Training effectiveness evaluation of helicopter emergency relief based on virtual simulation

Helicopters are playing an increasingly important part in emergency relief, such as earthquake rescue, firefighting and medical transport. With the development of virtual simulation technology, virtual simulation-based training is widely used in the training of the helicopter crew especially for the dangerous and costly missions mentioned above. A complete training effectiveness evaluation method is proposed to evaluate the trainees’ training effect based on virtual simulation in this paper. A key to this method is regarding the complicated process as a discrete event-activity flow system and establishing the evaluation indicator system. Then expert group and Analytical Network Process (ANP) are applied to determine the weight of indicators. When the training data are processed, there is a novel attempt to apply Fuzzy Comprehensive Evaluation (FCE) model to calculate the two categories of indicators. Eventually, an experiment and the analysis were carried out to validate the evaluation method.     

精密复杂零件的工艺设计过程分析

针对航天控制产品精密复杂零件的工艺难点,以该类零件的工艺设计过程为主线,分别论述了材料定额编制、工艺路线设计以及工序设计过程中的注意事项和工艺方案设计方法,并以实例进行了简要说明。     

三维编织复合材料及其RTM成型工艺

文章阐述了三维编织工艺,并将三维编织复合材料的性能与传统铺层复合材料的性能作了比较。同时,还介绍了其成型方法—RTM工艺的原理及特点,并提供了一种适于RTM工艺的树脂体系。     

碳/环氧复合材料两次表面镜基板研制

文章介绍了碳/环氧复合材料两次表面镜基板的结构与铺层、选材与成型工艺,性能测试等内容。     

缓磨时工件烧伤过程的计算机仿真研究

在关于缓磨时的磨削热、接触弧区换热过程以及工件表层非稳态温度场的深入研究的基础上构造了一个可用于计算工件表层温度场畸变历程的数学模型，并据此完成了缓磨时工件烧伤过程的计算机仿真研究。仿真结果与缓磨时的实际烧伤过程吻合良好。本文率先阐明了缓磨烧伤的热机理，并证实了缓磨烧伤是一典型的渐变过程，它有明显的前兆特征，因而是可以被预报和控制的。此项创造性工作可以被看作是对磨削基础理论的一项重要贡献。     

三角带失效概率模型

通过失效物理分析，考虑了挠性传动件-三角带的受力和变形．剖析了其失效形式．根据其特殊的失效物理背景推导了数学模型，提出宜采用最弱环模型，大样本试验证实了上述分析。     

A combined turbulent combustion model in studying a lean flameout process

A modification of the Zimont turbulent combustion model is presented; the modification makes it possible to describe processes in diffusion and homogeneous flame fronts as well as to take into account the influence of different factors that cause flame destabilization. The model is based on the equation for a reaction completeness extent (completeness of combustion). The model realization to simulate the premixed combustion is described and the modification of the turbulent combustion model is applied to simulate a process of flameout downstream of the flameholder.     

复合铣整体叶盘通道加工工艺规划分析

首先对开式整体叶盘通道几何特征进行分析,在宽度和深度上对通道加工空间进行计算,从轴向和径向进行切削加工性分析;通过偏置面求解及其延伸面求解,进而确定可加工区域;在对比分析各种铣削方法基础上,优选复合铣削数控刀具,明确通道复合铣加工方法以及流程,为后续开式整体叶盘通道加工工艺优化打下基础。     

基于虚拟仪器的切削力监控技术研究

研制了一种基于虚拟仪器界面、供现场使用的高精度、高效率的金属切削过程监控系统。研究中采用回归分析、叠加原理及抛物线插值的方法建立切削力模型 ,并基于该模型进行参数估计来提取切削状态特征 ,进而监控整个切削过程     

异种材料组合件精密组装及加工技术研究

文章介绍了某异种材料组合件的结构特点及工艺特点。通过对产品加工难点的分析,确定合理的装配及后加工工艺流程,设计了装配工装及后加工工装,加工出的产品形位精度最终满足设计指标。