基于形状记忆合金的结构刚度控制研究

发布时间：2018-01-27 15:35

本文关键词： 热效应形状记忆合金刚度控制回复应力布局优化　出处：《南京航空航天大学》2014年硕士论文　论文类型：学位论文

【摘要】：本文主要针对气动加热环境结构刚度下降的问题，基于形状记忆合金的特性，提出采用形状记忆合金驱动器对其进行刚度控制。首先，通过有限元仿真揭示了气动加热环境下对弹体结构固有频率的影响，并根据形状记忆合金的特性提出了刚度控制策略。其次，讨论了适用于回复应力计算的形状记忆合金一维本构模型，设计对形状记忆合金驱动器预拉伸和性能测试的实验装置，应用Brinson一维本构模型计算不同预应变的形状记忆合金丝回复应力随温度的变化，并与实验结果相比较。第三，针对MSC.NASTRAN不能很好地建立形状记忆合金材料，结合实际工程需要，，利用PATRAN的二次开发语言将一维形状记忆合金材料系统集成到PATRAN中，通过开发的模块实现了商业有限元软件中对布置有形状记忆合金材料的驱动结构以及复合材料结构进行有限元建模分析。同时针对气动加热引起的高温效应使结构刚度降低的现象，提出了利用形状记忆合金纤维埋入结构中进行刚度控制的方法。从建立SMA纤维混杂层合板出发，研究了温度载荷下结构刚度特性与SMA的初始预应变、体积含量关系。最后，研究了基于形状记忆合金的平板结构刚度控制方法，提出了驱动器在平板上的布置形式。通过建立分析有限元模型并结合实验验证控制效果，在此基础上进一步采用遗传优化算法对驱动器布局方式进行优化，优化后的布置方案可实现利用较少的SMA驱动器提高刚度控制效果，为利用形状记忆合金实现对结构的刚度控制提供参考和借鉴。
[Abstract]:Based on the characteristics of shape memory alloy (SMA), a shape memory alloy (SMA) driver is proposed to control the stiffness of pneumatic heating environment. Firstly, the influence of aerodynamic heating on the natural frequency of projectile structure is revealed by finite element simulation, and the stiffness control strategy is proposed according to the characteristics of shape memory alloy. Secondly, the one-dimensional constitutive model of shape memory alloy (SMA), which is suitable for the calculation of recovery stress, is discussed, and an experimental device for testing the pretension and properties of the SMA driver is designed. The recovery stress of shape memory alloy wire with different prestrain was calculated by Brinson one-dimensional constitutive model and compared with the experimental results. Third, MSC.NASTRAN can not build shape memory alloy materials well, combined with the actual engineering needs. One-dimensional shape memory alloy material system is integrated into PATRAN by using the secondary development language of PATRAN. The commercial finite element software has been developed to model and analyze the driving structure and composite structure of shape memory alloy material. At the same time, the high temperature effect caused by pneumatic heating is used to make the junction. The phenomenon of structural stiffness decreasing. In this paper, a method of stiffness control with shape memory alloy fiber embedded in the structure is proposed. Based on the establishment of SMA fiber hybrid laminated plate, the stiffness characteristics of the structure under temperature load and the initial prestrain of SMA are studied. Volume content relationship. Finally, the stiffness control method of flat plate structure based on shape memory alloy is studied, and the layout of the actuator on the plate is proposed. The finite element model is established and the control effect is verified by experiments. On the basis of this, genetic optimization algorithm is used to optimize the layout of the driver. The optimized layout can use less SMA driver to improve the stiffness control effect. It provides a reference for the stiffness control of the structure by using shape memory alloy.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TG139.6

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