波纹钢腹板组合梁桥动力特性及车致振动响应研究

Composite beam bridge with corrugated steel webs has been paid extensive attention at home and abroad due to the advantages of making more effective pre-stressed force on the top and bottom of the beam, avoiding the inclined crack inside web, and decreasing the construction cost. Up to now, the dynamic characteristics and vibration response of coupling vehicle-bridge system with the corrugated steel web composite beam bridge have beginning been studied only. The project will research the dynamic characteristics and study the effects of diversity of factors on dynamic properties through using ANSYS to establish dynamic finite element model of corrugated steel web composite beam bridge. Establishing the equations of motion for composite beam bridge with corrugated steel web and the vehicle respectively, considering the roughness of bridge deck, an iteration solution method is presented to analyze the coupling vibration response of vehicle-bridge system based on the same displacement and coupling force at the interface. The equation of motion is solved by numerical integration using numerical integral method mode superposition technology. During analyzing the vibration response of composite beam bridge with corrugated steel web, the dynamic response of transverse, vertical and local key position will be researched respectively. Compared with the dynamic scale model test, finite element method will be confirmed to an effective approach to analyze the dynamic characteristics of composite beam bridge with corrugated steel web. The correctness of numerical analysis of vehicle-bridge coupling vibration will be validated through comparing the testing response of model test with theoretical value numerical analysis. The Research results put forward academic foundation in improving dynamic characteristics of composite beam bridge with corrugated steel web, on the other hand, optional impact coefficients will be put forward in designing composite beam bridge with corrugated steel web. The results will provided the practical significance to make the composite beam bridge with corrugated steel web used in our country widely.

波纹钢腹板组合梁桥因能有效的避免腹板斜向开裂、增强顶底板预应力效果、减少自重，在国内外桥梁界受到广泛关注。目前，波纹钢腹板组合梁桥的动力特性及车桥耦合振动响应研究尚处于起步状态。本课题拟采用ANSYS建立波纹钢腹板组合梁桥的动力有限元模型，分析组合梁桥动力特性，研究各参数对动力特性的影响；以车轮与桥面接触始终保持不脱离为条件，考虑桥面不平顺影响，建立包含三维整车模型的波纹钢腹板组合梁桥车桥耦合振动响应分析模型，并开发求解算法；重点研究波纹钢腹板组合梁桥的横、竖向及局部关键位置的振动响应。开发波纹钢腹板组合梁桥的动力缩尺模型试验测试系统，通过对比实验测试与数值分析的车桥耦合振动响应结果，效验数值分析车桥耦合振动响应的正确性。课题研究为改善波纹钢腹板组合梁桥动力特性奠定基础，对波纹钢腹板组合梁桥设计的冲击系数取值具有指导意义；对波纹钢腹板组合梁桥在我国广泛推广具有现实意义。

本课题以朝阳大桥非通航孔为工程背景，研究波形钢腹板组合梁桥动力特性及移动车辆荷载作用下的动力响应。采用ANSYS建立波形钢腹板组合梁桥动力模型，研究了桥梁结构参数对单箱多室波形钢腹板组合梁桥的动力特性及偏载系数的影响，并将波形钢腹板换成混凝土腹板，对比分析两种梁桥动力特性；推导了波形钢腹板组合梁桥动力缩尺模型相似关系，采用10:1的缩尺比，制作了室内缩尺模型，测试其动力特性并与数值结果对比；基于三维九自由度整车模型，考虑桥面不平顺激励的影响，建立单车和多车激励作用下波形钢腹板组合梁桥车桥耦合振动模型，研究单车和多车荷载对波形钢腹板组合梁桥竖向、横向及纵向动力响应的影响，分析影响该种桥型汽车荷载冲击系数的因素，提出波形钢腹板组合梁桥建议冲击系数；研究了波形钢腹板组合梁多塔斜拉桥动力特性，分析了LRB铅芯橡胶支座对多塔波形钢腹板组合梁桥隔震效果的影响及多点地震激励作用下，各种因素对波形钢腹板组合梁多塔斜拉桥振动响应的影响。研究结果表明：采用板-壳单元能有效地简化波形钢腹板组合梁桥有限元模型，改变波形钢腹板组合梁桥横隔板位置及数量能有效调整其动力特性；车速小于100km/h，波形钢腹板组合梁桥冲击系数略小于混凝土梁桥，设计时可以参考混凝土梁桥；铅芯橡胶支座能有效降低多塔斜拉桥地震响应，多点地震激励作用下多塔斜拉桥地震响应需考虑行波效应。