大型船闸人字闸门工作模态试验分析

以葛洲坝3#船闸为例,介绍了大型船闸人字闸门工作模态试验分析。经比较分析工作模态测量(简称OMA)技术特点,选择随机子空间BR识别方法,由人字门实际的载荷、边界约束及有限元模态分析成果确定合理的试验方案。试验结果表明:扭翘变形是人字门运行的基本振型,泥沙淤积等特殊载荷导致人字门在启闭过程中产生非正常的扭翘变形并使部分背拉杆为零杆,由此引起的剪切应变是引发疲劳裂纹的主要原因。

Operation Modal Analysis on Miter Gates of Large Lock

Taking the miter gate of a large lock as an example,this article introduces the operation modal analysis(OMA). After a comparative study of the technical feature of OMA, the stochastic subspace based BR identification mehod was adopted. A testing plan was formulated according to the loads exerted on the gate,boundry conditions and the modal analysis results using finite element method. Testing results show that torsional deformation is basic vibration pattern of the gate, specific loads such as bedload in the working process of the gate leads to its unusual deformation and zero stress in part of the back tie rods, and the shear strain caused by the torsional deformation forms the chief cause of fatigue cracks on the gate.