earticle

영어

In this study, Piezoelectric (PZT) sensors were used for the damage detection of beam. A simple cantilever test was conducted for the measurement of sensitivity of PZT. Free vibration test was done for the cantilever test in which the tip was displaced by weight and released. A simple H-beam test specimen that has bolted splice was built for the simulation of crane girder damage. The loosened bolt was assumed as a damage of splice. The healthy structure means that all bolts were tightened by torque wrench following specified torque. The test results of PZT sensor for the healthy structure were used as reference values and compared with those of damaged structure. The impact load was applied using Schmidt hammer for constant impact at the location of one-sixth point of beam span, The voltages from PZTs were converted to FFT data and the frequency change and magnitude were inspected to identify the damage. The basic data to identify the damage of crane girder were suggested based on the frequency change and magnitude ratio for the different modes.