高强螺栓止裂法修复含裂纹钢板疲劳受力性能

Fatigue Performance of Cracked Steel Plates Repaired by High Strength Bolt Stop-hole Method

摘要:

为了分析高强螺栓止裂法的止裂效果，首先基于带裂纹钢板的有限元模型探究孔径和螺栓预紧力参数对修复后钢板的应力分布和止裂机理的影响。随后对修复后的预裂钢板进行3组对比疲劳试验，评价了不同修复方法下的结构疲劳寿命，并与各国规范相关S-N曲线进行比较。分析和试验结果表明：采用止裂孔法和高强螺栓止裂法均能延长损伤钢板的疲劳寿命，但高强螺栓止裂孔修复效率更优，其延长结构寿命是单纯止裂孔修复的9倍以上。以测点应力发生突变为疲劳失效判据时，单纯采用止裂孔修复不足以满足各国规范规定的疲劳强度等级，而高强螺栓止裂孔修复组明显高于AASHTO中A类细节等级，具有优异的抗疲劳性能。

Abstract:

Based on the finite element model of cracked steel plates， the influences of drilling-hole diameter and the pre-tightening force on the stress distribution and the crack arrest mechanism of the repaired steel plates are investigated to analyze the crack arrest effects of high strength bolt stop-hole method. After the pre-cracked steel plates were repaired， three groups of comparative fatigue tests were carried out to evaluate the fatigue life of the structures under various repair methods， and compared the test data with the relevant S-N curve provided by national codes. Analysis and test results indicate that two repair methods can prolong the fatigue life of the damaged steel plates， but the repairing efficiency of high strength bolt stop-hole repair method is better. Moreover， its fatigue life is over 9 times that of the steel plates by the only stop-hole repair method. According to the stress change criterion， to employ the stop-hole repair alone is not enough to satisfy the fatigue strength category specified by national standards， and the high-strength bolt stop-hole repair group is significantly higher than the category A of AASHTO， which has excellent fatigue resistance.