玻璃短纤维增强树脂基复合材料的单轴时间相关棘轮行为实验研究

Experimental study on uniaxial time-dependent ratcheting of short glass fiber reinforced polyester resin matrix composites

对玻璃短纤维增强树脂基复合材料(短纤维体积分数:28%,40%)的室温单轴循环棘轮行为进行了实验研究,讨论了复合材料在不同加载条件下的棘轮变形特征。结果表明:该复合材料在宏观层次上表现出与基体相类似的棘轮变形规律,即在非对称应力循环下也将产生明显的棘轮变形,并随应力幅值和平均应力的增加而增加;树脂基复合材料的棘轮行为具有明显的时间相关特性,棘轮应变值依赖于应力率和峰值保持时间。在建立玻璃短纤维增强不饱和聚酯树脂基复合材料棘轮行为的本构模型时必须考虑基体的黏性变形特征。

The uniaxial ratcheting of short glass fiber reinforced polyester resin matrix composites was studied experimentally at room temperature.The ratcheting behaviors of the composites were discussed under different conditions.It is shown that the ratcheting behavior of the composites is similar to that of the un-reinforced matrix in macro-scale,namely,the ratcheting also occurs in the composites under asymmetrical stress cycling,and the ratcheting strain increases as the stress amplitude and mean stress increase;the ratcheting has great time-dependence,i.e.,the ratcheting strain depends on the stress rate and peak stress hold time.It is concluded that the viscous deformation of the matrix should be involved in constructing a constitutive model for the ratcheting of the composites.