基于LS--DYNA与耦合方法的简支板桥车桥振动分析

Vehicle-Bridge Vibration Analysis of Simply Supported Slab Bridge Using Coupling Method with LS-DYNA

简支空心板桥是我国小跨径桥梁中广泛采用的桥型之一。这类桥梁具有重量轻、整体性好、自振频率高的特点,且在高速重载车辆的作用下易导致车桥间产生较大的动力相互作用。这一现象不仅影响车辆行驶的舒适度,而且会对桥梁结构产生不利影响,降低桥梁寿命。将当前广泛应用的车桥耦合方法与动力有限元软件LS-DYNA结合起来,建立了一种全新的车桥耦合三维仿真分析模型。车桥耦合模型中的车辆模型采用了简化的三维9自由度车辆模型,简化了车辆建模并提高了计算效率。基于一简支现浇空心板桥的现场试验,将由这种耦合方法得到的仿真分析结果与实桥测试动力响应进行对比分析。结果表明,测试结果和仿真模拟结果吻合良好,验证了这种新的车桥耦合三维仿真分析模型的正确性和有效性。

Simply supported slab bridge is one of the most widely used bridge type in short-span bridges. This kind of bridge has the characteristics of low mass, good integrity and high modal frequencies, which may lead to significant bridge-vehicle interactions when subject to fast heavy vehicles. The significant interaction would not only impact the comfort of drivers, but also harm the existing bridge structure and reduce its service life as well. Combined with the method that was widely used in the vehi- cle-bridge coupling analysis and the dynamic finite element software LS-DYNA, this paper establishes a novel 3-D vehicle-bridge coupling simulation model. In the coupling model, the vehicle model is simpli- fied as 3-D nine degree of freedoms, which reduces the process in establishing the vehicle model and in- creases the computation efficiency. Based on the field tests on a simply-supported slab bridge, the simu- lated dynamic responses by the established novel coupled vehicle-bridge model are compared with the measured ones by transducers. The comparison shows that the measured dynamic responses agrees well with the simulated ones, which indicates that proposed 3-D coupled vehicle-bridge simulation model is accurate and effective.