Establishment of hyperelastic parameters and structural finite element simulation based on uniaxial tensile for silicone gel

To investigate the hyperelasticity of silicone gel, its mechanical properties were characterized by uniaxial tensile (UT) test in the temperature region of [−30℃, 30℃]. The stress-strain curves of silicone gel at different temperatures were obtained and found that the initial elastic modulus of silicone gel is positively correlated with temperature from −30℃ to 0℃ and negatively correlated with temperature from 0℃ to 30℃. According to UT experimental data, the selection strategies and parameter determination methods of in-built hyperelastic constitutive equations (Neo Hookean, Mooney-Rivlin, Yeoh, Arruda-Boyce, etc.) were discussed in the finite element simulation. Then based on the selected: Neo Hookean model, a temperature-dependent hyperelastic constitutive model was established to describe the stress-strain response of silicone gel over a wide temperature range. The temperature-dependent model was written using UHYPER subroutine of ABAQUS. In combination with Fiber Bragg Grating (FBG) monitoring technology, numerical simulation and experimental monitoring of silicone gel for typical encapsulation structures were carried out during high-low temperature cycles of [−30℃, 30℃]. The strain results at the observation points show that the final error between experimental measurement and numerical prediction is 7%, revealing the validity of the hyperelastic constitutive equation derived in this paper and its value in practical application.