双轴向纤维增强复合材料层合板强度准则

Investigation of Strength Criterion for Biaxial Fiber-Reinforced Composite Laminated Plates

为了更加准确地对双轴向纤维增强复合材料在双向载荷作用下的强度进行预测,本文针对Tsai-Wu强度理论进行了理论分析和实验研究。首先,讨论Tsai-Wu张量准则在双向纤维增强复合材料中的应用问题,并确定用双轴拉伸实验来测定准则其中的一个强度参数F12。其次,采用数值模拟方法,结合Taguchi实验设计方法对十字形试件进行外形设计和参数优化,得到了中心应力水平高、过渡区域应力集中系数小的十字形试件。最后,对十字形试件进行不同载荷比的双轴拉伸实验,通过实验数据计算得到强度参数F12,并拟合了该材料应力平面第一象限的强度包络线。研究结果表明,经实验数据修正后的Tsai-Wu强度包络线能够准确地反映出材料的强度特性。

To predict the strength of biaxial fiber-reinforced composites under biaxial tensile loads more accurately, Tsai-Wu tensor criterion is studied through theoretical and experimental methods. Firstly, the applicability of Tsai-Wu tensor criterion in the field of biaxial fiber-reinforced composites is discussed and one of strength parameters in criterion F12 is defined by biaxial tensile experiment. Secondly, overall design and parameter optimization of cruciform specimen are performed by the methods of numerical simulation and Taguchi experiment, so a type of cruciform specimen with the properties of high stress level at central weak region and small stress concentration factor is designed. Finally, the specimens are tested by some biaxial tensile experiments at different loading ratios. Strength parameters F12 at different loading ratios are calculated by experimental strength date and the failure envelopes with different values of F12 are constructed in the first quadrant of the stress plane. The study shows that failure envelopes fitted by experimental strength parameters are much closer to the intensity properties of the composites.