轮胎花纹噪声及其降噪方法

从动力学观点阐述了花纹块和花纹槽的发生机理,对花纹块宽度和长度、花纹槽宽度、长度与走向、花纹条数、基本节距数、节距排列次序以及错位参数进行了分析,得出降低轮胎噪声的原理和方法.根据结构参数分析并结合模糊控制理论和遗传算法,提出了一种轮胎花纹结构参数进行优化的设计方法--模糊遗传算法.利用轮胎噪声仿真分析软件(TNS2002)和仿真优化软件(ODS002)进行轮胎花纹结构设计,达到了降低轮胎噪声的目的,同时也得到低噪声轮胎花纹结构方案.研究成果为低噪声轮胎花纹设计规范与方法提供了路径.     

变节距花纹轮胎噪声特性研究

采用主流的室内实验室转鼓方法对变节距花纹轮胎噪声进行了测试。对具有复杂花纹的乘用轮胎和载重轮胎的噪声频谱特性进行对比分析。对于乘用轮胎,轮胎花纹噪声随着速度的增加呈现一个偏于线性的增长趋势;对于载重轮胎,轮胎花纹噪声反而没有明显的增长趋势,曲线较为平缓;不同品牌乘用轮胎与不同品牌载重轮胎在标准速度下的1/3倍频程频谱曲线变化趋势有较大差异;与手工刻制的等节距轮胎噪声相比,成品轮胎所采用的变节距花纹结构设计有效地降低了各频段噪声峰值;对于变节距花纹成品轮胎,波浪形态横沟设计优于锐角形态,更优于正交形态;连通组花纹结构优于半连通组,更优于不连通组。文章为低噪声轮胎花纹结构优化提供了有意义的参考结论。     

基于用户偏好的体温测量仪造型设计

目的 研究体温测量仪造型特征与用户感性意象之间的映射关系,设计出符合用户偏好的体温测量仪。方法 以魅力工学理论为研究基础,运用评价构造法对目标用户进行访谈,整合收集的访谈资料,提炼出8项体温测量仪造型魅力因素,以及其包含的25项具体魅力形态特征,进一步运用数量化Ⅰ类理论,分析用户感性意象与体温测量仪魅力形态特征之间的映射关系,从而明确各个具体魅力形态特征对用户感性意象的影响程度,为设计出符合用户偏好的体温测量仪造型提供设计参考。结论 以实验研究结果为设计依据,完成体温测量仪的造型设计,通过对比实验对设计结果进行验证分析。结果表明,设计出的体温测量仪造型能很好地满足用户偏好,同时,可根据用户对体温测量仪的不同感知意象的偏好,有针对性地识别出相应的魅力形态特征,从而设计出满足用户偏好的体温测量仪。     

轮胎圆度误差检测系统的设计

针对轮胎圆度误差检测中需要消除偏心误差和表面形貌特征影响的问题,设计了一种基于激光三角法的轮胎圆度误差嵌入式检测系统.采用改良过的反向法误差分离技术采集轮胎轮廓信息并消除偏心误差;依据轮胎表面橡胶须和凹陷花纹的特点,设计了滤波和拟合算法消除其对检测结果的影响;应用最小二乘法评定轮胎圆度误差.对子午线轮胎大、小花纹表面的检测实验表明,系统可以有效消除偏心误差和轮胎表面特征的影响并完成轮胎圆度误差的检测.     

乘用车子午线轮胎泵浦噪声机理的实验-数值混合分析方法

汽车在中高速行驶(乘用车超50 km/h,卡车超80 km/h)时,轮胎噪声取代其他部分噪声成为行驶噪声的主声源。轮胎噪声产生机理主要分为三种:泵浦噪声、振动噪声以及空气动力学噪声。其中泵浦噪声与轮胎花纹设计有关,属于可设计噪声。如何确定声源的频谱特性,进而预测轮胎噪声仍然是一个难点问题。提出一种泵浦噪声源识别的实验-数值混合分析方法。其基本的假设是:花纹横沟在进入地面和离开地面时产生气流,花纹纵沟将该气流收集,在轮胎接地前端和后端辐射出噪声;该噪声的大小与轮胎和地面形成的声场有关,也和轮胎花纹的节距排列有关。所提出的方法包括雕刻花纹轮胎噪声测试、轮胎声场阻抗数值分析、以及声源辨识三部分;通过在频域反演噪声传播过程辨识不同横沟的声源;通过雕刻花纹轮胎进行了噪声实验验证,说明了本方法的有效性。     

三维GVT颗粒轮胎造型研究

颗粒轮胎造型是三维颗粒车辆——地面动力学（Granule Vehicle—Terramechanics,GVT）模型的前期研究,介绍了用颗粒构造三维GVT轮胎初始模型的过程,包括利用CAD实体造型技术建立参数化轮胎实体模型、轮胎颗粒的排布原则及其直径和坐标的计算,为GVT三维轮胎动力学模型提供了研究基础。     

