波形钢腹板组合箱梁自振特性与试验研究

为了精确计算波形钢腹板组合箱梁的振动频率,根据能量变分原理,推导了振动频率公式,得到了考虑剪切变形及剪力滞效应的各阶自振频率的解析解。对一试验波形钢腹板组合箱梁进行了动力测试,得到了实际自振频率,并与简单梁理论、本文理论公式与三维有限元模型的计算频率进行对比。结果表明:剪力滞效应及剪切变形对波形钢腹板组合箱梁的振动频率影响较大,考虑剪力滞及剪切变形影响后的波形钢腹板组合箱梁的振动频率有所降低,且降低程度随着计算频率阶次的增加而迅速增加,因而在波形钢腹板组合箱梁振动频率的计算中须计其影响。

Free vibration characteristics and experiment study of composite box girder with corrugated steel webs

In order to accurately calculate the vibration frequency of composite box girder with corrugated steel webs,the formula about the natural frequencies was deduced based on energy variational principle,and the analytical solution was obtained according to the effects of shear lag and shear deformation.The natural frequencies of a model were tested,and were compared with the results of simply beam theory,the theoretical formula and 3D finite element model.Comparison result shows that the effects of shear lag and shear deformation to vibration frequency are obvious,the frequencies of composite box girder with corrugated steel webs will decrease when the effects are taken into consideration,and the effects increase sharply with the increase of frequency order,so the effects can not be neglected in the frequency calculation.1 tab,5 figs,10 refs.