运用曲率模态技术的木梁损伤定量识别  

Quantitative Identification of Wood Beam Damage Using Modal Curvature Theory

作　　者：徐华东[1] 王立海[1] 胡志栋[1] 

机构地区：[1]东北林业大学工程技术学院,哈尔滨150040

出　　处：《振动．测试与诊断》2011年第1期110-114,132-133,共5页Journal of Vibration,Measurement & Diagnosis

基　　金：国家自然科学基金资助项目(编号:30671643);国家"十一五"科技支撑项目(编号:2006BAD18B07);东北林业大学优秀博士学位论文培育计划;中央高校基本科研专项资金资助项目(编号:DL09CB01)

摘　　要：为对木结构构件局部缺陷进行有效检测,结合试验模态分析和有限元模拟方法,对含不同位置、大小和数量孔洞缺陷的木梁进行研究,计算其第1阶位移模态振型和曲率模态,分析木梁损伤前后的曲率模态变化,探讨模态分析方法在木材缺陷检测中的适用性。研究结果表明:曲率模态是一个对木梁损伤比较敏感的参数,可用于对孔洞位置、大小及数量进行定量的估计;通过降低有限元模型局部单元的弹性模量能够较好地模拟木梁损伤,有限元模态分析和试验模态分析得到的位移模态振型及曲率模态吻合均较好,验证了模态分析对木梁无损检测是一种有效的方法。To effectively detect the local defects of wood structure components, the finite element method(FEM) and experimental modal analysis(EMA) were employed to generate the first displacement mode shape of wood beams.Then the displacement mode shape was used to compute modal curvature by using the central difference method.The change of modal curvature before and after damage in wood beams was compared.Different severities,locations and the number of damage were simulated by digging a hole in the intact wood to verify the modal curvature generated by both FEM and EMA.The results show that modal curvature is a sensitive parameter to wood damage.It is feasible to quantitatively detect the location,severity and number of damage.Meanwhile,modal analysis technology was proved a good way to nondestructively evaluate the damage in wood beams.

关 键 词：有限元 木梁 曲率模态 损伤识别 试验模态分析 

分 类 号：TU317[建筑科学—结构工程] TU366.2