MDYB-3有机玻璃疲劳性能温度效应研究

 对MDYB-3有机玻璃进行了不同温度下等幅载荷拉-拉疲劳试验，对实验结果按照疲劳寿命的幂函数公式进行拟合，得到了几个典型温度下的S-N曲线。结果表明随着温度的升高，疲劳强度有大幅度的降低。在对实验数据线性回归分析结果的基础上进行多项式拟合，建立了考虑温度效应的疲劳寿命估算方程，并用疲劳包络线粗略地表示了不同温度下达到指定疲劳寿命时的应力水平。分析了疲劳总应变与循环次数比之间的关系，给出了不同温度下第二阶段总应变增长率与疲劳寿命之间的关系式。研究结果为飞机风挡和舱盖的设计和寿命评估提供了参考和依据。

The Fatigue Performance of MDYB-3 PMMA Under Different Temperature

The fatigue behaviors of MDYB-3 PMMA(polymethyl methacrylate)in uniaxial tension under cyclic loading of constant amplitude at different temperatures are investigated experimentally.The S-N curves at the typical temperatures are obtained by fitting experimental data according to the fatigue power function.It is found that the fatigue strength decreases violently with the temperature increases.On the basis of the equations of linear regression at five experimental temperatures,the fatigue life assessment equation considering temperature effect is established using polynomial fitting method.The fatigue envelope lines roughly represent the stress levels at given life cycles under different temperatures.In addition,the relationships between the total fatigue strain and cycle ratio are analyzed,and the second stages of development of the strain at different temperatures are obtained,from which the fatigue life of PMMA can be predicted.The results of present investigation offer the basis and reference for the design and the life-evaluation analysis of aircraft windscreen and canopy.