真空热循环对单向M40J/5228A复合材料质损率和线膨胀系数的影响

对单向M40J/5228A复合材料进行了真空热循环试验 ( 93~413 K,10-5Pa)。分别测试了经不同次数真空热循环后材料的质损率及线膨胀系数。通过所建二维细观损伤模型分析了真空热循环次数对材料线膨胀系数曲线影响的原因。试验结果表明,随真空热循环次数的增加,质损率增大,并经约48次真空热循环后趋于平缓;横向线膨胀系数随温度升高而线性增大,真空热循环次数对其没有影响;纵向线膨胀系数在原始状态时随温度升高而线性减小,经113次真空热循环后表现出先下降后上升的非线性特征,真空热循环次数对纵向线膨胀系数的影响,与界面脱粘程度和残余应力的消除密切相关。 

EFFECT OF VACUUM THERMO-CYCLING ON MASS LOSS AND LINEAR EXPANSION COEFFICIENT OF UNIDIRECTIONAL M40J/5228A COMPOSITE

The vacuum thermo-cycling tests (93~413 K, 10-5Pa) were carried out on the unidirectional M40J/5228A composite. The mass loss and linear expansion coefficient of the specimens were measured after vacuum thermo-cycling of different cycles. The effect of vacuum thermal cycles on the linear expansion coefficient profile was analyzed using a proposed two-dimensional model of micro-damage. The results show that the mass loss rate increases with increasing the vacuum thermal cycles, and becomes flat after 48 cycles; the transverse expansion coefficient linearly increases with increasing temperature, and is not affected by vacuum thermal cycles. The longitudinal expansion coefficient linearly decreases with increasing temperature under the original state, while it exhibits a non-linear characteristic of decreasing firstly and then increasing with temperature after 113 cycles. The effect of vacuum thermal cycles on the longitudinal linear expansion coefficient closely depends on the breaking extent of the binding interface and the relief of residual stress.