模态法辨识针刺C/ C 复合材料弹性模量

针对传统方法测量C/ C 复合材料弹性模量精度差问题,提出了一种利用模态试验辨识材料弹性模量的新方法。数值仿真结果表明板件材料振动频率与弹性模量之间存在模糊对应关系,利用此关系采用二分法及二阶响应面近似模型对材料弹性模量进行辨识,并分别利用各向同性薄壁板件及正交各向异性薄壁板件对此方法进行验证,计算结果误差最大为16. 67%,最小仅为0. 5%,表明该方法准确有效。最后将其应用于针刺C/ C 复合材料,获得了其弹性模量。仿真及试验结果均表明该方法无损、高效且准确度高。

Inverse Method Based on Modal Test for Characterizing

In order to solve the problem of poor precision for measuring C/ C composite elastic constant by traditionaltest method, the present paper provided a new method for obtaining the main elastic constants from modal test.According to the modal test data and the relationship between vibration frequencies and elastic constant, the scope ofthe elastic constants were estimated preliminarily. Then the quadratic response surface approximate model about elasticconstants and vibration frequencies was established to optimize the elastic constants. The isotropic and orthotropicthin plates were used to verify this method. The results show that the maximum error is 16. 67%, the minimum is only0. 5%, so the method is accurate and effective. At last, the elastic constant of needled C/ C composite is obtainedthrough the present method. The simulation and experimental results proved that the method is nondestructive,efficientand accurate.