Sandwich structures are widely used for the design and fabrication of lightweight structural systems, due to their capability to exhibit excellent structural and thermal performances at low material usage. Understanding the phenomena of propagation of macro-cracks in the core and delamination at the face-to-core interface are aspects of great computational interest. Linking sophisticated models with the actual characterisation of their mechanical properties is essential in view of real engineering applications. The elastic and fracture characterisation of the materials composing the core is particularly relevant because its cracking affects the capacity of the sandwich structures to carry out transverse loads. In this work, PVC foams typically used as the inner core in structural applications are investigated over a range of foam densities. Firstly, the elastic properties of foams under compressive uniaxial loading are measured using a full-field methodology. Subsequently, Semi-Circular specimens are tested in bending varying the position of supports to generate all range of mixed fracture modes. Suitable fracture criteria are also considered in order to assess their capability to evaluate fracture parameters in PVC foams. Finally, the parameters experimentally determined have been used to validate the response provided by a numerical model developed by the authors.

三明治结构由于其在低材料用量下具有出色的结构和热性能的能力而被广泛用于轻型结构系统的设计和制造。理解核中宏观裂纹的传播现象以及面对核界面处的分层是计算方面的重要问题。鉴于实际的工程应用，将复杂的模型与其机械特性的实际特征联系起来至关重要。组成型芯的材料的弹性和断裂特性特别重要，因为其开裂会影响夹层结构承受横向载荷的能力。在这项工作中，研究了在各种泡沫密度范围内通常用作结构应用中的内芯的PVC泡沫。首先，使用全场方法测量压缩单轴载荷下泡沫的弹性性能。随后，对半圆形试样进行弯曲测试，以改变其支撑位置，以生成所有范围的混合断裂模式。为了评估其评估PVC泡沫中的断裂参数的能力，还考虑了合适的断裂标准。最后，通过实验确定的参数已用于验证作者开发的数值模型所提供的响应。为了评估其评估PVC泡沫中的断裂参数的能力，还考虑了合适的断裂标准。最后，通过实验确定的参数已用于验证作者开发的数值模型所提供的响应。为了评估其评估PVC泡沫中的断裂参数的能力，还考虑了合适的断裂标准。最后，通过实验确定的参数已用于验证作者开发的数值模型所提供的响应。