摘要:
结合钢箱梁局部模型试件,针对顶板角焊缝处表面裂纹进行钻孔止裂,进行止裂孔孔周应力计算,分析了不同孔位对止裂效果的影响并提出了合理止裂孔位,最后结合实际工程中止裂孔孔径应用情况,研究了合理止裂孔位与孔径的关系.分析结果表明,止裂孔没有改变构件整体应力变化趋势,孔边存在很大的应力降,但有应力台阶现象;孔位在0.5D(D为孔径尺寸)更远后,裂尖与孔边之间出现高应力、大应力降连接段,合理止裂孔位为0.5D,孔径大小对合理孔位与孔径的系数没有影响;止裂孔在裂纹尖端外情形下,孔径较小时,最大应力点还在裂纹尖端,孔径较大时,最大应力点在裂纹侧孔边,且离裂纹尖端越远,孔两侧最大应力差越小.%On a partial model of a steel girder bridge deck, surface crack near fillet weld was repaired by retrofit holes. Stress near the hole edge was calculated, and impact of the hole location was analyzed, Moreover, the best hole location for crack arrest was put forward. Considering the diameters of retrofit holes used in repairing engineering, the relationship between reasonable location and diameter of retrofit hole was studied. Analysis results indicate that retrofit hole does not change the global stress distribution, stress drop presents near hole edge and stress stair was found. When the distance from hole location to crack tip was larger than 0 . 5 D ( D stands for the diameter of the hole) , high level stress and large stress drop appear between crack tip and hole edge. The reasonable location was 0. 5D from crack tip, and the diameter has no influence on the reasonable hole location. When retrofit hole locates away from crack tip, maximum stress appears at the crack tip in the case of small retrofit hole whereas maximum stress appears at hole edge near crack side in the case of large retrofit hole. The farther the retrofit hole locate from crack tip, the smaller the stress difference between two sides of the hole becomes.