车身结构的低噪声优化设计研究

在动态子结构修改方法的基础上,建立了车身结构的低噪声优化设计模型。然后,对某型国产轿车的车身乘坐室进行低噪声优化设计计算,并在计算结果的指导下进行降噪处理,获得了较为明显的车内降噪效果,同时也验证了所建立的优化设计模型的正确性和有效性。     

Discrete thickness optimization of an automobile body by using the continuous-variable-based method

Design optimization of an automobile body for dynamic stiffness improvement is presented. The thicknesses of plates consisting of a monocoque body of an automobile are employed as design variables for optimization whose objective is to increase the first torsional and bending natural frequencies. By allotting one design variable to each plate of the body, compared to previous works based on element-wise design variables, the design space of optimization can be reduced to a large extent. Because the present optimization is based on continuous-variable-based algorithms, considering manufacturability of the optimized result, the converged values of plate thicknesses should be approximated to commercially available discrete values. A new straightforward thickness discretization scheme considering design sensitivities and employing a subsequent reduced optimization problem is proposed. The validity of the proposed thickness discretization scheme is verified through numerical experiments.     

汽车齿轮变速箱阻尼减振降噪试验技术研究

通过传动装置阻尼减振试验研究,在分析国内外研究资料的基础上,确定传动装置阻尼结构方案,设计和制造相关试验件,选用阻尼材料,通过效果试验研究这些方案的有效性。     

汽车双万向传动中间轴的模糊优化设计

双万向传动中间轴在传动过程中,伴有速度波动,为减少速度波动引起的动载荷影响,设计时要在传递转矩一定的情况下,使中间轴质量最轻。讨论了中间轴设计过程中的模糊因素,建立了以截面积最小的模糊优化设计模型,运用模糊理论和方法获得最优解。     

基于多零件接触的重型汽车变速器壳体强度分析

以建立重型汽车变速器总成分析模型为基础,考虑零件接触问题对变速器壳体强度的影响,采用接触算法,对一倍额定转矩和三倍额定转矩负载下的壳体强度进行分析.分析结果表明,接触算法的约束相对于其它算法更接近于变速器的实际强度条件.变速器台架破坏性实验结果表明,接触算法分析得到的壳体强度薄弱区域与壳体实际强度薄弱区域相同.     

PU泡沫塑料汽车造型模型制作方法

针对高校汽车模型专业实验室现状,提出一种经济有效且对工艺要求较低的PU泡沫塑料汽车模型制作方法.针对PU泡沫塑料的特性,提出通过预盈余材料缓解材料剔除的不可逆转性,选用PU发泡填充剂及竹条解决了黏结强度的问题,介绍了一种处理PU泡沫塑料多孔表面的方法,通过模型制作验证了PU泡沫塑料作为汽车模型材料的可行性.     

A model of quantum noise in shadow radiation images

Correlation characteristics of a quantum noise in shadow X-ray images have been determined. A simple expression describing the structure of this noise has been suggested.     

汽车变速器模态分析及振动噪声测试实验研究

在PRO/E环境下建立SG13 5汽车变速器的 3D实体模型 ,应用I DEAS对变速器箱体进行动力学有限元分析 ,获得动力学参数。设计实验方案 ,测试和分析了箱体不同部位的振动与噪声信号 ,为变速器的减振降噪优化设计奠定了基础。     

定子曲线对汽车动力转向泵噪声的影响

通过反求,得出不同加工方法同类汽车动力转向泵定子曲线的差别。根据噪声测试结果,分析定子曲线对转向泵噪声影响。     

Parameter optimization of laser die-surface hardening using the particle swarm optimization technique

A method of multiple-objective optimization is proposed for parameter designing of laser die-surface hardening. The mechanical properties (wear resistance and hardness) and the geometrical properties (hardening depth and surface roughness), which control the hardening effect, are taken as the optimization objectives. A regression analysis is applied to build a non-linear equation for mapping the hardening parameters to the optimization objectives. Multiple constraints are analysed and a model of non-linear multi-objectives is established to optimize the parameters of laser die-surface hardening. The particle swarm optimization (PSO) technique is used for solving this optimization problem. The objectives are contradictive, since the laser die-surface hardening increases the surface hardness of the die, but increases the surface roughness as well. To overcome this problem, the surface roughness is set not only as an objective, but also as a constraint, so that a special fitness function is designed for the iteration of the optimal solution. The die of an auto body is used as an example to test the optimization of parameters. The optimization results show that the optimal parameters can be obtained using this method for laser die-surface hardening which satisfy the hardening requirement, and reduce the hardening time and cost.     

汽车动力性与燃油经济性模拟仿真与传动系参数优化设计

在对汽车动力性与燃油经济性进行研究、建立了动力性和燃油经济性的计算机模拟仿真的基础上,以动力性和燃油经济性为目标函数,绘制燃油经济性-加速时间曲线.并根据燃油经济性-加速时间曲线来优化动力传动系主减速比,从而综合改善动力性和燃油经济性.     

