超音波法於支撐鋼管材料受疲勞載重之安全評估

• Main Authors: Huan-Chin Wang, 王奐欽
• Other Authors: 劉佩玲
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/57600259737606196347

碩士 === 國立臺灣大學 === 應用力學研究所 === 94 === This work makes use of ultrasound detection method to identify fatigue damage in steel tubes caused by cyclic loading. From characteristic changes in the ultrasonic wave, we attempt to determine the safety lifespan of steel tubes that are common used as support frame in construction sites. By analyzing the change in phase velocity, we found that with increasing uniform cyclic compressional loading, the critical buckling load of the tube undergoes plastic hardening and strength of the tube increases. If the loading continues, the tube starts to weaken. We start by using the theoretical analysis of wave propagation in tube to verify the results of our experiment, following this; we further verify our experimental results using simulation results obtained using finite element analysis software, ANSYS. From the experimental result, we devise a method to evaluate the safety of steel tube by analyzing the change in phase velocity, improving the safety standards of supporting frame.