Vibration Analysis of a Traveling Crack Beam

• Main Authors: Chia-Hung Chiu, 邱家宏
• Other Authors: Lien-Wen Chen
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/91312736347541875041

碩士 === 國立成功大學 === 機械工程學系碩博士班 === 91 === The objective of this dissertation is to study the vibration of a traveling crack beam. The Hamilton’s principle and the finite element method are employed to derive the finite-element equations of motion for the traveling crack beam. The governing matrix equation for vibrations of the crack beam is constructed from the basic standard beam elements combined with the modified line-spring model. The regions of dynamic instability are determined by Bolotin’s method and the state space method. From numerical calculations, the results show that the natural frequencies can be affected by the crack depth and location. The effect of crack position is found to be the most significant, when the crack is at the point with the steepest slope of the uncrack mode shape. The speed of the traveling beam can reduce the natural frequencies and the critical speed.