救助直升机绞车支架拓扑优化设计与分析

发布时间：2019-06-12 01:55

【摘要】：直升机已成为现代陆、海上人命和财产救助的一种重要装备。救助绞车系统是救助直升机上的关键装备之一,受力复杂,其结构设计影响救助过程中救生员和绞车手操作便利性、安全性和可靠性。本文基于人机工程学、拓扑优化、模态分析、疲劳分析理论,利用ANSYS Workbenc h有限元分析软件,进行了绞车支架的结构优化设计和分析,以提高其操作便利性、动态和疲劳特性。主要内容包括：(1)在分析直升机救助过程中工况和受力特点的基础上,建立绞车及支架受力分析模型,给出五种典型工况,作为绞车及支架设计载荷工况条件,为绞车支架设计奠定基础；基于人机工程学原理,结合我国绞车手、救生员身体标准,进行绞车支架的结构尺寸及外形设计,并利用ANSYS Workbench软件对其在五种典型受力工况下的结构强度进行分析。分析结果表明,支架最大位移和应力值都发生在载荷后偏30°工况,分别为1.25 mm和246.37 Mpa,均满足结构要求。(2)基于拓扑优化理论,利用ANSYS Workbench软件,对救助直升机绞车支架进行拓扑优化设计。设计案例分析表明,在应力和位移满足结构要求的前提下,拓扑优化后绞车支架的重量减轻12.5%,这将有助于提高直升机飞行的气动性能,减少飞行过程中的能耗和成本。(3)基于ANSYS Workbench软件,对拓扑优化后的直升机救助绞车支架进行模态分析,提取绞车支架前六阶固有模态和振型,与直升机旋翼旋转频率进行对比。结果表明,六阶约束模态基频的频率为475.24 HZ,振型为横向平面一阶整体摆动,而旋翼的激励频率为24 HZ,绞车支架与旋翼满足不发生共振的条件。(4)引入疲劳强度缩减因子,并利用Goodman曲线,修正绞车支架材料的S-N曲线,获得考虑形状、尺寸、表面状态、受载状况、平均应力等影响因素的绞车支架的S-N曲线；输入ANSYS Workbench中,分析获得绞车支架在加载脉动循环载荷下的寿命和安全系数云图。分析结果表明,在施加波峰值为极限工况下的脉动循环载荷后,对应循环次数大于107次,绞车支架具有无限寿命,满足疲劳强度要求。
[Abstract]:Helicopters have become an important equipment for modern land, sea life and property rescue. Rescue winch system is one of the key equipment on rescue helicopter, and its structure design affects the convenience, safety and reliability of lifeguard and winch driver in the rescue process. In this paper, based on ergonomics, topology optimization, modal analysis and fatigue analysis theory, the structural optimization design and analysis of winch support are carried out by using ANSYS Workbenc h finite element analysis software, in order to improve its operation convenience, dynamic and fatigue characteristics. The main contents are as follows: (1) on the basis of analyzing the working conditions and stress characteristics of helicopter rescue, the stress analysis model of winch and support is established, and five typical working conditions are given as the load working conditions of winch and support design, which lays the foundation for the design of winch support; Based on the principle of ergonomics and the body standard of winch driver and lifeguard in China, the structural size and shape of winch support are designed, and the structural strength of winch support under five typical stress conditions is analyzed by ANSYS Workbench software. The analysis results show that the maximum displacement and stress value of the support occur at 30 掳after load, which meet the structural requirements of 1.25 mm and 246.37 Mpa, respectively. (2) based on the topology optimization theory and ANSYS Workbench software, the topology optimization design of the support of rescue helicopter winch is carried out. The design case analysis shows that under the premise that the stress and displacement meet the structural requirements, the weight of the winch support can be reduced by 12.5% after topology optimization, which will help to improve the pneumatic performance of the helicopter flight and reduce the energy consumption and cost during the flight. (3) based on ANSYS Workbench software, the modal analysis of the helicopter rescue winch support after topology optimization is carried out, and the first six natural modes and vibration modes of the winch support are extracted. The rotating frequency of helicopter rotor is compared with that of helicopter rotor. The results show that the fundamental frequency of the sixth constrained mode is 475.24 HZ, while the excitation frequency of the rotor is 24 HZ, winch support and rotor satisfying the condition of no resonance. (4) the fatigue strength reduction factor is introduced, and the S 鈮，

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