固体物料应力松弛特性的研究

A Study on the Stress Relaxation Properties of Solid Materials

通过萝卜的应力松弛试验,得出萝卜在不同加载速率、不同方向取样时的流变学参数:松弛应力、松弛模量和松弛时间,从而得出应力松弛曲线。其松弛模量随加载速率的增大而减小,径向取样时这种变化比轴向更为明显。在同一加载速率下,轴向试样比径向试样松弛时间短。因此建立用四单元Maxwell模型来描述萝卜的应力松弛现象,为机械设计及鉴定品种质量提供了理论依据,为预测机械损伤、提高产品质量、探索新的控制方法和判断依据提供最佳参数。

Rheological parameter(relaxation stress,relaxation modulus and relaxation time) under different loading rates and different directions of sampling were measured through a stressrelaxation test with a radish piece.The stress relaxation curve was obtained,which shows that relaxation modulus is decreased in magnitude with an increased loading speed rate.The variation of sampling at diametral direction was greater than sampling at axial direction.At the same rating speed rate,the relaxation time of the sample taken at axial direction was shorter than the sample taken at diametral direction.A fourunit generalized Maxwell model was set up graphically to express stresstime relationship for the radish.It provided theoretical basis for mechanical design and quality identification.Moreover it provided the optimum parameters for predicting mechanical damage,improving products quality,exploring new control method and judgment basis.