矩形薄板通透开裂缝对固有频率和模态的影响分析  

Analysis on natural frequency and mode of clamped rectangular thin plate with all-through crack

作　　者：龚健[1] 卢奂采[1,2] 陈振安[1] 庄一舟[3] 金江明[1] 

机构地区：[1]浙江工业大学机械工程学院,浙江杭州310014 [2]浙江省信号处理重点实验室,浙江杭州310014 [3]福州大学土木工程学院,福建福州350108

出　　处：《机电工程》2015年第8期1061-1065,共5页Journal of Mechanical & Electrical Engineering

基　　金：国家自然科学基金资助项目(51205354;51275469);浙江省国际合作重大专项资助项目(2013C14014)

摘　　要：针对四边固支矩形板薄受到通透开裂影响,引起模态中固有频率和模态振型变化的问题,对两种开裂位置中不同开裂长度进行了研究。首先,应用ANSYS软件建立有限元模型;然后,对开裂裂缝平行于薄板短边且位于板中心(对称开裂)和不位于板中心(不对称开裂)的各25种裂缝长度进行了仿真计算,获得了薄板的固有频率和模态振型。分析结果表明,裂缝的长度和位置影响矩形薄板的固有频率和振型;开裂的缝长和开裂中心位于节线上或者附近是产生模态交叉的两个重要因素,可为板结构开裂的检测提供依据。Aiming at the problem of the changes of natural frequencies and mode shapes of a clamped rectangular thin steel plate by an all- through crack, the plates with different lengths of cracks and two center of cracks were simulated. First of all, ANSYS software was used to build finite element models. Then it＇s calculated for 25 different lengths of cracks for both cases where cracks are paralleling to the short ed- ges and at the center of thin plate as well as off the center of plate, and natural frequencies and mode shapes were obtained. The results indi- cate that the length and position of all-through crack change the natural frequencies and mode shapes of the plates, and the length exceeding critical value and the center of crack around nodal line are two major factors to the mode cross-over phenomena, which can provide the effective basis for the detection of plate-like with an all-through.

关 键 词：矩形薄板 通透开裂 固有频率 模态振型 模态交叉 

分 类 号：TH132.1[机械工程—机械制造及自动化]