基于THUMS(total human model for safety)下肢长骨有限元模型,在材料和单元属性等方面进行了改进.在详细分析行人下肢长骨载荷特点的基础上,采用多种不同载荷工况下较新的生物力学实验数据,对长骨模型进行了前-后和外-内加载方向的准...基于THUMS(total human model for safety)下肢长骨有限元模型,在材料和单元属性等方面进行了改进.在详细分析行人下肢长骨载荷特点的基础上,采用多种不同载荷工况下较新的生物力学实验数据,对长骨模型进行了前-后和外-内加载方向的准静态三点弯曲验证,同时对近心端1/3处、中部和远心端1/3处加载的动态三点弯曲验证.验证结果表明,该模型具有较好的生物逼真度,能够准确地模拟行人下肢长骨的骨折及碰撞响应,可用于后续行人下肢模型的开发,并为行人下肢损伤机理和安全防护研究提供准确高效的研究手段.展开更多
叶端定时(Blade tip timing,BTT)是一项具有应用前景的非接触式叶片振动在线监测技术,已有的BTT测量系统需要配备参考传感器来测量转速和提供时间基准。但航空发动机结构复杂及安装空间等限制,造成参考传感器安装困难,导致现有的BTT测...叶端定时(Blade tip timing,BTT)是一项具有应用前景的非接触式叶片振动在线监测技术,已有的BTT测量系统需要配备参考传感器来测量转速和提供时间基准。但航空发动机结构复杂及安装空间等限制,造成参考传感器安装困难,导致现有的BTT测量方法无法正常使用。针对无参考传感器叶片同步振动BTT测量及参数辨识方法展开研究,基于改进双参数法,在利用三个BTT传感器进行测量的条件下,对叶片振动位移差进行分析处理即可完成叶片同步振动幅值和倍频(Engine order,Ne)的辨识。结合数值仿真分析及试验研究的手段,将该方法与双参数法进行对比分析。结果表明,该方法能够准确辨识出叶片的振动参数,验证了其可行性和有效性,为无参考传感器BTT测量的工程应用提供了技术手段。展开更多
To improve the mainlainability design efficiency and quality, a layout optimization method for maintainability of multi-component systems was proposed. The impact of the component layout design on system maintainabili...To improve the mainlainability design efficiency and quality, a layout optimization method for maintainability of multi-component systems was proposed. The impact of the component layout design on system maintainability was analyzed, and the layout problem for maintainability was presented. It was formulated as an optimization problem, where maintainability, layout space and distance requirement were formulated as objective functions. A multi-objective particle swarm optimization algorithm, in which the constrained-domination relationship and the update strategy of the global best were simply modified, was then used to obtain Pareto optimal solutions for the maintainability layout design problem. Finally, application in oxygen generation system of a spacecraft was studied in detail to illustrate the effectiveness and usefulness of the proposed method. The results show that the concurrent maintainability design can be carried out during the layout design process by solving the layout optimization problem for maintainability.展开更多
文摘基于THUMS(total human model for safety)下肢长骨有限元模型,在材料和单元属性等方面进行了改进.在详细分析行人下肢长骨载荷特点的基础上,采用多种不同载荷工况下较新的生物力学实验数据,对长骨模型进行了前-后和外-内加载方向的准静态三点弯曲验证,同时对近心端1/3处、中部和远心端1/3处加载的动态三点弯曲验证.验证结果表明,该模型具有较好的生物逼真度,能够准确地模拟行人下肢长骨的骨折及碰撞响应,可用于后续行人下肢模型的开发,并为行人下肢损伤机理和安全防护研究提供准确高效的研究手段.
文摘叶端定时(Blade tip timing,BTT)是一项具有应用前景的非接触式叶片振动在线监测技术,已有的BTT测量系统需要配备参考传感器来测量转速和提供时间基准。但航空发动机结构复杂及安装空间等限制,造成参考传感器安装困难,导致现有的BTT测量方法无法正常使用。针对无参考传感器叶片同步振动BTT测量及参数辨识方法展开研究,基于改进双参数法,在利用三个BTT传感器进行测量的条件下,对叶片振动位移差进行分析处理即可完成叶片同步振动幅值和倍频(Engine order,Ne)的辨识。结合数值仿真分析及试验研究的手段,将该方法与双参数法进行对比分析。结果表明,该方法能够准确辨识出叶片的振动参数,验证了其可行性和有效性,为无参考传感器BTT测量的工程应用提供了技术手段。
基金Project(51005238)supported by the National Natural Science Foundation of China
文摘To improve the mainlainability design efficiency and quality, a layout optimization method for maintainability of multi-component systems was proposed. The impact of the component layout design on system maintainability was analyzed, and the layout problem for maintainability was presented. It was formulated as an optimization problem, where maintainability, layout space and distance requirement were formulated as objective functions. A multi-objective particle swarm optimization algorithm, in which the constrained-domination relationship and the update strategy of the global best were simply modified, was then used to obtain Pareto optimal solutions for the maintainability layout design problem. Finally, application in oxygen generation system of a spacecraft was studied in detail to illustrate the effectiveness and usefulness of the proposed method. The results show that the concurrent maintainability design can be carried out during the layout design process by solving the layout optimization problem for maintainability.
