由图5所示，初始时刻裂纹张开位移沿x轴呈对称分布，其中在 处位移最大，l越小，裂纹张开位移越大。考虑到l是通过影响 进而影响裂纹张开位移，因此，在模型中选择合适的l值可以减小裂纹张开位移，延长材料的使用寿命。
图5裂纹张开位移随坐标x的变化
Fig.5Variationsofcrackopeningdisplacementswiththecoordinatex
图6最大裂纹张开位移随l的变化
Fig.6Variationsofthemaxcrackopeningdisplacementwithl
图6显示的是在初始时刻，最大裂纹张开位移随l的变化。对于不同的裂纹位置，随着l的增大，裂纹张开位移迅速减小后趋于稳定，当 时变化很明显。和图3中应力强度因子的变化曲线相似，裂纹张开位移的三条曲线在 处也近似交于一点。但是，这三条曲线差别很小，说明裂纹位置对裂纹张开位移的影响不大。
图7最大裂纹张开位移随时间 的变化
Fig.7Variationsofthemaxcrackopeningdisplacementwith
图7所示的是在不同的 影响下最大裂纹张开位移随时间的变化。材料的稳态模量和初始模量比值越大，裂纹张开位移越小。由于材料本身具有粘弹性，裂纹张开位移首先是增大趋势，随着时间的推移，裂纹张开位移因为载荷的减小而迅速减小。
4结论
（1）本文研究了介于两粘弹性均质材料之间的粘弹性FGM界面层反平面裂纹问题，通过引入两均质材料松弛模量时间因子比l，给出了FGM界面层一种广义剪切松弛模量，这比已有文献中的松弛模量更具有一般性。
（2）由Fourier变换推导了反平面裂纹问题的奇异积分方程，通过数值计算首先得到应力强度因子和裂纹张开位移的弹性解，再根据FGM的粘弹性对应原理和Laplace变换得到粘弹性解。
（3）分析了两均质材料松弛模量时间因子比l、裂纹位置等参数对应力强度因子和裂纹张开位移的影响。发现l通过影响FGM等效非均匀性参数而影响应力强度因子和裂纹张开位移。裂纹位置对应力强度因子有显著影响，而对裂纹张开位移影响不大。
（4）本文给出的广义剪切松弛模量可应用于不同类型的裂纹在平面或轴对称等问题中的求解，这对于FGM的粘弹性对应原理在实际中的应用具有一定的价值。
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