新型串并联机器人的仿真设计

设计出了一种具有6自由度的新型串并联机器人,介绍了该机器人的结构和工作原理,并对该机器人的自由度进行了计算,之后对机器人进行了运动学分析,给出了其末端执行器的运动方程,最后对其进行了计算机仿真并对仿真结果进行了分析.     

基于Guyan法的有限元模型缩聚技术研究

简单介绍了Guyan缩聚方法的理论,设计了一个简单的算例,用此方法对其进行结构动力学模型修改.首先对算例模型进行了模态分析,其次进行了相关性比较,最后选择了三种不同的缩聚方案对理论模型进行缩聚,并对结果进行了分析,研究结论对有限元模型进行缩聚动力学修改具有一定的指导意义,研究问题的方法也值得推崇和借鉴.     

砌块成型机振动模态与谐响应分析及设计改进

对某砌块成型机进行了有限元建模,介绍了建模方法,通过砌块成型机的模态试验结果,对其进行了修正.分析了各阶模态振型.修正结果表明,砌块成型机模型能够反映其真实的动态特性,同时对振动台进行了谐响应分析,得出了砌块成型机振动台的理论振幅值,并对砌块质量进行了评价.最后根据现场测试对砌块成型机进行了结构改进.     

齿轮传动中间轴位置对轴承寿命的影响

对齿轮轴系的布局进行了初步探讨,对2种基本布局类型的轴承受力进行了对比,最后进行了实例分析.     

基于电机电流信号的滑动轴承摩擦状态监测研究

为有效预防滑动轴承的磨损失效,对滑动轴承的摩擦状态监测进行了研究。介绍了通过对电机电流信号进行经验模态分解、谱峭度分析,从而对滑动轴承摩擦状态进行监测的具体方法。同时介绍了油膜压降法试验原理,进行了油膜压降法试验,对试验结果进行了分析,并进行了镜像表面观察。通过对比确认,基于电机电流信号分析得到的滑动轴承摩擦情况与通过油膜压降法试验得到的结果基本一致,验证了基于电机电流信号进行滑动轴承摩擦状态监测的有效性。     

军用车辆动力系统技术特点及发动机选型研究

介绍了军用车辆动力系统的组成及使用要求,同时对其所用发动机的技术特点进行了阐述,并对其选型过程进行了重点研究。与转子发动机及燃气轮机进行了对比,内燃机具有高效、高可靠性、高耐久性及成本低廉等优势。对内燃机经选型后的改装过程进行了研究,最后对其进行了展望。     

往复泵曲轴强度及疲劳分析

根据往复泵曲轴受力分析的结果,利用ANSYS对曲轴的静强度进行了计算,对疲劳强度进行了分析,比较了两种材料的力学性能,对曲轴材料进行了优化选择。     

基于灵敏度分析的振动试验夹具优化设计

研究了固有频率对设计变量的灵敏度,设计了一个典型的汽车电器振动试验夹具,在进行灵敏度分析的基础上对夹具结构进行了优化设计.最后,进行了试验模态分析,验证了此方法的有效性.     

滚筒的应力分析与优化

本文应用有限元分析软件ANSYS对绞机的滚筒进行了分析,建立了等效力学模型和优化模型,进行了优化并对结果进行了对比分析。     

树脂基复合材料发动机机架结构研究

采用树脂基复合材料,对发动机执架的结构进行了设计,对结构进行了材料工艺及静强度试验研究.在设计分析的基础上,对纤维和树脂基体的筛选、优化进行了研究,对复合材料的基本力学性能和疲劳老化性能进行了研究.最后对大部件复合材料固化成型的工艺参数进行了优化,开展了机架结构连接方式和相关接头加工技术可行性研究.本文对树脂基复合材料在航天主承力结构上的应用进行了初步的探索和研究.     

再生式换热器的优化设计

指出以换热器流通面积,冷、热流体的接触面积之比,和转子转速等5个特征值作为优化判据,将换热设备的年运行费用作为寻优目标函数。运用Daridon.f.Powell罚函数的无约束化极小方法(SUMT)求解。避免了直接求导数的复杂的数学运算。并附实例优化计算结果列于表中,得出多种参数的最佳值。和优化结果。     

油气润滑最佳供油量研究

研究了不同的工况参数s与所需的润滑油供油量的关系,发现在不同工况参数s下都存在最佳的供油量.通过试验和分析,得到系统所需供油量与系统工况参数s之间的关系式,应用该公式可以预测轴承-主轴系统的最佳供油量.     

