在恒载作用下破坏时的再分配的方法论[外文翻译].docx

在恒载作用下破坏时的再分配的方法论

Harry W. Shenton III, A.M.ASCE1; and Xiaofeng Hu2

摘要: 这是一种研究目前的民用建筑在恒载作用下如何识别结构大规模破坏的新方法。由于静荷载唯一的被输入到识别程序里，所以这种方法用于静应变测量。一种确定固定梁的解析模型出现在由截面抗弯刚度减少而产生破坏的地方。这种破坏状态由位置、长度，和迅速降低的强度来确定的。 一个关于横梁反应的前沿分析首先被用来阐明不同的破坏方案如何导致静荷载再重心分布的。 那相反的问题是放宽约束条件并利用一几何算法来解决。 建议方法正确地识别由于大范围强度破坏而导致梁的破坏。 通常这个识别程序在强度破坏增加时有一个较大的可信度。结果表明当它接近未破坏梁的弯曲点时破坏很难识别，这个弯曲点就是在静荷载应力为零的地方。 识别破坏能力不同观点的影响效果正在进行问卷中调查。
DOl: 10.1061/(ASCE)0733-9445(2006) 132:8(1254)

关键词：恒载  梁  运算法则  监测  最优化  应变  破坏

Damage Identification Based on Dead
Load Redistribution: Methodology
Harry W. Shenton III, A.M.ASCE1; and Xiaofeng Hu2
Abstract: A new method for damage identification in large, massive civil structures is presented, which is based on the idea that dead load is redistributed when damage occurs in the structure. The method uses static strain measurements due to dead load only as input to  the identification procedure. An analytical model of a fixed-fixed beam is developed in which the damage is represented by a section of reduced flexural rigidity. The damage state is determined by the location, length, and severity of the stiffness reduction. A forward analysis of the beam response is first presented to illustrate how the dead load is redistributed for different damage scenarios. The inverse problem is defined by a constrained optimization problem and is solved using a genetic algorithm. The proposed method correctly identified damage in the beam for a wide range of locations and damage severities. The identification procedure, in general, has a greater degree of success with increasing damage severity. Results show that damage is difficult to identify when it is close to the inflection point of theundamaged beam, where the dead load strain is zero. The effect of measurement noise on the ability to identify damage is investigated in the companion paper.
DOl: 10.1061/(ASCE)0733-9445(2006) 132:8(1254)
CE Database subject headings: Dead loads; Beams; Algorithms; Monitoring; Optimization; Strain; Damage.