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原文传递 Guidelines for Ultrasonic Inspection of Hanger Pins.

题名：	Guidelines for Ultrasonic Inspection of Hanger Pins.
作者：	moore, m. phares, b. m. washer, g. a.
关键词：	pins,ultrasonic testing,inspection,bridge hanger pins
摘要：	A failed hanger pin initiated the tragic collapse of one span of the Mianus River Bridge in Greenwich, CT on June 28, 1983, resulting in the deaths of three motorists. Following the collapse, there was an immediate increase of interest in the inspection and condition evaluation of bridge hanger pins. Ultrasonic inspection has become the primary method of performing detailed inspection of in-service hanger pins. The document describes the fundamentals of ultrasonic testing and general inspection requirements that can be used by State transportation agencies or by others performing ultrasonic hanger pin inspection. In addition, five hanger pins, with known defects, were inspected to emphasize and more completely explain some important aspects of ultrasonic hanger pin inspection. Items included in the fundamental review are the pulse-echo technique, pitch-catch technique, decibel scale, piezoelectric effect, beam diffraction, beam absorption, beam spread (beam divergence), beam centerline location, and distance amplitude correction. Items included in the general inspection requirement section are cleaning and coupling requirements, interpretation of signals, defect sizing techniques, effect of wear grooves, phenomena of acoustic coupling, inspection documentation, data collection, and inspector qualifications and certifications. Results from the experimental program include beam diffraction graphs, distance amplitude correction curves, sensitivity analysis of straight and angled beams, defect sizing analysis, and verification of the acoustic coupling phenomena.
报告类型：	科技报告