公路梁桥车桥耦合振动模型试验设计及校验

Design and validation of scale-model test system for highway beam bridge subjected to moving vehicle

根据公路桥梁车桥耦合振动特性及结构动力模型试验的相似理论,基于π定理,采用量纲矩阵分析方法,推导了车桥耦合振动模型试验相似律.几何相似比尺取10,计算了车桥耦合振动缩尺模型试验系统的相似常数;以30 m简支梁桥和330 kN载重汽车为原型,设计制作了包含有机玻璃模型桥、试验小车及附属部分的车桥耦合振动模型试验系统.通过试验测试与理论分析对比,校验了模型桥、试验小车动力特性;以单车荷载按正常行车道位置行驶在光滑桥面为例,研究了模型桥的静态和动态响应,并将模型桥测试结果与Matlab数值模拟结果对比,校验了车桥耦合振动相似理论.研究结果表明:提出的车桥耦合振动缩尺模型试验相似律关系正确,设计制作的车桥耦合振动模型试验系统可行,模型桥基频误差为0.01%,模型试验车基频理论值与实测值相差3%,试验测试结果可靠.

According to the similarity theories of structure dynamic model test and vibration particularity of highway bridge-vehicle coupling, the similarity laws of bridge-vehicle interaction system were deduced based on π theorem with dimension matrix analysis. For the simple beam bridge with span of 30 m and vehicle loading of 330 kN, the similarity constants of the scale-model system for highway bridge-vehicle interaction were calculated with geometry scale factor of 10. The bridge-vehicle interaction system of perspex model bridge, testing pony truck and appendages was established. The dynamic particularities of model bridge and testing pony truck were analyzed through testing and numerical analysis. The static and dynamic responses of model bridge were studied based on a moving vehicle running on the smooth deck along normal lane. The comparing of model bridge testing results with numerical results of practical bridge by MATLAB was used to verify the similitude laws of bridge-vehicle interaction model. The results show that the error of model bridge primary frequency is 0.01% , and the testing pony truck is 3%. The results illuminate the feasibility of model test equipment and the validity of test results.