有损伤简支桥梁的波动分析

Wave Analysis of Damaged Simple Bridge

大跨度桥梁这种大、轻、柔结构在承受扰动时,响应呈现明显的波动现象.出于对该类结构进行局部控制和健康安全监测的需要,应用回传射线矩阵法,对方波脉冲作用下的有损伤简支桥梁进行波动分析.桥梁结构的局部损伤用减小单元的杨氏模量来模拟.比较方波作用下有损伤结构与无损伤结构跨中处的弯矩波,研究损伤程度对弯矩波的影响.结果表明,当方波脉冲以力偶方式作用时,通过结构跨中处的弯矩波曲线能够准确的判断损伤存在,确定损伤位置和损伤区域.

A great deal of researches and experiments show that the response of long span bridge which is long, light, and flexible, is presented obviously wave phenomenon when it is disturbed by external force. For the sake of carrying on local control＇and health safety monitoring to this kind of structures, wave analysis is proceeded for the damaged simple bridge which is applied by square pulse. The damage is modeled as decreased Young＇s modulus. Comparison is made between the moment wave of damaged structure and nondestructive structure which are applied by a moment squre pulse. The results show that the moment wave of the span centre of the bridge can detect and locate the damage while the square pulse is applied by means of moment.