屈强比对裂纹板极限强度的影响

摘要

工程上很重要的具有小裂纹板的极限强度却没有得到研究者的重视。文章首先对不同屈强比具有中心穿透裂纹的板进行了系列弹塑性有限元计算，结果表明板的极限强度随裂纹长度的衰减趋势可以分为两个阶段，而这两个阶段的范围并不是固定的，它们与板材的屈强比有着密切的联系。然后详细讨论了双向加载对裂纹板极限强度的影响，并对这些现象进行了合理解释。最后对这些计算结果进行了回归得到经验计算公式并将公式计算结果与实验结果及有限元结果进行比较，表明文中提出的公式具有较好的精度。%Because the investigations on the ultimate strength of a plate with small size crack, which is more important for the practice engineering, is not sufficient. The ultimate strengths of cracked plates with dif-ferent yield-tensile ratio were calculated using elastic-plastic finite element method. The FEA results show that the trends of the ultimate strength of a cracked plate declined with the increase of the length of the crack and can be divided into two parts. The separation points are different for different yield-tensile strength ratios of the plate materials. Then, the effects of the biaxial loads on the ultimate strength of cracked plate were studied in detail, and a reasonable explanation of these phenomena was given. Formulas for calculat-ing the ultimate strength of cracked plate are obtained based on the FEA results. The calculated results by the formula are compared with the corresponding experimental results and the FEA data, the comparison shows that the formula can give good precision results.