拉索参数振动及其多场耦合下的非线性振动研究

发布时间：2018-05-21 17:16

本文选题：斜拉索 + 参数振动　；参考：《江苏大学》2017年硕士论文

【摘要】：斜拉结构作为一种柔性结构具有优异的力学性能和空间延展能力,被广泛的应用于国民的生产、生活中。例如,目前应用非常广泛的斜拉桥结构、斜拉大跨空间结构,以及拟建中的悬浮隧道结构等。斜拉结构,一般可视为由三个主要构件组成:塔(柱)、斜拉索、悬挂体(悬浮体)。其中塔(柱)一般提供竖向支撑,悬挂体(悬浮体)提供空间延展性,斜拉索将悬挂体(悬浮体)和塔柱连接起来,组成斜拉结构。本文回顾了国内外斜拉结构拉索参数振动的研究现状,分别介绍了斜拉桥拉索、悬浮隧道锚索、斜拉空间结构拉索及桅杆纤绳等拉索参数振动的研究进展。相关文献表明虽然斜拉结构的具体形式有所差异但其发生参数振动的机理均相同,均会发生参数振动危害。通过对水平拉索的静力分析,分别建立了拉索静力作用下忽略物理刚度和考虑物理刚度影响时的初始构型。通过算例对忽略物理刚度时的两种初始构型(悬链线构型、抛物线构型)进行了对比分析,讨论了抛物线构型的适用性,指出在正常工作情况下,使用抛物线构型能够满足工程精度的需要。绘制了物理刚度影响系数和垂度变化率的曲线图,分析了物理刚度对拉索垂度的影响,通过对水平拉索的动力分析,建立了水平拉索考虑物理刚度的自由振动方程,分析了物理刚度对拉索振动频率的影响,指出在正常工作情况下,物理刚度对于拉索垂度及自振频率的影响均较小。将拉索的端部激励视为理想激励,建立了水平拉索在横向激励下的强迫振动方程和轴向激励下的参数振动方程。考虑斜拉索端部的参、强耦合激励,建立了理想激励下斜拉索参、强耦合振动方程,通过数值计算分析了斜拉索参数激励和参、强耦合激励下的振动响应。指出,同一斜拉结构中,长索容易被激发主共振、短索更容易被激发主参数共振;受强迫振动的影响短索的主参数共振激发时间会提前,长索的主参数共振时间会推迟。将拉索的端部激励视为非理想激励,考虑流场的影响,建立了涡激和参数激励下斜拉索-悬浮体的耦合振动模型,分析指出,水体能够有效削弱锚索的参数振动,当瞬时参数振动现象依然不容忽视;锚索对平台的初始扰动更为敏感;增大平台阻尼能够更为有效的消弱锚索的参数振动;涡激力的存在并不会显著增大锚索的最大振幅,但会为锚索参数振动提供初始扰动,同时导致拉索发生持续的周期振动。考虑温度的影响,建立了考虑温度的斜拉索-悬挂体耦合振动模型,分析了温度影响下斜拉索的振动响应。指出,温度对于拉索振动的影响主要体现在对拉索自振频率和参数共振激励频率上,温度降低会增大拉索参数共振的激励频率,减小参数共振区域导致共振区向后偏移;温度升高会减小拉索参数共振的激励频率,增大参数共振区域导致共振区向前偏移。温度对于拉索参数振动幅值的影响较小,可以忽略。
[Abstract]:As a flexible structure, cable-stayed structure has excellent mechanical properties and space extension ability. It is widely used in production and life of Yu Guomin. For example, the cable-stayed bridge structure, the long-span cable-stayed space structure and the proposed suspension tunnel structure are widely used at present. Cable-stayed structures are generally considered to consist of three main components: towers (columns, stay cables, suspensions). The tower (column) generally provides vertical support, the suspension (suspension) provides space ductility, and the stay cable connects the suspension (suspension) and the tower column to form a cable-stayed structure. This paper reviews the research status of cable parametric vibration of cable-stayed structure at home and abroad, and introduces the research progress of cable parameter vibration of cable-stayed bridge, suspension tunnel anchor cable, cable-stayed space structure cable and mast fiber rope respectively. The related literatures show that although the concrete form of cable-stayed structure is different, the mechanism of parametric vibration is the same, and the damage of parametric vibration will occur. Based on the static analysis of horizontal cables, the initial configuration of cables with physical stiffness and physical stiffness is established respectively. Two initial configurations (catenary configuration, parabola configuration) which ignore physical stiffness are compared and analyzed, the applicability of parabola configuration is discussed, and it is pointed out that under normal working conditions, Using parabola configuration can meet the need of engineering precision. The curves of influence coefficient and sag change rate of physical stiffness are drawn, and the influence of physical stiffness on cable sag is analyzed. Through dynamic analysis of horizontal cable, the free vibration equation of horizontal cable considering physical stiffness is established. The effect of physical stiffness on cable vibration frequency is analyzed. It is pointed out that under normal working conditions, physical stiffness has little effect on cable sag and natural vibration frequency. Considering the end excitation of the cable as the ideal excitation, the forced vibration equation of horizontal cable under transverse excitation and the parametric vibration equation under axial excitation are established. Considering the parameter and strong coupling excitation at the end of stay cable, the vibration equations of cable parameter and strong coupling under ideal excitation are established, and the vibration responses of cable parameter excitation and parameter excitation under strong coupling excitation are analyzed by numerical calculation. It is pointed out that in the same cable-stayed structure, the main resonance of the long cable is easily excited, the resonance of the main parameter of the short cable is more easily excited, the excitation time of the resonance of the main parameter of the short cable affected by forced vibration will be advanced, and the resonance time of the main parameter of the long cable will be delayed. Considering the effect of flow field, the coupled vibration model of cable-suspension subjected to vortex excitation and parametric excitation is established. It is pointed out that the water body can effectively weaken the parametric vibration of anchor cable. When the transient parametric vibration phenomenon is still not to be ignored; the cable is more sensitive to the initial disturbance of the platform; increasing the damping of the platform can effectively attenuate the parametric vibration of the anchor cable; the existence of vortex-induced force does not significantly increase the maximum amplitude of the anchor cable. But it can provide initial disturbance for cable parameter vibration and cause continuous periodic vibration of cable. Considering the influence of temperature, the coupled vibration model of cable-suspension with temperature is established, and the vibration response of stay cable under the influence of temperature is analyzed. It is pointed out that the effect of temperature on cable vibration is mainly reflected in the natural vibration frequency and parametric resonance excitation frequency of cable, and the decrease of temperature will increase the excitation frequency of cable parametric resonance, and reduce the parametric resonance region leading to the backward deviation of resonance region. The temperature rise will reduce the excitation frequency of cable parametric resonance, and increase the parametric resonance region leading to the forward deviation of the resonance region. The temperature has little effect on the vibration amplitude of cable parameters and can be neglected.
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU311.3

【参考文献】