Optimum surface roughness in end milling Inconel 718 by coupling neural network model and genetic algorithm

In this study, optimum cutting parameters of Inconel 718 are determined to enable minimum surface roughness under the constraints of roughness and material removal rate. In doing this, advantages of statistical experimental design technique, experimental measurements, artificial neural network and genetic optimization method are exploited in an integrated manner. Cutting experiments are designed based on statistical three-level full factorial experimental design technique. A predictive model for surface roughness is created using a feed forward artificial neural network exploiting experimental data. Neural network model and analytical definition of material removal rate are employed in the construction of optimization problem. The optimization problem was solved by an effective genetic algorithm for variety of constraint limits. Additional experiments have been conducted to compare optimum values and their corresponding roughness and material removal rate values predicted from the genetic algorithm. Generally a good correlation is observed between the predicted optimum and the experimental measurements. The neural network model coupled with genetic algorithm can be effectively utilized to find the best or optimum cutting parameter values for a specific cutting condition in end milling Inconel 718.     

神经网络与进化策略在结构优化设计中的结合

利用BP神经网络对有限元计算出的样本数据训练出一种参数映射关系，从而获得进化策略求解结构优化问题的目标函数值，进一步获得问题的优化解，5杆结构表明此方法使用较少的有限元分析次数就能有效地求出最优解。     

Numerical optimization study to install air curtain in a subway tunnel by using design of experiment

Subways are a major mode of public transportation in metropolitan cities. A proper ventilation system is required to maintain indoor air quality in subway tunnels. Platform screen doors improve the platform environment but degrade air quality in subway tunnels. Trains transport fine particles from the tunnel into the platform. An air curtain installation in the subway tunnel permits traffic and reduces the transfer of bacteria and fine particles. The existing tunnel of Seoul subway was investigated by using computational fluid dynamics and design of experiment method for optimum air curtain installations. The flow field of the subway tunnel was computed by using ANSYS CFX software. Minitab software was used to generate the design process and to analyze the computational results. The computational domain of the existing tunnel included two natural ventilation shafts, one mechanical shaft, and the twin tracks. The height, width, and length of each track were 6, 4, and 400 m, respectively. The air curtain installation area was located between the natural and the mechanical ventilation shafts of Rrack 1. The design variables for the optimization study were the width, velocity, and installation location of the air curtain. The object function for optimization was mass flow rate at the natural ventilation shaft. The length of the air curtain was fixed at 4 m. The predicted mass flow rates were analyzed with the design variables by using the response surface method (RSM). The optimum values of the design variables, i.e., velocity, width, and installation location were 25 m/s, 0.2 m, and 5.8195 m, respectively. The maximum mass flow rate with the optimum design values was 114.4447 kg/s. The optimum values of the design variables were validated by computing the tunnel with the optimum values from RSM. The mass flow rate in the natural ventilation shaft 1 was 114.2 kg/s, as predicted. The optimization study can be helpful to set the optimum design conditions for the subway ventilation system.     

特征值反问题与机械设计

本文论述了多自由度系统的特征值反问题的迭代计算方法,与优化设计要结合,并应用于结构动力优化设计中带频率禁区的结构动力优化设计计算,为某些机械的结构动力优化设计,提供一种新的设计计算方法。     

基于刀具可靠性的切削用量优化

提出了基于刀具可靠性的切削用量优化新模型。用新模型得出的最佳切削用量优于用传统模型得出的切削用量。根据此模型，最佳切削用量随刀具可靠度水平的升高而降低；对于不同的切削过程，都存在着一组最佳的切削用量和一个最佳的刀具可靠度水平。提高刀具的固有可靠性可以有效地降低加工成本。刀具可靠度的水平越高，提高刀具固有可靠性的效果就越好。     

摆线针轮行星传动中摆线轮最佳修形量的分析与计算

通过对目前摆线针轮行星传动中摆线轮的修形方式进行了分析 ,提出了最佳修形齿廓的概念 ,对采用“负移距 +正等距”修形方法获得最佳修形齿廓原理进行了探讨 ,推导出了摆线针轮最佳修形量的计算公式。根据最佳修形量研制的样机通过试验也证明了修形理论的正确性     

摆线针轮行星传动中摆线轮最佳形量的确定方法

在对摆线针轮行星传动中摆线轮的修形方式进行分析的基础上,提出了最佳修形齿廓的概念,对采用"负移距+正等距"修形方法获得最佳修形齿廓原理进行了探讨, 推导出了摆线轮最佳修形量的计算公式.采用新齿形的样机试验结果也证明了修形理论的正确性.     

Optimization and graphical representation of machining conditions in multi-pass turning operations

This paper describes a procedure to calculate the machining conditions, such as the cutting speed, feed rate and depth of cut for turning operations with minimum production cost or the maximum production rate as the objective function. The optimum number of machining passes and the depth of cut for each pass is obtained through the dynamic programming technique and optimum values of machining conditions for each pass are determined based on the objective function criteria by search method application to the feasible region. Production cost and production time values are determined for different workpiece and tool material for the same input data. In the optimization procedure, the objective functions are subject to constraints of maximum and minimum feed rates and speeds available, cutting power, tool life, deflection of work piece, axial pre-load and surface roughness. By graphical representation of the objective function and the constraints in the developed software, the effects of constraints on the objective function can be evaluated. The parameters that are assumed to be most effective in determining the optimum point can easily be changed and the revised graph can be inspected for possible improvements in the optimum value.