一种实用的自由曲面上曲线插值算法

直接在自由曲面上构造曲线是非常实用的造型技术,实现在曲面上曲线插值的主要思路是将其转化为一般的曲线插值问题求解。基于曲面及其参数之间的对应关系,提出了一种实用的算法,即根据给定的曲面上型值点,首先在参数域平面上构造插值曲线,再将该参数域内插值曲线映射到曲面上,获得曲面上曲线,从而实现曲面上曲线插值的目的。给出了具体的算法步骤,并对参数曲线不在参数域内部的特殊情况进行了处理。图例显示该法具有满意的效果。     

腿障残疾人使用的电动三轮车造型设计

对残疾人的心理与生理特点进行了分析与研究,进行了电动三轮车的人机关系分析,给出了电动三轮车各部位具体的设计尺寸。在设计中考虑了安全因数,实现了无障碍设计与关爱性设计。研究了电动三轮车的造型与色彩之间的关系,给出了电动三轮车的色彩设计方案。整车造型采用仿生造型设计方法,实现了仿螳螂形态的腿障残疾人使用的电动三轮车的造型设计。     

对合Quantale范畴中的自由对象及其良幂性

本文首先给出了对合Quantale余核映射的概念,证明了任意子对合Quantale都是某对合Quantale余核映射的象。其次构造出了对合Quantale范畴IQuant中由集合生成的自由对合Quantale的具体结构,证明了遗忘函子 U:IQuant→Set有左伴随,并给出了其左伴随函子。最后,证明了IQuant中的单态射恰为单同态,得出了对合Quantale上的余核映射与其在范畴IQuant 中的子对象是一一对应的,从而证明了IQuant是良幂的。     

子午线轮胎胎面花纹块滑动磨损有限元分析

该文以205/55R16半钢子午线轮胎为参考轮胎,通过建立带纵向和横向简单花纹的轮胎模型,使用ABAQUS/Standard进行了轮胎自由滚动、制动工况的有限元分析,分析了与胎面磨损分布相关的粘着滑移区域随滚动角速度变化的分布情况。结果显示:轮胎在制动状态下,胎面各花纹块沿滑动方向前端出现接触大变形。但由于整体轮胎模型胎面花纹部分网格较粗糙,计算得到的花纹块变形受力分布特征不够准确。为此,采用整体到局部的分析方法,建立采用精细网格的二维平面应变花纹块模型,由整体轮胎模型提供其简化边界条件,使用ABAQUS/explicit进行了滑动的热力耦合有限元分析。结果显示:采用精细网格的局部花纹块模型能反映出滑动前端卷曲大变形以及表面卷曲自接触的变形特征。最后,通过模拟ABS(防抱死制动系统)控制下轮胎胎面花纹块磨损过程,分析了胎面花纹块沿周向的不规则磨损特征。     

Hydroplaning Analysis for Tire Rolling over Water Film with Various Thicknesses Using the LS-DYNA Fluid-Structure Interactive Scheme

Current work studies the transient hydroplaning behavior of 200 kPa inflated pneumatic radial tires with various types of tread patterns. Tires were numerically loaded with a quarter car weight of 4 kN, and then accelerated from rest rolling over a water film with a thickness of 5, 10 and 15 mm on top of a flat pavement. Tire structure is composed of outer rubber tread and inner fiber reinforcing composite layers. The Mooney-Rivlin constitutive law and the classical laminated theory (CLT) were, respectively, used to describe the mechanical behavior of rubber material and composite reinforcing layers. The tire hydroplaning phenomenon was analyzed by the commercial finite element code - LS-DYNA. The Arbitrary Lagrangian & Eulerian (ALE) formulation was adopted to depict the fluid-structure interaction (FSI) behavior. Three different tire tread patterns, i.e. the smooth (blank) tread pattern and the 9 and 18 mm wide longitudinally-grooved tread patterns, were constructed to perform the current transient hydroplaning analysis. Simulated dynamic normal contact force and hydroplaning velocity of tire with a prescribed smooth tread pattern were obtained. The computed results were in good agreement with the numerical and test results given by Okano, et al. (2001) for tire running over 10 mm thick water fluid film. In addition, dynamic contact force of a smooth tread pattern tire rolling on a dry flat pavement was also found to be close to the result reported by Nakajima, et al. (2000). In addition, the effect of fluid water layer thickness on the hydroplaning velocity and normal contact force for tires with smooth tread pattern and longitudinally-grooved tread patterns rolling on a wet roadway analyzed by the LS-DYNA code are reported and discussed.     

