基于曲率模态振型的刚架结构损伤检测

DAMAGE DETECTION FOR FRAME STRUCTURE USING CURVATURE MODE SHAPES

结构损伤前后动力特性的变化来快速、直接、方便地判定损伤的存在、程度及位置.本文采用曲率模态对刚架结构的损伤检测进行了研究.首先用有限元法计算出结构的位移模态振型,然后用差分法计算出曲率模态振型.数值模拟结果表明:曲率模态振型对结构的损伤敏感,可同时确定结构损伤的存在、程度和位置,并且可以用于结构多位置损伤的检测.实验结果证实了数值模拟结论.

The structure damage detection method uses the changes in dynamic parameters between the intact and damage states to evaluate and localize damage directly, fast and inexpensively. This paper adopted the curvature mode shape to investigate the damage in frame structure. The Finite element analysis was used to obtain the displacement. By using the central difference approximation, the curvature mode shapes were then calculated from the displacement mode shapes. Numerical simulation results show that the changes of curvature mode shapes are sensitive to the damage in the frame structure. Thus, the curvature mode shapes can indicate the presence of damage and its severity, and locate damage at the same time. Curvature mode shape is also suitable for detection of multiple damages. The experimental result further verifies its sensitivity to structural damage.