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发表于 25-3-2010 15:59:08 | 显示全部楼层 |阅读模式

汽车零部件采购、销售通信录       填写你的培训需求,我们帮你找      招募汽车专业培训老师


由于 国 内 汽车工业的发展及人们生活水准的提高,人们对轿车的行驶速度的要求也不断提高。随着车速的不断提高,也带来了汽车操纵稳定性方面的问题。传统的悬架设计主要考虑行驶舒适性和接地安全性,这是由于当时的车辆多采用钢板弹簧,悬架具有自导向作用,而且汽车行驶速度低,各种行驶工况下悬架的变形小,所引起的车轮定位参数的变化也小,因此以往只着重于悬架的减振性能,而忽略了它的导向性能。随着国内高速公路的发展,
现在汽车行驶速度明显提高了,车轮的跳动和转向引起的悬架的运动特性参数尤其是车轮定位参数的变化对操纵稳定性的影响已引起重视,汽车悬架的导向性能显得日益重要。汽车悬架运动学/弹性运动学规律设计成为汽车设计开发中的一项重要任务。本课题研究目的是通过研究建立轿车悬架运动学/弹性运动学特性的计算机仿真模拟分析系统,提供悬架导向性能的设计基础,为尽快掌握现代汽车悬架设计方法,增强悬架产品自主开发能力服务。
As the domestic auto industry development and the improvement of people's living standards, people speed car demand is also rising.As the speed continues to improve, it also brings the vehicle handling and stability problems.The suspension design of the traditional main consideration driving comfort and ground security, this is a result of vehicles to use more leaf springs, suspension with self-guiding role, and the vehicle speed is low, a variety of driving operating conditions of small deformation Suspension, caused by the changes in wheel alignment parameters are also smaller, so the previous focus on the suspension damping performance, while ignoring the performance of its orientation.With the development of national highways, and now vehicle speed obviously improved, the beating and steering wheel suspension caused by the movement parameters, especially changes in wheel alignment parameters of the effect of manipulation of the stability of attention, automobile suspensionPerformance-oriented become increasingly important.Automotive suspension kinematics / elastic kinematics law design for automotive design and development of an important task.The purpose of this research project is to study the establishment of car suspension by kinematic
/ Elastic kinematics of the computer simulation analysis system to provide performance-oriented suspension design basis, as soon as possible master modern automotive suspension design methodology, to enhance self-development capacity service suspension products.
第五章总结
'1 本课题的成功之处
  本课题以SantanaL X轿车为例,利用大型机械动力学分析软件ADAMS建立了麦克弗逊式悬架和复合式悬架运动学和弹性运动学计算机仿真模型,并通过试验提供了模型参数和对比结果。从动力学仿真计算和试验结果的对比中,可以看出在大多数工况下,计算结果和试验数据有一致的变化趋势,并且在常用载荷下的变化大小也比较吻合。这说明所建立的悬架运动学和弹性运动学模型已达到一定的精确度,可以为悬架的设计开发提供依据,尤其是对不同悬架方案的选型具有十分重要的指导意义。
The topics to SantanaL X cars, for example, the use of large mechanical dynamic analysis software ADAMS established Maike Fu Morrison-style suspension and composite suspension kinematics Kinematics and flexible computer simulation model and provides the model parameters by experiment and compare the results of.From the dynamics simulation and comparison of test results can be seen in most operating conditions, the calculation results and experimental data have a consistent trend, and the changes in the size of loads commonly used is relatively consistent.This shows that the established suspension kinematics and elastic kinematic model has reached a certain accuracy, can provide a basis for suspension design and development, in particular the selection of different suspension program of great guiding significance.
   从建模中知道,在ADAMS中所建悬架运动学l弹性运动学模型是参数化的,也就是说只要改变输入参数的值就可以方便地改变悬架的结构。利用这个三维参数化的模型进行悬架运动学和弹性运动学分析,使车轮定位参数变化的规律有利于汽车的操纵稳定性,就可以来优化设计悬架性能,指导悬架橡胶支承元件的设计开发,为悬架的优化设计奠定了一定的理论基础。
From the model we know that, in the ADAMS built in elastic l suspension kinematics Kinematics model is parameterized, meaning that as long as the change in the value of the input parameters you can easily change the suspension structure.Take advantage of this three-dimensional parametric model of suspension kinematics and elastic kinematics analysis, so that the variation of wheel alignment parameters are conducive to vehicle handling and stability, we can optimize the design since the suspension performance, to guide the design of suspension components, rubber bearingthe development of optimal design for the suspension has laid a certain theoretical basis.

