摘要
利用结构力学中的虚功原理,推导简支梁桥在损伤前后曲率差公式,得出简支梁曲率差模态指标与损伤位置有关结论.研究单一损伤位置和多处损伤位置及不同损伤程度对结构损伤识别的影响,分析损伤前后结构固有频率的变化情况.结果表明:结构无论发生单一或多处损伤时,曲率差模态曲线会在损伤单元处发生尖峰突起;低阶模态就可以准确地确定损伤位置,为防止损伤发生在某阶振型的0节点处,需要综合高阶模态互相对照分析损伤情况;用结构损伤前后各阶自振频率变化,可以整体对结构是否有损伤进行判别.
The virtual work principle in structural mechanics was used to derive the formula of curvature difference for a damaged bridge with simply supported beam before and after its damage,and a conclusion was obtained that the index of modal curvature difference was related to damage location.The influence of single damage location,multiple damage location,and degree of injury on the structural damage identification was investigated.The variation of intrinsic frequency of the structure before and after its damage was analyzed,also.Numerical simulation result showed that no matter whether single damage location or multiple damage location happens to the structure,a protrusive peak would occur on the modal curve of curvature difference at the position of damaged element.Thus,the damage location could precisely be determined with the help of the low-order modality.In order to prevent the damage from occurring at zero-node of some ordered vibration mode,it needed to compare comprehensively the higher order modes with each other and,then,analyze the damage situation.Whether the damage would occur to the structure could globally be identified according to the variation of self-oscillatory frequency of all orders before and after structural damage.
出处
《兰州理工大学学报》
CAS
北大核心
2010年第5期122-127,共6页
Journal of Lanzhou University of Technology
基金
甘肃省科技支撑项目(0708GKCA002)
甘肃省自然科学基金暨中青年科技基金(3ZS062-B25-031)
关键词
桥梁健康监测
损伤识别
模态曲率差
固有频率
模态分析
bridge health monitoring
damage identification
difference of modal curvature
intrinsic frequency
modal analysis
