CFRP斜拉索模态耦合内共振特性

发布时间：2018-01-16 13:41

本文关键词：CFRP斜拉索模态耦合内共振特性　出处：《中国公路学报》2017年07期 　论文类型：期刊论文

【摘要】：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。
[Abstract]:In order to study the internal resonance characteristics of CFRP cable mode coupling, a two-degree-of-freedom vibration model reflecting the in-plane and outer first-order modal coupling action of the cable is established, which takes into account the sag of the cable. By using this model, the internal resonance responses of CFRP cables and steel cables under pure and non-plane loads under the same conditions are analyzed numerically. The effects of external excitation amplitude, damping ratio and initial disturbance on the internal resonance are studied. The results show that the external frequency satisfies the resonance condition when the cable is in the plane. At the same time, the main resonance in the plane and the internal resonance in the plane and out of the plane occur at the same time. With the increase of the amplitude of external excitation, the maximum displacement of two kinds of cables increases. When the amplitude of external excitation is less than a certain value, the internal resonance of the two kinds of cables can not occur. With the increase of damping ratio, the maximum and steady-state amplitudes of the cables show a decreasing tendency when the internal resonance occurs, and when the damping ratio increases to a certain extent, two kinds of cables can not have internal resonance. With the increase of initial disturbance, the maximum amplitude and steady-state amplitude of cable remain basically unchanged, but the time of energy transfer from in-plane to off-plane becomes shorter. The beat frequency of CFRP cable is obviously higher than that of steel cable in the course of motion, and the time from transient vibration to steady state motion is earlier than that of steel cable, while the maximum amplitude and steady amplitude are smaller than that of steel cable.
【作者单位】：长安大学公路学院;诸暨市交通勘察设计室;
【基金】：国家自然科学基金项目(50908016)
【分类号】：U441.3
【正文快照】： 0引言在多自由度的空间动力系统中,当拉索的面内1阶模态和面外1阶模态接近或相等时,拉索可能发生强烈的“自耦合”内共振现象,它的实质是拉索面内(外)运动对面外(内)运动具有激励作用。斜拉索的动力特性介于标准弦与大垂度索之间,更倾向于标准弦的非线性特性,对斜拉索的研究,

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