复合材料叠层结构孔口附近应力分析方法研究

本文在总结前人对复合材料结构开口的应力集中研究的基础上,根据孔口附近应力场的特点,提出了一种适于工程应用的复合材料叠层结构开口附近应力分析的有限元改进算法。由于应力计算精度的改进仅在孔边、拐角等高应力梯度区域局部进行,且改进后的单元能进一步精确描述应力集中区的应力场。因而,使用该方法计算孔边应力,用较少的单元就能得到满意的精度,大大减少了计算费用和时间。 文中选择了一些有代表性的考题验证了该方法的有效性。并着重研究了带有圆角矩形孔的复合材料层板结构的孔边应力分布,给出应力集中系数随圆角半径的变化规律、孔边加强对应力集中的改善以及±45°纤维铺层比例对孔边应力分布的影响,得到了一些对工程部件开口设计有用的数据资料。

Research on the Method of Stress Analysis around Cutout in Laminated Structure

An engineering practicable method,which could improve the prediction for the stresses around the cutout in the composite laminated structures,is presented in this paper.The improvements for the stress prediction are implemented locally in stress concentration zones, such as cutouts and corners. The fields with high stress gradient around cutouts could be described more precisely by the improved elements.Therefore,the results with satisfactory precision could be obtained by using fewer elements, which leads to the decrease of computation expenses and time.Some typical examples are used to verify the effectiveness of the method. The variation of stress concentrations with radii of circular corners as well as the influence of the ratio of ?5?plies on the stress concentration are studied. Some data and results,which are useful for the designs of cutouts in laminated parts,are presented.