玻璃态材料非线性流变:简化的Maxwell模型

玻璃态材料在不同的加载条件下,其力学行为表现出很大的差异性.该文提出了一个简化的Maxwell模型结合速率方程,研究了应变率、温度和老化时间对自由体积缺陷演化控制的玻璃态材料非线性力学响应的影响.研究表明,一定范围内应变率越大、温度越低、老化时间越长,应力峰值越大,且应力峰值和临界应变对于老化时间具有对数依赖性.这些结论与前人分子动力学模拟得到的结果相一致.

Nonlinear Rheology of Glassy Materials: a Simplified Maxwell Model

The mechanical behaviors of glassy materials show great differences under different loading conditions. A simplified Maxwell model combined with rate equations was proposed to study the influences of the strain rate, the temperature, and the aging time on the nonlinear mechanical responses of glassy materials controlled by the evolution of free volume defects. With this model, it is revealed that, within a certain range the higher the strain rate is, the lower the temperature, the longer the aging time and the higher the peak stress will be. In addition, the model also indicates that the peak stress and the critical strain of the stress strain curve exhibit logarithmic dependence on the aging time. These conclusions are consistent with the results previously reported out of molecular dynamics simulations.