公路弯梁桥模态测试的测点布置

Measure Point Layout of Modal Test of Highway Curved Beam Bridge

为得到测试公路弯梁桥模态振型的测点优化布置方案,采用有效独立法运算测点布置位置,并引入模态保证准则检验测点的准确性。以某实际三跨连续弯梁桥为工程背景,通过MATLAB编制有效独立法寻找相应测点位置的程序,分别计算了前10阶模态的传感器布置测点;计算各阶模态测点的模态向量空间夹角(PiMAC值);并选取其中4阶模态进行实桥验证。结果显示:多数PiMAC值满足模态保证准则,并且实桥测试结果与有限元模态相似度很高;结果表明:测点布置方案可以运用到三跨连续弯梁桥的模态测试中,有效独立法能有效为公路弯梁桥在环境激励下开展模态测试提供测点布置参考。

In order to obtain the optimal layout of the measuring points for testing the modal shape of the highway curved beam bridge,the effective independent method was used to calculate the layout position of measuring points,and the modal assurance criterion was introduced to check the accuracy of the measuring points. Taking an actual three-span continuous curved beam bridge as an engineering background,the program of finding the location of corresponding measuring points by the effective independent method was compiled by MATLAB,and the sensor arrangement measuring points of the first 10 modes were calculated respectively. The angle of the modal vector space( PiMAC value) of each modal measuring point was calculated,and four modes among them were selected for real bridge verification. The results show that most of the PiMAC values meet the modal assurance criterion,and the results of real bridge test are very similar to those of the finite element modal,which indicates that the proposed scheme of measuring point arrangement can be applied to the modal test of threespan continuous curved beam bridge,and the effective independent method can effectively provide a reference for the measuring point layout of modal test of highway curved beam bridge under environmental excitation.