基于小波包能量曲率差的古木结构损伤识别  

Damage detection of an ancient wood structure based on wavelet packet energy curvature difference

作　　者：王鑫[1] 胡卫兵[1] 孟昭博[2] 

机构地区：[1]西安建筑科技大学土木工程学院,西安710055 [2]聊城大学建筑工程学院,山东聊城252000

出　　处：《振动与冲击》2014年第7期153-159,186,共8页Journal of Vibration and Shock

基　　金：国家自然科学基金面上项目(51378245);国家基金主任基金项目(51248003);陕西省科学技术研究发展计划项目(2013K13-02-08)

摘　　要：以西安钟楼为工程依托,对随机激励作用下古木结构的损伤进行有限元模拟,把古木结构梁上各节点的加速度响应信号进行小波包分解,通过小波包能量曲率差对古木结构进行损伤定位。在无噪声干扰时,该指标对于古木结构的损伤定位比较敏感,可准确判定古木结构的损伤位置,该指标随损伤程度的加大而增大。该指标在高斯白噪声干扰下,当信噪比SNR大于或等于40 db时,能对古木结构的损伤进行准确定位,该指标具有一定的抗噪声干扰能力。随后得出了损伤指标和损伤程度之间的函数关系式,用其进行损伤程度的判断并验算其适用性,为研究环境激励下西安钟楼的损伤预警提供了理论依据。Ancient wood structure damage was simulated with the finite element method under the action of random excitations with a background of Xi＇an bell tower,the node acceleration response signals on beams of the ancient wood structure were decomposed with wavelet packet.The wavelet packet energy curvature difference index for the ancient wood structure was proposed to determine the damage location.The results showed that the index is sensitive to the ancient wood structure＇s damage and it can be used to accurately determine the damage location with no noise interfence;when SNR is bigger or equal to 40db,the index can be used to determine the damage location,it has a certain anti-noise ability.The function relation between the damage index and the damage level was obtained to determine the damage level,and its applicability was verified.The study results provided a theoretical basis for damage warning of Xi＇an bell tower under environment excitation.

关 键 词：古木结构 有限元 损伤识别 小波包能量曲率差 

分 类 号：TU366.2[建筑科学—结构工程]