单向纤维复合材料粘弹性性能预测

建立了基于均匀化理论的单向纤维复合材料粘弹性性能预测方法。对单向纤维增强复合材料粘弹性问题的控制方程进行Laplace变换,在像空间中利用均匀化理论建立宏观松弛模量的Laplace变换与微结构描述参数以及变换参数间的关系。用Prony级数模拟松弛模量随变换参数的变化形式,并根据像空间中一系列变换参数对应的松弛模量的数值,采用函数拟合技术确定Prony级数的形式,从而确定用显示形式表示的松弛模量的Laplace变换随变换参数的变化规律。对显式表达式的逆变换获得时间域内的松弛模量。该方法利用拟合函数的逆变换避开了复杂的数值Laplace逆变换,使单向纤维增强复合材料的粘弹性性能的确定变得容易。文中给出了单向纤维复合材料松弛模量的数值预测结果并同有限元法模拟试验的结果对比,验证了预测结果的准确性以及本文方法的有效性。

Prediction of visco-elastic property of unidirectional fiber reinforced composite materials

A homogenization-based method for predicting the visco-elastic property of unidirectional fiber reinforced composite materials is presented.After Laplace-transforming the governing equation of the viscoelastic problem of unidirectional fiber reinforced composite materials,the relaxation modulus in Laplace transformed space is obtained with homogenization method.The relation of transformed modulus with transformation parameter is expressed approximately in terms of Prony series by function fitness.Then the visco-elastic relaxation modulus in time space are obtained by the inverse Laplace transformation of the fitted function.The method takes advantage of function fitness and avoids complicated numerical inversion of Laplace transformation,which makes the prediction of visco-elastic relaxation modulus easy.Numerical prediction results of the visco-elastic modulus of unidirectional fiber reinforced materials are presented and compared with that obtained by finite element simulation.The comparison shows the predicted results are accurate and the present method is effective.