Evaluation of Steel Bridge Inspection Instruments:Acoustic Crack Detector (ACD)/Magnetic Crack Definer (MCD).

摘要

This report discusses the field testing and evaluation of a steel bridge inspection device developed for FHWA by the Southwest Research Institute and tested in cooperation with ten participating State highway departments including Connecticut,California,Montana,Idaho,Pennsylvania,Ohio,Georgia,Texas,Arkansas,and Virginia. The device was used on various types and ages of steel bridges ranging from wrought iron trusses to modern bridge steels. The study concluded that the disadvantages with conventional non-destructive test equipment have not been eliminated with the ACD/MCD system:that is,extensive operator training is still required,and little or no production rate of inspected members of bridges is feasible. The difficulties encountered in characterizing the ACD unit to the steel being surveyed would limit its practical use to indepth inspections by trained personnel of structural details susceptible to fatigue cracking on relatively new bridges. Cracks observed by visual inspection can be verified and defined on flat smooth surfaces by the ACD/MCD units.