摘要
摘要
星载桁架天线质量低、柔性大且工作于真空与零重力环境，一旦受到来自陨石撞击、卫星调姿或温度变化等载荷的干扰，很容易激起低频、大幅度、长时间的振动，严重影响天线乃至卫星的工作性能。因此，研究桁架天线结构的振动控制成为一个非常重要的课题。形状记忆合金是一种具有形状记忆效应和超弹性效应的新型智能材料，它的出现为结构振动控制问题提供了新的解决方案，是目前重要研究方向之一。相较于其他控制材料，形状记忆合金在结构振动控制方面具有驱动位移大、驱动力大、不受真空环境影响等优势。本文针对形状记忆合金在振动控制方面的优势，将其安装在星载桁架天线上，研究它对星载桁架天线的振动控制效果。主要工作内容如下：
1. 分析了形状记忆合金的超弹性效应与形状记忆效应的内在机理，总结了几种唯象本构模型，详细介绍了ABAQUS与ANSYS中形状记忆合金材料模型的几种实现方法；在ABAQUS与ANSYS中建立仿真模型，验证其对形状记忆合金特性的模拟效果，结果表明，ABAQUS与ANSYS均能很好的模拟形状记忆合金的超弹性效应与形状记忆效应。
2. 根据形状记忆合金被动耗能减振原理，在ABAQUS中建立了桁架天线与形状记忆合金的仿真模型，分别研究了形状记忆合金拉索与形状记忆合金阻尼器两种减振方案对桁架天线的减振效果，仿真分析结果
表明，安装了形状记忆合金拉索或形状记忆合金阻尼器的桁架天线振动控制效果明显，有效地抑制了天线的振动。
3. 利用ANSYS分析了预应变、温度变化对形状记忆合金受限回复的影响，验证了ANSYS能够实现对形状记忆合金受限回复的模拟；分析了电流强度、合金丝直径、热交换系数等参数对升温和降温速度的影响，进一步分析了温度变化对形状记忆合金回复力的影响。根据形状记忆合金受限回复时能够产生很大回复力的特性，将形状记忆合金丝嵌入桁架天线支撑臂中，在ANSYS中建立了支撑臂与形状记忆合金的复合梁模型，通过半主动控制算法控制合金丝的温度变化，实现对桁架天线的振动控制。仿真分析结果表明，形状记忆合金与支撑臂的复合梁结构，结合半主动控制算法能够显著的抑制星载桁架天线的振动。
本文研究结果表明，形状记忆合金能够对星载桁架天线的振动进行控制，实现抑振的目的。
janna关键词：形状记忆合金，星载桁架天线，振动控制，ANSYS，ABAQUS
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西安电子科技大学硕士学位论文
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ABSTRACT
ABSTRACT
Truss Antenna on Satellite are low quality, flexible and in a vacuum and zero gravity environment, once excited by loads such as meteorite impact, satellite attitude or temperature changes, it is easy to provoke low-frequency, large-scale, long-term vibration, which riously affects the performance of the antenna and even the satellite. Therefore, studying the vibration control of the truss antenna structure has become a very important issue. Shape memory alloys is a new type of smart material with shape memory effect and superelastic effect,and using shape memory alloys to control the vibration of structure is one of its important rearch directions. Compared with other control materials, shape memory alloys have the advantages of large drive displacement, large driving force and no influence from vacuum environment in structural vibration control. In this paper, the advantages of shape memory alloys in vibration control are installed on the spaceborne truss antenna to study its vibration control effect on the spaceborne truss antenna. The main work is as follows:
1. The intrinsic mechanism of superelastic effect and shape memory effect of shape memory alloys i
s analyzed, summary of veral phenomenological constitutive models, veral implementation methods of SMA material model in ABAQUS and ANSYS are introduced in detail; The simulation results of shape memory alloys were verified by using ABAQUS and ANSYS simulation models. The results show that both ABAQUS and ANSYS can simulate the superelastic effect and shape memory effect of shape memory alloys.
2. According to the principle of passive energy dissipation of shape memory alloys, a simulation model of truss antenna and shape memory alloys was established in ABAQUS. Two kinds of vibration reduction schemes, shape memory alloys cable and shape memory alloys damper, were ud to study the truss antenna. The vibration damping effect and simulation analysis show that the vibration of the truss antenna with shape memory alloys cable and shape memory alloys damper is obviously attenuated, which effectively suppress the vibration of the antenna.
3. The effect of pre-strain and temperature change on the limited recovery of shape memory alloys was analyzed by ANSYS. It was verified that ANSYS can realize the
西安电子科技大学硕士学位论文mutual
simulation of limited recovery of shape memory alloys. The parameters such as current intensity, wir
e diameter and heat exchange coefficient were analyzed. The influence of temperature change on the driving force of shape memory alloys was further analyzed by the influence of cooling process. According to the characteristics of large recovery force when the shape memory alloys is limited to recover, the shape memory alloys wire is embedded in the truss antenna support arm, and the composite beam model of the support arm and shape memory alloys is established in ANSYS, and the mi-active control algorithm is adopted. Control the temperature change of the alloys wire to achieve vibration control of the truss antenna. The simulation analysis results show that the composite beam structure of shape memory alloys and support arm can effectively suppress the vibration of the antenna.
The results of this paper show that the shape memory alloys can control the vibration of the spaceborne truss antenna and achieve the purpo of vibration suppression.
Keywords: Shape Memory Alloys, Truss Antenna on Satellite, Vibration Reduction, ANSYS, ABAQUSzdl
插图索引
插图索引
图1.1 星载桁架天线运行图 (1)
图1.2 常用材料驱动力、驱动应变和体积能量密度对比 (2)
英语语法图1.3 普通金属和SMA材料应力-应变曲线对比 (3)
图1.4 SMA形状记忆效应示意图 (4)
图1.5 SMA超弹性示意图 (4)
图1.6 SMA的电阻特性 (5)scary
图1.7 结构振动控制原理图 (6)
图1.8 反弯点SMA拉索被动减振示意 (9)
图1.9 SMA拉索的两层框架结构模型 (9)女孩的英文名
图1.10 “阿波罗”11号登月舱智能天线 (11)
图2.1 形状记忆合金相图 (14)
图2.2 形状记忆效应的降温过程 (15)
图2.3 形状记忆效应的施加变形过程 (15)
图2.4 形状记忆效应的形变恢复过程 (16)
图2.5 SMA的超弹性相变过程 (16)精致的意思
考研英语听力
图2.6 Tanaka本构模型相变图 (18)
图2.7 Auricchio本构模型中参数示意 (20)
图2.8 SMA超弹性试件模型 (22)
图2.9 SMA模型加载过程示意图 (23)
图2.10 SMA超弹性应变变化曲线 (23)
图2.11 SMA超弹性应力应变曲线 (24)
图2.12 SMA形状记忆试件模型 (24)
图2.13 SMA形状记忆过程位移云图 (25)
图2.14 变形位移历程曲线 (25)
图2.15 应力应变曲线 (26)
图3.1 星载空间桁架天线总体结构示意图 (27)
图3.2 环形可展开桁架天线结构图 (28)花生的英文
图3.3 桁架天线与支撑臂有限元模型示意图 (29)
图3.4 所有索段的预紧力分布图 (31)
图3.5 天线前五阶模态振型 (33)
图3.6 远端节点X向无阻尼自由振动 (34)