'2 仿真模型中存在的问题
2. l 对运动学模型中存在的误差的探讨
运动学模型中存在的一个问题是未考虑悬架刚体的变形、橡胶支承的变形及各结构之间的间隙。运动学模型中把悬架简化成杆系结构,而各个杆件看成是绝对刚性的,铰点处也认为是只有纯转动而无任何橡胶件的变形,这样所得的结果就有一定的误差。但用弹性运动学模型来进行运动学模拟后发现,这个计算误差并不大。
Kinematic model is an issue exists in suspension rigid body does not take into account the deformation of the deformation of rubber bearing gap between the various structures.Kinematics model of the suspension be reduced to truss structure, but as each bar is absolutely rigid, hinge point is also considered to be only a pure rotation without any deformation of rubber parts, such results have a certain margin of error.However, elastic kinematics model to simulate the kinematic and found that this calculation error is not significant.
2. 2 对弹性运动学模型中存在的误差的探讨
弹性运动学模型中首先是橡胶件简化成三根两两垂直的弹簧,其中一根替代橡胶件的轴向变形,另两根垂直的弹簧替代橡胶件的径向变形。这种近似简化产生的误差,在弹簧小变形范围内误差较小,变形越大,误差越大;弹簧的原长越长,误差也越小。另外忽略了橡胶件的预紧力也会带来一定的误差。在橡胶件的小变形范围内,预紧力可以近似忽略不计,但变形量大的地方,橡胶件的特性曲线非线性较强,预紧力的作用较为明显。
Kinematics model of elastic rubber parts, first is the simplified three vertical springs 22, in which an alternative to rubber axial deformation, and the other two vertical springs alternative to radial deformation of rubber parts.Such an approximation to simplify the error produced in the spring within the framework of small deformation error of small deformation the greater the margin of error greater; spring's original length, the errors are smaller.Another overlooked piece of rubber preload will also have some error.Small deformation in the rubber parts within the preload can be approximately negligible, but the large amount of local deformation, rubber non-linear characteristic curve of a stronger, more obvious the role of preload.
     其次 ,在弹性运动学模拟中,把轮胎视为一个刚性体,没有考虑轮胎刚度,这也是产生误差的一个因素。
Secondly, in the elastic kinematics simulation, the tire as a rigid body, without considering tire stiffness, which is a factor of error.
  再次,如运动学模型中的杆件的弹性变形也是存在的,忽略了这些杆系的变形也会有一定的误差。尤其是后悬架是复合式悬架,横梁的跨度大,因此弹性变形较大,而且后悬架弹性运动学中的定位参数的变化量计算出的结果非常小,因而这个横梁的弹性变形所引起的误差相对较大,这也是后悬架模拟结果与试验结果的对比不理想的原因之一。
Once again, such as the kinematic model of the pole pieces of the elastic deformation also exists, and ignores the deformation of the truss will also have some error.Especially the rear suspension is a composite suspension, large span beams, so a larger elastic deformation, and the rear suspension kinematics positioning elastic parameters of variation calculated results are very small, so the elastic deformation of the beamerrors caused by relatively large, which is the rear suspension simulation results with the experimental results of the comparison is not the ideal one of the reasons.
     如前所述,前悬架中转向系的等效刚度的计算也是有一定误差的。转向系刚度对前束的影响较大。通过计算发现,在受纵向力和运动学工况,这根弹簧几乎不起作用,总的变形量只有0.001mm个数量级。在受侧向力的工况也只有0.2mm左右的变形,但在受回正力矩的工况,则若采用前述的线性弹簧,则变形量竟达到10mm之多,这样的计算误差就太大了,因此将此刚度进行修正后,计算结果就合理多了。当然,这样的近似修正也会存在一定的误差,还有转向系间的间隙也没有考虑,最好是通过试验来得到这一数据才能更精确。
As mentioned above, the front suspension in the steering system is the calculation of the equivalent stiffness of a certain error.Steering system stiffness on the impact of big toe.By calculating found by the vertical force and kinematic conditions, this root spring is almost ineffective, the total deformation is only 0.001mm orders of magnitude.In working condition under lateral force deformation of only 0.2mm or so, but the subject back to the moment conditions, then if the adoption of the foregoing linear spring, then the deformation actually achieve as much as 10mm, this calculation error was tooGreat, so this stiffness of the amendment, the calculation result is more reasonable.Of course, such amendments will be similar to a certain degree of error, as well as the gap between the steering system is also not considered, it is best to get this data through testing can be more accurate.
'3 对本课题进一步修改的建议
     对于以上所述的存在的部分误差,可以提出以下一些改进建议:
1.在模型中可以适当地考虑悬架杆件的刚度,尤其是对仿真结果较为重要的杆 件不用纯刚性件而用柔性件来建立模型,或者将它分成两个刚性件,用弹 性连接,弹性连接的刚度就用这杆件的挠度。例如,可以考虑将后悬 架中那根较长的横梁中间断开,左右两根之间就可以用一个柔性铰连接 。
In the model can be appropriate to consider the stiffness of suspension rods, especially for simulation results of the more important pieces of rigid rods do not have a pure and flexible parts used to build models, or it is divided into two rigid parts, elastic connections, flexibilityuse this connection stiffness on the deflection pole pieces.For example, you can consider a longer rear suspension beams in the middle of Okanagan disconnect, between about 2 can be connected with a flexible hinge.

2.用三根两两垂直的弹簧来代替橡胶件,应将弹簧的原长取得较大些,可以减 小误差。如果可行的话,最好能在弹簧上加上橡胶件的实际预紧力。
22 with three vertical springs to replace the rubber parts, springs should be greater access to the original length, you can reduce the error.If feasible, preferably with rubber spring on the actual preload.
3.通过试验来测定轮胎刚度,也就是说把轮胎的变形也考虑到课题中去。
Through testing to determine tire stiffness, ie the deformation of the tire also takes into account issues and going.

4.转向系的等效刚度也需通过试验来测定。
The equivalent stiffness of steering system also need to be measured by experiment.
通过 这些手段可以减小部分误差,使得所建的模型更符合实际情况。
By these means can reduce the part of the error, making the models built more in line with the actual situation.

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发表于 11-5-2010 16:21:39 | 显示全部楼层
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发表于 11-5-2010 21:10:15 | 显示全部楼层
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