Design of the intake system for reducing the noise in the automobile using support vector regression

This paper proposes an optimal design scheme to reduce the noise of the intake system by using support vector regression techniques. For this, as a measuring tool for the performance of the intake system, the performance prediction software was used. Then, the length and radius of each component of the current intake system were selected as input variables and the L₁₈ table of orthogonal arrays was adapted as a space-filling design. The simulation of parameter design utilized an orthogonal array design, L ₁₈(2¹ × 3⁷). In order to evaluate the above design and levels, the experiments satisfying the condition were done. With these simulated data, we can estimate parameters in support vector regression by solving a nonlinear problem and finding an optimal level for the intake system by using support vector regression. This optimal design scheme gives noticeable results and is a preferable way to analyze the intake system. Therefore, an optimal design for the intake system is proposed by reducing the noise of its system.     

基于减振器神经网络建模的汽车悬架参数优化分析

利用神经网络对于非线性系统有很强逼近能力的特点,对减振器的外特性进行了神经网络建模.并将三种神经网络减振器模型分别放入整车Matlab/Simulink仿真模型中,对比分析了不同减振器对汽车平顺性的影响,从而确定了适宜被研究车型的减振器阻尼特性,使汽车在设计阶段就能完成悬架阻尼参数的优化匹配.     

四连杆抽油机传动机构的结构计算与优化

为了提高新型抽油机运动效率,以及实现最优的抽油机传动机构,利用现代设计方法,以SolidWorks2010软件为设计平台,建立了四连杆传动机构的初始实体结构模型,并对其进行了结构计算与优化设计,对比分析了质心坐标随时间的变化趋势,从中获得了四连杆传动机构优化前后质心轨迹坐标随时间变化的数据,以及质心X轴、Y轴坐标偏离支点的对比分析曲线,最终得到了抽油机传动机构的优化结构.研究结果表明,优化后的传动机构质心在X轴的坐标最大偏差可降低约85.87％,Y轴的坐标最大偏差可降低约92.42％,且运动变化较平稳,运动能耗降低明显.     

汽车自动变速换档规律的计算

介绍了自动变速汽车发动机和液力变矩器匹配的数学模型以及自动换档规律的数学模型;根据所建立的数学模型用MATLAB设计了程序对富康轿车进行了自动变速换档规律的计算。     

基于ANSYS的汽车传动轴的有限元分析

利用ANSYS进行传动轴的强度及刚度校核,给出相应的扭转应力、单位扭转角等数据有限元分析结果,在进行强度及刚度校核时,还将利用ANSYS进行验证。在相同的受力条件下,分别对实心轴和空心轴进行应力分析,分析出传动轴中空心轴和实心轴的性能优劣,为传动轴设计提供理论依据。对实际工程中选用有着重要参考意义。     

一种降低汽车后桥装配中齿轮噪声的途径

在微型汽车后驱动桥制造生产过程中,往往因各种因素导致啮合齿轮噪声超过工艺要求。笔者分析了噪声产生的原因,并提出降低其噪声的一种途径,实践表明在生产中采取这种途径取得了良好的效果。     

The noise reduction of a DC motor using multi-body dynamics

The DC motor of a vehicle may cause noise and vibration due to high-speed revolution, which can make a driver feel uncomfortable There have been various studies attempting to solve these problems, mostly focusing on the causes of noise and vibration and a means of preventing them The CAE methodology is more efficient than a real test for the purpose of looking for various design parameters to reduce the noise and vibration of the DC motor In this study, a design process for reducing brush noise is presented with the use of a computer model, which is made by using a multi-body dynamics program (DADS) The design parameters to reduce the brush noise and vibration were proposed using a computer model They were used to reduce the noise and vibration of the DC motor and verified by the test tesults of the fan DC motor in the vehicle This method may be applicable to various DC motors     

Improvement of substructuring reduction technique for large eigenproblems using an efficient dynamic condensation method

An accelerated substructuring reduction procedure for the iterated improved reduced system (IIRS) method is proposed. The iterated IIRS method can be combined with a substructuring scheme to provide an efficient methodology for large-scale eigenvalue problems. Not only can it reduce eigenvalue analysis errors through successive iterations, but the accuracy of the eigenanalysis is not sensitive to the selected master degrees of freedom. In practical structural eigenproblems, reducing the number of iterations can save a great deal of computation cost. The present substructuring technique modifies the iterative form of the transformation matrices in each substructure to achieve faster convergence. Applications of the present method to two numerical examples demonstrate that the proposed method can obtain lower eigensolutions of structures more accurately and efficiently, as compared with those of the current substructuring technique.     

汽车传动轴系动态拆装的制作

利用Catia软件简要讨论了汽车传动轴系动态拆装的制作.