桥梁涡激共振试验节段模型质量系统模拟与振幅修正方法

节段模型风洞试验是研究涡激共振风速锁定范围和最大振动幅值的一种重要手段。基于一个具有自激特性的经验线性涡激力模型,从涡激共振微分方程出发,推导了涡激共振试验节段模型质量系统模拟公式,并建立了相应的模型与实桥之间涡激共振幅值的换算关系,给出了涡激共振幅值的振型修正系数和阻尼修正系数公式。由此,通过合理的质量系统模拟和响应幅值换算,可在二维的涡激共振节段模型试验中考虑实桥的结构和振动的三维特性的影响。

MASS SIMULATION AND AMPLITUDE CONVERSION OF BRIDGE SECTIONAL MODEL TEST FOR VORTEX-EXCITED RESONANCE

Wind tunnel test of sectional model is an important means for determining lock-in region of wind speed and maximal amplitude of vortex-excited resonance. The simulation formulae for the mass system of sectional model are derived based on the differential equation of vortex-excited resonance and an experimental linear model of vortex-excited force with self-excited behavior. The conversion relationships between the resonant amplitudes of the sectional model and the prototype bridge are also established, and the correction coefficients of mode shape and damping are presented as well. The effects of the three-dimensional structural and vibrational behavior of prototype bridge can thus be considered in the two-dimensional sectional model test of vortex-excited resonance via the proper mass simulation and amplitude conversion by means of the derived formulae.