Under the service conditions of nuclear engineering applications, silicone rubber foams should endure radiation of γ rays accompanied by compression and shear loading. In this paper, the Hyperfoam model is extended to characterize the mechanical behaviors of silicone rubber foams under γ-irradiation. After exposing silicone rubber foams to a wide radiation dose range from 0 to 500 kGy at room temperature, uniaxial compression and simple shear tests were carried out to establish the relationships between the model parameters of Hyperfoam model and radiation dose, and indentation tests were performed to verify the extended Hyperfoam model. The linear radiation dose-related hardening properties of the material are derived using the testing results, including the linear increases of the initial shear modulus, and the compression stress and the shear stress for a given strain condition, which result in the linear radiation dose-dependent relationships for the initial shear modulus-related model parameters and the radiation dose-independent hardening exponent-related model parameters of Hyperfoam model. The performances of the extended Hyperfoam model are demonstrated by comparing the fitted material responses with uniaxial compression and simple shear data over the studied radiation dose range. And the prediction ability is verified by comparing the simulated results of indentation using the finite element method with the test data. The extended model is capable of characterizing the coupling stress state of compression and shear in the investigated irradiation dose range, which is expected to aid in evaluating the safety of nuclear engineering structures.

在核工程应用的使用条件下，硅橡胶泡沫应承受伴随压缩和剪切载荷的γ射线辐射。本文扩展了Hyperfoam模型，以表征在γ辐射下硅橡胶泡沫的力学行为。将硅橡胶泡沫在室温下暴露于0至500 kGy的宽辐射剂量范围后，进行单轴压缩和简单剪切试验，以建立Hyperfoam模型的模型参数与辐射剂量之间的关系，并进行压痕试验，验证扩展的Hyperfoam模型。使用测试结果可以得出材料与辐射剂量相关的线性硬化特性，包括初始剪切模量的线性增加，以及给定应变条件下的压缩应力和剪切应力，从而导致Hyperfoam模型的初始剪切模量相关模型参数和辐射剂量独立硬化指数相关模型参数具有线性辐射剂量依赖性。通过在研究的辐射剂量范围内将拟合的材料响应与单轴压缩和简单剪切数据进行比较，证明了扩展的Hyperfoam模型的性能。通过将有限元法压痕的模拟结果与测试数据进行比较，验证了预测能力。扩展模型能够表征研究的辐照剂量范围内的压缩和剪切耦合应力状态，