Fuzzy Comprehensive Evaluation Of Weld Defects In Highway Steel Bridges With Ultrasonic Testing

For more than ten years,steel structures in highway bridge steel field is used widely, thewelding is the main connected way of the steel structure, so the performance of weldingcomponents related to the quality of the structure whether good or not. To do nondestructivetesting of welding structure, found defects timely and accurately, qualitative and quantitativedefects, then for the welds of not comply with the design requirements are repaired, and canguarantee the safety of the structure and service life.This paper summarizes the types and the causes of weld defects, and summarizes themeans and principles of magnetic powder detection, ray detection and ultrasonic detectioncommonly used to steel structure welding and summarizes the technical key operation of thethree detections. Combined with highway steel structure weld testing examples, worked out asuitable way for highway bridge steel weld detection, because of ultrasonic testing highefficiency,today it become the principal means of detection in construction steel structure.The undetected or misjudge problem of on testing by ultrasonic waves of welding seamis a very conspicuous problem.One of the important causes is that our judgment has deviationwhen we determine the size,shape and property of the reflected waves.Therefore,pointing tothe above situation,we do roundly systematic analysis about the very conspicuous problem inthe testing by ultrasonic waves of welding seam.We carry on roundly in-depth discuss fromthe genesis of the defects to rational choice of the crack detection measure.In this paper, utilizing the fuzzy comprehensive evaluation of weld defect levels to assesscan fully consider the impact of various factors, division level more reasonably,and providea new idea for the assessment of highway steel bridge weld defects, the practice has provedthat the fuzzy comprehensive evaluation applied to the weld defect assessment have a highconformity degree, and provide greater accuracy and security for the rating of highway steelbridge weld defects, and for related engineering inspections has a positive significance.