Many plastics show necking and drawing behavior in tension, sometimes called “cold drawing”. In contrast, elastomers stretch homogeneously in tension. We examine the tensile behavior of rubber–plastic laminate composites using 3D finite element simulations and an analytical model. A rate-independent constitutive behavior was adopted in which the modulus at small-strain, strain hardening at large strain, and yield stress (only for the plastic) can all be varied independently. For sufficiently small rubber/plastic thickness ratio, layered composites show necking and drawing wherein a tensile bar coexists in two strain states, one with a large stretch (necked region) and the other with a modest stretch (unnecked region). With increasing rubber/plastic thickness ratio, the two strain states approach each other in a manner resembling a second order phase transition culminating in a critical point. Above this critical rubber/plastic thickness ratio, the layered composites stretch homogeneously. An analytical model based on adding the First Piola–Kirchoff stresses of the rubber and plastic layers, along with a modification for inelastic deformation, is shown to capture most of the results of 3D simulations accurately. We comment on the practical relevance of these results to toughening relatively brittle plastics, and more specifically, the critical importance of strain hardening of the rubber.

许多塑料在张力下表现出颈缩和拉伸行为，有时也称为“冷拉伸”。相反，弹性体在张力上均匀地拉伸。我们使用3D有限元模拟和分析模型来检验橡胶-塑料层压复合材料的拉伸性能。采用与速率无关的本构行为，其中小应变时的模量，大应变时的应变硬化和屈服应力（仅对于塑料而言）都可以独立变化。对于足够小的橡胶/塑料厚度比，层状复合材料显示出颈缩和拉伸，其中拉伸杆以两种应变状态共存，一种具有较大的拉伸度（颈缩区域），而另一种具有适度的拉伸度（未颈缩区域）。随着橡胶/塑料厚度比的增加，这两个应变状态以类似于第二级相变的方式彼此接近，最终达到临界点。在该临界橡胶/塑料厚度比之上，层状复合材料均匀地拉伸。显示了一个基于添加橡胶和塑料层的第一Piola-Kirchoff应力以及非弹性变形的修正模型，可以准确地捕获大多数3D模拟结果。我们评论这些结果对增韧较脆的塑料的实际意义，尤其是对橡胶进行应变硬化的重要性。显示了一个基于添加橡胶和塑料层的第一Piola-Kirchoff应力以及非弹性变形的修正模型，可以准确地捕获大多数3D模拟结果。我们评论这些结果对增韧较脆的塑料的实际意义，尤其是对橡胶进行应变硬化的重要性。显示了一个基于添加橡胶和塑料层的第一Piola-Kirchoff应力以及非弹性变形的修正模型，可以准确地捕获大多数3D模拟结果。我们评论这些结果对增韧相对脆性塑料的实际意义，尤其是对橡胶进行应变硬化的至关重要性。