论文标题:斜拉桥拉索等用NiTi形状记忆合金阻尼器研究
Research on NiTi SMA Damper Used in Cables of Cable-Stayed Bridges and Other Kinds of Cables
论文作者
论文导师 韩玉林,论文学位 硕士,论文专业 工程力学
论文单位 东南大学,点击次数 82,论文页数 52页File Size810K
2005-03-10论文网 http://www.lw23.com/lunwen_930179767/
Shape memory alloy;smart material;damper;cable;cable-stayed bridges;structural control;dynamical property;restoring force model;history analysis
结构耗能减振技术是一种结构控制技术,它是通过在结构的适当位置安装耗能减振装置,利用这些装置的耗能来减小结构在强震和大风作用下的振动响应。形状记忆合金(Shape Memory Alloy,简称SMA)具有形状记忆效应、超弹性效应和高阻尼特性,利用超弹性效应制成的形状记忆合金超弹性阻尼器就是一种性能优良的耗能减振装置,可以有效的控制结构的动力响应。 本文在综述了国内外耗能减振技术的研究成果及工程应用状况后,设计了一种新型形状记忆合金超弹性阻尼器,然后针对这种新型形状记忆合金超弹性阻尼器进行了理论和试验研究,进行了装有该种阻尼器的拉索结构的振动有限元分析,最后设计了斜拉桥拉索试验模型,做了在不同情况下安装阻尼器的拉索控制试验,本文研究的主要内容和成果如下: 1、基于SMA的超弹性特点,研制了一种新型SMA阻尼器,这种阻尼器能够控制索杆结构垂直于索杆轴线任何方向的振动,能够将这些方向的振动转化为拉压作用,因此该阻尼器特别适用于索杆结构。 2、对该种新型阻尼器进行了力学分析,推导了拉压作用下力与位移公式;并计算了各种工况下的耗能系数、最大阻尼力及最大位移。 3、对该种新型阻尼器进行了动态力学性能试验,试验结果表明,该种阻尼器具有较好的耗能能力,其滞回曲线与理论分析较一致。验证了理论分析方法的正确性,该种方法还可以用来分析其他种类的SMA阻尼器的阻尼能力。 4、用有限元软件进行了斜拉桥拉索振动控制时程分析,比较了在不同位置装有阻尼器和未安装阻尼器时拉索在不同荷载作用下的振动衰减过程,数值模拟证明,在有控下比无控下衰减快,且振动幅值减小。 5、设计了拉索振动控制试验用来模拟实际斜拉桥拉索的振动控制,试验结果与数值模拟分析吻合良好。
Structural vibration energy dissipation is a kind of structural control technology, which employs energy-dissipation devices installed in proper locations of the structure to dissipate part of structural vibration energy under earthquake and wind so as to reduce the structural vibration response. Shape memory alloy (SMA) is an ideal material to dissipate vibration energy because of its properties of shape memory effect (SME), super elasticity effect and damping effect. So the shape memory alloy damper, which is based on these properties, is a good kind of energy-dissipation device. It can reduce the seismic and wind-vibration response of the engineering structures effectively. So the studies on the shape memory alloy damper are valuable in theory and practice. The current situations of researches and applications of shape memory alloy damper are briefly reviewed in this thesis firstly. A new type of damper device based on shape memory alloy (SMA) wires is developed for structural control implementation. Then the theoretic and experimental study of this new type of damper technology for structural vibration energy-dissipation is performed to verify the vibration energy dissipation ability of the new type of SMA damper. Finite element method is adopted to analyze the vibration of cables installed by SMA damper. An experimental model of cable-stayed bridges is designed to do cable structure control experiments in all kinds of situation. Finally, The main contents and results are as follows. 1. Based on the properties of the SMA, a new type of damper device based on shape memory alloy (SMA) wires is developed for structural control implementation. This kind of damper can control the vibration of structures of cables and poles in all directions which is vertical about the axis of cables or poles. It can transform of all directions into tension force and compression force. So it can especially be used in cable and pole structures. 2. The theoretic study on such damper is performed, including the research on fundamental damping principle of the damper and mechanics damping analysis of such developed reduced-scale damper. The various affecting factors to the working performance of SMA damper are discussed. The formula of the output damping force and displacement is gotten when the damper is tensed or compressed. 3. The dynamical experiment of such reduced-scale damper is performed to verify the damping analysis results and the vibration energy dissipation ability of the new type of SMA damper. It is found that the experimental results are in good agreement with the theoretic values. 4. From the experimental restoring force curve, the damping coefficient and stiffness of damper are calculated. Based on these parameters of the damper, finite element method is adopted to analyze the vibration of cables controlled and uncontrolled by SMA dampers. The numerical results illustrate that displacement of the frame model is reduced greatly and its vibration decay rate is increased effectively after the developed SMA dampers are fixed in it. 5. An experimental model of cable-stayed bridges is designed to do cable structure control experiments in all kinds of situation. It is found that the experimental results are in good agreement with the theoretic values.
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