不同温度下MDYB-3有机玻璃的棘轮效应

对在不同温度和应力状态下, MDYB-3有机玻璃的棘轮效应进行了实验和分析.运用棘轮应变与应力-应变滞回环能量的对应关系和高聚物塑性变形的应力促进热激活理论,建立了一种新的适用于高聚物材料的稳态棘轮应变增长率的计算模型,揭示了温度、载荷频率、平均应力和应力幅值对棘轮应变演化的影响.将该模型应用于不同温度下MDYB-3有机玻璃疲劳过程中的棘轮变形增长行为的描述,理论预测结果与试验结果吻合良好.

Ratcheting Characteristic of MDYB-3 PMMA under Different Temperatures

The ratcheting behaviors of MDYB-3 PMMA during the fatigue under different temperatures were experimentally investigated. The theory of thermally activated yielding for polymer was used to describe the plastic deformation during the cycle. A new cyclic creep model was established based on the correlation between creep strains and hysteretic loop energies, which disclosed the influence of temperatures, loading frequency, mean stress and amplitude of stress on the evolutions of ratcheting strains. The suggested model was used to describe the accumulated rate of ratcheting strain under various temperatures and loading states, the predictions agreed well with experimental results.