基于有限测点信息的结构损伤识别柔度法

利用有限测点获得结构的模态参数，提出了基于有限测点的结构损伤识别的柔度法。该方法是通过仅考虑结构柔度的灵敏度分析，以结构各自由度的损伤信息为条件，选择对结构柔度变化敏感的自由度为测点，并利用有限测点的信息提出了结构完备模态振型的重建技术。在此基础上，对柔度矩阵做关于结构物理参数变化量的一阶泰勒展开，来确定结构单元的损伤因子对结构进行损伤识别。从而实现利用结构有限测点的模态信息来识别结构的损伤，解决了测试结构的模态振型的不完整给结构的损伤诊断带来的困难。通过数值算例说明了该方法的有效性。

Structural damage detection using flexibility from limited sensor information

In this study, an identification technique based on the measured flexibility matrices is developed to assess damage in continuum structure, where the information about incomplete modal data can be directly utilized. The incomplete mode shapes for the damaged structure can be expanded into complete mode shapes by using the actual measured modal readings and assuming the unknown modal data for the remaining dimension. The collected information of the choice sensor placement is optimized according to the ability of collecting structural damage information for each degree of freedom of the structure. Only limited number of structural degree of freedom including plentiful damage information is instrumented. The method of optimizing sensor placement is that sensitivity analysis for modal flexibility is based on the changes in the stiffness only. A computational technique based measure flexibility matrices change is developed for the inverse prediction of structural damage, where both the location and the extent of structural damage can be correctly determined using only a limited amount of measurements of incomplete modal data. At last, numerical examples are utilized to demonstrate the effectiveness of the proposed approach.