181 / 2019-09-10 21:00:35

Stress relaxation of γ-radiation induced silicon rubber foams based on multi-scale simulation method

计算流体力学、多场耦合、生物力学、动力学等 > 多尺度建模与分析

The present work investigates γ-radiation dependence of the stress relaxation behaviors of silicon rubber foams by utilizing a developed multi-scale simulation method. Based on the real micro-porous structures of the silicon rubber foams, the ideal physical model is setup, where the pores with the same size are evenly distributed in the model. Therefore, the physical model can be constructed by stacking unit cells, i.e., micro-scale model. The hyper-elastic and visco-elastic constitutive models of the silicon rubber are setup based on the testing data, considering the different radiation doses (0, 150kGr, 300kGr, 500kGr). The stress relaxation of the micro-scale model is simulated when applying uniaxial compression strain. Results of the micro-scale model reveal that the compressive stresses decay monotonously with the time. Transferring the mechanical behaviors of the micro-scale model into the macro-scale models, the stress relaxation responses of the macro-scale models are numerically obtained. With the dose increasing, the compressive responses of the macro-scale models increase, and the stresses decay monotonously with the time as well. The ratios of long-time and initial stress are all above 85% in all cases. The simulation data coincide with the testing data very well, which verifies the simulation method developed in the present work.