterize the behaviour of the composite was also analysed.

中文翻译：

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多层板成形行为的数值研究

如今，复合材料在材料成型过程中起着越来越重要的作用，因为它们可以将卓越的物理和机械性能与相对较低的重量结合在一起。这项工作的主要目的是通过有限元分析研究多层板的成形行为。还数值分析了用单一等效材料代替复合材料的可能性，该材料具有类似于复合材料的塑性行为。这项研究的重点是两个三层板，每个板由两个金属外层和一个聚合物材料芯组成。在其中一层上，外层是钢，在另一层上是铝。凸出测试的数值模拟以及U形型材和方形杯的深冲的数值模拟用于评估多层板及其等效材料的性能。评估了组成材料的机械性能差异以及深冲过程的某些几何参数对塑性行为的影响，即冲头的力与位移曲线以及应变和应力分布。还分析了使用凸出测试表征复合材料行为的可能性。评估了冲头的位移以及应变和应力分布。还分析了使用膨胀试验表征复合材料行为的可能性。评估了冲头的位移以及应变和应力分布。还分析了使用凸出测试表征复合材料行为的可能性。