Abstract Nearly incompressible rubber-like materials, such as silicone adhesives, exhibit two failure modes: dilatational and distortional failure. The former corresponds to the formation and growth of cavities owing to triaxial deformation. The latter corresponds to fracture due to excessive isochoric deformation, i.e. deformation at constant volume. Both failure modes are typically assessed individually and corresponding failure criteria are often formulated in terms of stresses. However, stress-based descriptions of failure depend explicitly on the choice of constitutive law and the experimental measurement of critical stresses is challenging or even impossible. Therefore, recent studies proposed strain and stretch-based criteria for distortional failure of nearly incompressible hyperelastic materials, that can be obtained directly from optical measurements using digital image correlation. The present work exploits stretch-based descriptions of both failure modes to provide a unified coupled dilatational-distortional failure criterion which describes the complete failure surface of nearly incompressible silicone adhesives or rubber-like materials in general. For this purpose, we propose a stretch-based cavitation criterion which depends on a single parameter. Distortional failure is described by the Podgorski-criterion formulated in principal stretch space. The coupled dilatational-distortional failure criterion is validated using uniaxial tension, bulge and pancake tests of the nearly incompressible hyperelastic transparent structural silicone sealant DOWSIL™ TSSA. It is shown that the proposed failure criterion captures both the onset of cavitation and ultimate distortional failure in very good agreement with all experiments.

中文翻译：

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硅酮胶粘剂的耦合变形-膨胀失效模式概念

摘要 几乎不可压缩的类橡胶材料，如有机硅粘合剂，表现出两种失效模式：膨胀失效和扭曲失效。前者对应于由于三轴变形引起的空腔的形成和生长。后者对应于由于过度等容变形（即恒定体积下的变形）引起的断裂。两种失效模式通常单独评估，相应的失效标准通常根据应力制定。然而，基于应力的失效描述明确取决于本构定律的选择，并且临界应力的实验测量具有挑战性甚至不可能。因此，最近的研究提出了基于应变和拉伸的几乎不可压缩超弹性材料的变形破坏标准，可以直接从使用数字图像相关的光学测量中获得。目前的工作利用两种失效模式的基于拉伸的描述来提供统一的耦合膨胀-扭曲失效准则，该准则描述了几乎不可压缩的有机硅粘合剂或一般橡胶类材料的完整失效表面。为此，我们提出了一种基于拉伸的空化标准，该标准取决于单个参数。扭曲失效由在主拉伸空间中制定的 Podgorski 标准描述。使用几乎不可压缩的超弹性透明结构有机硅密封胶 DOWSIL™ TSSA 的单轴拉伸、膨胀和煎饼测试来验证耦合的膨胀-扭曲失效准则。