基于模态应变能的海洋平台损伤定位试验研究

针对海洋平台等大型复杂土木工程结构，研究了基于振动响应测试的结构损伤诊断方法。采用特征系统实现算法，仅利用输出响应进行模态参数识别，基于模态应变能的变化来进行损伤定位。为了验证该方法的有效性，制造了钢质导管架式海洋平台模型，进行了振动台试验。模型预先在某些典型构件处设置了法兰连接件用来模拟损伤，针对斜撑构件测试了多种单损伤和两损伤工况。针对各种损伤工况进行了模态识别和损伤检测，试验结果表明，基于输出响应的模态应变能法进行斜撑损伤定位是可行的。

Study on Damage Localization of Offshore Platform Based on Modal Strain Energy

Natural Excitation Technique is applied to obtain the impulse responses from output signals. Then eigensystem realization algorithm is utilized to extract the modal parameters. Finally, modal strain energy is adopted to localize the damage.For investigating the feasibility and the efficacy, a steel offshore platform model is manufactured and a series of shaking table tests are conducted in the laboratory. Several damage cases including single damage and double damages of diagonal braces are considered. Results of damage localization demonstrate that the output-based modal strain energy method can localize the damage.