Analysis Of Defect Inspection On Cfst Bridges Based On Ultrasonic Wave Theory

Applying ultrasonic theory to CFST non-destructive detection(NDT) is a new type method which is recently emerged. It has a series of merits and received professional staff's attraction from many countries. Currently our country has draw up and established concrete defects ultrasonic detection technical code (CECS 21:2000) , in the chapter 10 it has specially introduced detective method for CFST material.The key point used for UT test in CFST is the wave time test, when the ultrasonic wave get through the CFST, it has two ways which are by the steel tube wall and by the CFST interior, usually speaking, the former is above the later. The CFST internal defect condition is reflected by the wave's variation. When the other condition is the same, wave time for ultrasonic wave pass through the good and the flaw CFST are different, this thesis is based on theoretical principle to start the research.This thesis has summarized formerly people's work and researched the spreading principle, then similarities and differences between the ultrasonic wave and ordinary wave. In Sanshan West Bridge arch's defect detection, we calculate the defect's dimension through analysis the wave time and wave shape parameters, and then verify the results by boring a hole. Analysis the CSFT arch's inner flaw after filled with serosity, the results show that flaw is fully filled. At last, we use the Origin 8.0 programme to carry out the data regression analysis. Simple linearity equation and curve equation is established. Then we discuss the coefficients of the two equation as calculate precision, standard deviation, related coefficient, error deviation. We suggest the linearity equation is the first choice.