基于轴向模态应变能比法的三维桁架结构损伤定位方法

摘要

提出了可用于诊断三维桁架结构的损伤指标-轴向模态应变能比法.该指标仅利用结构的前两阶模态参数,无需转动自由度信息.通过四腿导管架海洋平台结构有限元模型,数值模拟不同构件的多种损伤工况对该指标进行验证,最后通过海洋平台物理模型实验对该方法进行了实验验证.验证结果表明该法可有效地诊断三维桁架结构的损伤.%An improved damage inspection method based on axial modal strain energy ratio was presented for identifying a crack in a three-dimensional truss structure.The improved method was used to predict the existence and the approximate location of a crack by using only the first two order modal parameters without any rotational DOF degree information.With the finite element model of a jacket platform,several damage cases of its different members were simulated numerically to verify the index of axial modal strain energy ratio.This method was also verified with a physical model test for a jacket platform.The final results showed that the proposed axial modal strain energy ratio method can effectively diagnose three-dimensional truss structure's damage.