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为研究CFRP拉索模态耦合内共振特性,建立了反映拉索面内、外1阶模态耦合作用的二自由度振动模型,该模型考虑了索的垂度、大位移等引起的几何非线性。利用该模型,采用数值方法分析了相同条件下的CFRP拉索和钢拉索在纯平面和非平面荷载作用下的内共振响应,并研究了外激励幅值、阻尼比、初始扰动等对内共振的影响。研究结果表明,当拉索的面内、外频率满足共振条件时,拉索同时发生荷载作用面内的主共振和面内、外的内共振;随着外激励幅值的增大,2种拉索面内、外最大位移增大,当外激励幅值小于一定值时,2种拉索不能发生内共振;随着阻尼比的增大,拉索发生内共振时的最大和稳态振幅呈现减小的趋势,当阻尼比分别增大到一定程度时,2种拉索不能发生内共振;随着初始扰动的增大,拉索的面内、外最大振幅和稳态振幅基本保持不变,但能量从面内传递到面外所用的时间变短;在运动过程中,CFRP索拍频明显高于钢索,其由瞬态振动进入到稳态运动的时间均早于钢索,而最大振幅和稳态振幅小于钢索。
In order to study the mode coupling internal resonance characteristics of CFRP cable, a two-degree-of-freedom vibration model was established to reflect the first-order mode coupling effect in the plane of cable. The model considered the nonlinearity caused by dip, Linear. Using this model, the internal resonance responses of CFRP cables and steel cables subjected to purely planar and non-planar loads under the same conditions were analyzed numerically. The effects of external excitation amplitude, damping ratio, initial perturbation, etc. on internal Resonance effects. The results show that when the in-plane and out-of-plane frequencies of the cable satisfy the resonance conditions, the main resonance and the in-plane and out-of-plane resonances of the cable occur simultaneously. With the increase of the external excitation amplitude, When the amplitude of external excitation is less than a certain value, the internal resonance can not occur in the two cables. With the increase of the damping ratio, the maximum and steady-state amplitudes of the internal resonance of the cable When the damping ratio increases to a certain extent, the internal resonance can not occur in the two kinds of cables. As the initial disturbance increases, the maximum amplitude and the steady amplitude in-plane and outside of the cable stay basically unchanged While the energy transfer from the surface to the out-of-plane time is shorter; during the exercise, CFRP cable beat frequency was significantly higher than the cable, the transient vibration into the steady-state motion earlier than the cable, The maximum amplitude and steady-state amplitude less than the cable.