波形钢腹板PC组合箱梁的扭转振动特性

Torsional Vibration Characteristic of PC Composite Box Girder with Corrugated Steel Webs

根据波形钢腹板PC组合箱梁的特性,运用Hamilton原理推导了波形钢腹板PC组合箱梁考虑剪切变形时的扭转振动频率计算公式.以5.2 m波形钢腹板试验梁为对象进行了模态试验,并利用有限元软件ANSYS建立波形钢腹板PC组合箱梁的模型进行模态分析.通过对试验梁模态试验的扭转振动频率的实测值、理论计算值以及有限元分析数据进行对比分析,证明了理论公式推导的正确性,论证了有限元模型的适用性,并通过分析得出剪切变形对波形钢腹板PC组合箱梁的扭转振动性能有较大影响.文中还利用参数分析的方法,分析波形钢腹板厚度以及波折角对该组合箱梁的扭转振动频率的影响,结果表明:随着钢腹板厚度的增加,波形钢腹板PC组合箱梁的扭转振动频率相应增大;随着钢腹板波折角的增大,波形钢腹板PC组合箱梁的扭转振动频率有所减小.

According to the characteristics of the PC composite box girder with corrugated steel webs,a formula calculating the torsional vibration frequency of the composite box girder is proposed based onthe Hamilton theory,which considers the shear deformation of the composite box girder. Then,a 5. 2 m experimental box girder model with corrugated steel webs is taken as the objective to conduct a modal experiment,and a modal analysis is performed by adopting the finite element analysis software ANSYS to construct a finite element model of PC composite box girders with corrugated steel webs. By comparing the measured value,the theoretical value and the finite element analysis results,both the correctness of the proposed formula and the applicability of the finite element model are verified. Analytical results show that the shear deformation has a great influence on the torsional vibration performance of the composite box girder with corrugated steel webs. Finally,through the parameter analysis,the influences of the thickness and folded angle of corrugated steel webs on the torsional vibration frequency of the composite box girder are analyzed. The results show that the torsional vibration frequency of the composite box girder with corrugated steel webs increases with the thickness of corrugated steel webs,while it decreases with the increase of the folded angle of corrugated steel webs.