带有周期性裂纹薄膜热弹性场模拟研究

Numerical Simulation of the Thermal Elastic Field of the Thin Film with Periodic Cracks

通过建立带有周期性裂纹缆索薄膜/基底二维平面模型,分析不同参数对薄膜热弹性场的影响。运用有限元软件分析了在温度荷载作用下不同薄膜/基底弹性模量比、热膨胀系数对薄膜位移场、应力场的影响并且与理论值进行对比。结果表明有限元模拟结果与理论预测结果吻合良好,以上因素变化对薄膜轴向位移、轴向应力有明显的影响。薄膜表面位移和拉应力随着薄膜/基底弹性模量比与薄膜热膨胀系数的增大而增大,基底会对薄膜的热弹性场起到限制作用,边缘效应也会对薄膜热弹性场起到影响。理论值在薄膜与基底弹性失配较小或在薄膜边缘处不能准确的预测实际值。

A two- dimensional（ 2D） plane model of the cable film/substrate system with periodic cracks was established to study the influence of different parameters on the thermal elastic field. The displacement field and stress field of film/substrate system was analyzed under the influence of different elastic modulus ratio,thermal expansion coefficient with FEM. The results showed that the variation of the above factors has significant effect on the axial displacement and axial stress. The finite element simulation results are in good agreement with the theoretical predication. The surface displacement and tensile stress of film increase with the increasing of the film /substrate elastic modulus ratio and thermal expansion coefficient. The substrate and edge effect plays a restrictive role in thermal elastic field in the film. The theoretical value,at the place where the elastic mismatch of the film with the base is small or at the edge of the film,can not accurately predict the actual value.