This paper presents an experimental investigation about the effect of elevated temperature on the mechanical properties of two polyurethane (PUR) foams, with densities of 40 kg/m³ and 93 kg/m³. The experimental campaign included shear and compressive tests over a temperature range of 20°C–200°C, performed to assess the degradation of the mechanical properties of the PUR foams with temperature. To validate the diagonal tension shear test method adopted in this investigation, a numerical study was also performed, namely to assess the (shear) stress state developed within the foam. The results obtained validated the adopted test procedures, showing that the compressive and shear responses are strongly affected by elevated temperature, due to the softening of the polymeric material when it undergoes the glass transition process. For the temperature range considered in this study, both strength and modulus in shear and compression present an approximately linear reduction with temperature.

本文介绍了关于升高温度对两种密度分别为 40 kg/m ³和 93 kg/m ^{3 的}聚氨酯 (PUR) 泡沫机械性能影响的实验研究. 实验活动包括在 20°C-200°C 的温度范围内进行剪切和压缩测试，以评估 PUR 泡沫的机械性能随温度的下降。为了验证本研究中采用的对角拉伸剪切试验方法，还进行了数值研究，即评估泡沫内产生的（剪切）应力状态。获得的结果验证了所采用的测试程序，表明压缩和剪切响应受高温的强烈影响，这是由于聚合材料在经历玻璃化转变过程时会软化。对于本研究中考虑的温度范围，剪切和压缩的强度和模量均随温度呈近似线性下降。