摘要
在严格的相似准则下,桥梁节段模型风洞试验中存在质量、刚度、阻尼等参数难以精确匹配的难题。该研究提出一种基于Strouhal(St)数与Scruton(Scr)数综合控制的不完全相似模拟方法,以实现涡激振动振幅的等效性。基于理论推导建立了无量纲振幅表达式,揭示了St数与Scr数的乘积是控制振幅一致性的关键参数,并由此提出通过调节系统阻尼和固有频率(而非单一参数)的等效原则。设计两组气动外形相同,但质量、刚度、阻尼差异显著的节段模型(缩尺比1∶50),开展风洞试验验证理论模型,结合Newmark-β法反算涡激力参数(Y_(1)、ε)及振幅。结果表明,在St·Scr保持恒定的条件下,大幅改变模型质量、刚度以及阻尼比参数值的情况下,稳态振幅与标准参数下的试验值误差均小于5%,且动态响应时程趋于稳定后幅值一致。进一步分析表明,质量较小的系统更快达到稳态,但最终振幅与质量较大系统无显著差异。该研究结果弱化了传统涡激振动试验对系统参数要求,提高涡激振动试验装置的适用性。
Under the strict similarity criterion,it is difficult to accurately match the mass,stiffness,damping and other parameters in the wind tunnel tests of bridge segment models.In this paper,an incomplete similarity simulation method based on the integrated control of Strouhal(St)number and Scruton(Scr)number was proposed to realize the equivalence of vortex-excited vibration amplitudes.A dimensionless amplitude expression was established based on theoretical derivation,revealing that the product of St number and Scr number was the key parameter for controlling the amplitude consistency,and thus proposing the equivalence principle by adjusting the system damping and natural frequency(instead of a single parameter).Two sets of segment models with the same aerodynamic shape but significant differences in mass,stiffness and damping(scaling ratio of 1∶50)were designed,and wind tunnel tests were carried out to verify the theoretical model,which were combined with the inverse calculation of the vortex excitation parameters(Y_(1),ε)and amplitude by the Newmark-βmethod.The results show that under the condition of constant St·Scr,the error between the steady state amplitude and the experimental values under the standard parameters is less than 5%when the model mass,stiffness,and damping ratio parameters are changed significantly,and the amplitudes are consistent after the dynamic response time course is stabilized.Further analysis shows that the system with less mass reaches steady state faster,but the final amplitude is not significantly different from that of the system with more mass.The results of this paper weaken the requirements of the traditional eddy oscillation test on the system parameters and improve the applicability of the vortex-induced vibration test device.
作者
汪国隆
张志田
李春光
WANG Guolong;ZHANG Zhitian;LI Chunguang(School of Civil Engineering and Architectural,Hainan University,Haikou 570228,China;School of Civil Engineering,Changsha University of Science&Technology,Changsha 410114,China)
出处
《振动与冲击》
北大核心
2025年第24期117-127,共11页
Journal of Vibration and Shock
基金
国家自然科学基金地区科学基金项目(52268073)
海南省高层次人才项目(525RC708)。
