弯矩作用下热塑性复合材料平面曲梁弹塑性特性分析

ELASTIC-PLASTIC ANALYSIS FOR THERMOPLASTIC COMPOSITE PLANE CURVED BEAMS BY BENDING MOMENT

热塑性复合材料综合力学性能优异,具有广阔的应用前景。针对弯矩作用下热塑性复合材料平面曲梁进行了静力学建模及弹塑性特性分析。根据极坐标系下平面应力问题的基本方程,基于单参数塑性模型、相关塑性流动准则以及线性应变强化规律,建立了曲梁的控制方程,得到了曲梁应力和位移的解析解。在此基础上,系统分析了曲梁几何尺寸对截面应力分布的影响,并结合Hashin失效准则对曲梁失效形式进行判断。结果表明,所建模型在研究热塑性复合材料平面纯弯曲梁弹塑性特性问题中准确有效,曲梁失效形式与径厚比密切相关。

Thermoplastic composites have excellent comprehensive mechanical properties and widely applied prospects.A static model was established and elastic-plastic characteristics were analyzed for a plane curved beam,which was made of thermoplastic composites and subjected to bending.Based on the single parameter plastic modal,the associated flow rules and the linear strain hardening law,the governing equations of curved beams were derived according to the basic equations of plane stress problem in polar coordinates.The analytical solutions of stress and displacement were then obtained.The influence of geometrical size on stress distribution at the cross-section of the curved beam was analyzed.Also,the failure mode of the curved beam was judged in virtue of the Hashin failure criterion.The results demonstrate the efficiency of the proposed model for elastic-plastic characteristics analysis of thermoplastic composite curved beams subjected to bending.And the failure mode of curved beams is associated with the radius-thickness ratio.