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

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.