不同花纹轮胎噪声辐射特性

轮胎噪声是交通环境噪声的主要来源之一,也是汽车噪声的主要声源。用虚拟模型预测的方法对滚动轮胎的振动辐射噪声进行预测分析。通过对滚动轮胎施加路面简谐激励,获取滚动轮胎表面加速度响应并作为声学分析的边界条件。采用边界元的方法分析不同花纹形式的滚动轮胎在路面激励下振动辐射噪声特性,结果表明花纹形式直接影响着滚动轮胎振动辐射噪声的大小,胎面花纹质量越小,振动辐射噪声越大,研究结果具有工程应用价值。     

Optimum shapes of tire‐treads for avoiding lateral slippage between tires and roads

Optimum design of tire‐tread sections is an important practical issue. However, useful study of the problem that can suggest a reliable guideline for determining the optimum tread sections had hardly been made in the past. The present paper describes a new analysis of the state of stresses in tire‐tread sections in contact with the road surface, taking special care of the boundary conditions. Based on the analysis, a method is proposed to determine the optimum tread shapes for avoiding lateral slippage between tires and roads. The displacement potential function formulation, an ideal mathematical model for the practical stress problems, has been used in conjunction with finite‐difference method of solution. For the present analysis, lateral slipping in absence of frictional resistance as well as the no‐slip conditions of the tire‐tread contact surface have been considered along with a large number of tread aspect ratios. The present computational approach proves to be a powerful tool for determining the optimum tread shapes for avoiding the lateral slippage of tire‐treads. Copyright © 2005 John Wiley & Sons, Ltd.     

The “intelligent tire” utilizing passive SAW sensorsmeasurement of tire friction

The term “intelligent tire” describes tires equipped with sensor systems to monitor thermal and mechanical parameters while driving. Information about temperature, tire pressure, tread wear, etc., is collected and used for car operation and maintenance support. The contact between tire and road surface is a key parameter when characterizing the ability to accelerate, decelerate and steer a vehicle, therefore making contact monitoring important for modern car control systems. Following numerous previous theoretical works, the friction coefficient can be measured by evaluating the mechanical strain in the tire surface contacting the road-utilizing the deformation of the tread elements. A new monitoring method using passive radio requestable SAW sensors is presented. The principle, measurement setup and experimental results are shown     

家猫爪垫减振机理及其在轮胎花纹中的仿生应用研究

猫科动物运动时表现出极强的减振特性,爪垫作为与地面接触的唯一躯体部分是影响减振效果的关键因素.通过对家猫爪垫的组织学和接地力学试验研究表明,爪垫的减振机理主要体现在:爪垫组织结构呈现的多层特征有助于衰减接地应力;正常行走步态下爪垫力学特性表征出的爪垫-地接触中存在摆动变形的运动特征有利于缓冲储能的发挥.利用家猫爪垫的减...     

轮胎自激振动分岔参数影响分析

如何避免轮胎的非正常磨损是汽车研发设计过程中迫切需要解决的问题之一,而胎面的自激振动是其中的重要影响因素之一。考虑轮胎接地磨擦的非线性迟滞特性,采用Lugre摩擦力模型,建立了考虑时间延迟的轮胎磨损振动模型。通过matlab/simulink进行仿真试验,验证了汽车中高速行驶时硬自激振动现象的存在;找到了容易引起自激振动的敏感参数并研究改变敏感参数范围对自激振动的影响规律,得到载荷越大,接地块质量越小,前束角越大,胎面越容易出现自激振动现象的结论。所建立的动力学振动模型为减小或消除轮胎的自激振动提供了理论依据     

Stabilized numerical solution for transient dynamic contact of inelastic solids on rough surfaces

A simulation technique to deal with transient dynamic contact of tire rubber compounds on rough road surfaces is presented. The segment-to-surface approach is used for modeling the contact between tire tread rubber and road track. While the rubber components are deformable and described by a sophisticated viscoelastic damage constitutive model, the road surface is assumed to be rigid and characterized by an analytical function. A spectral approach based on an inverse computation of the 2D-Fast Fourier transform has been suggested for the reconstruction of rough surface profiles. The Newmark time-stepping method is used for the integration of transient dynamic equations. With the so-called contact-stabilized Newmark method the spurious oscillation at contact boundary has been removed. The detailed investigation on the dynamic contact of inelastic rubber block with rough road surfaces has been made. The robustness of the contact-stabilized Newmark method within a finite deformation framework is underlined by numerical studies, in which it is compared with several dissipation-based stabilization techniques selected from literature.     

基于MLE的滚动轮胎冲击振动噪声仿真分析

提出一种滚动轮胎冲击振动噪声预测的新方法。轮胎滚动接触引发的噪声是道路交通的一个重要课题,引发广泛关注,目前尚没有有效的分析预测方法。提出新方法包括用混合拉格朗日—欧拉描述法(Mixed Logrange Euler Method,MLE)分析大变形滚动接触结构的速度场、加速度场和接触变形。通过欧拉网格和拉格朗日网格的信息传递,完成滚动结构动力学分析。通过将轮胎花纹和胎冠整体三维建模,可以得到连续轮胎表面的加速度场。以参考空间中连续表面的加速度场作为声源,采用声学有限元方法得到滚动噪声的分布预测。实验和仿真结果对比证明本方法的可靠和准确,也证明1 000 Hz以下轮胎的滚动噪声主要是花纹的冲击振动引起的噪声。提出的方法为预测分析轮胎的滚动噪声开辟一条可行的道路。     

Failure analysis of tire tread separations

In-service catastrophic radial tire failure is often a separation of the tread and outer steel belt from the tire casing and inner steel belt. These separations generally occur in the field at high temperature and high speed. This paper presents a catalog of surface characteristics that define the various types of rubber cracking that take place during a tire belt-leaving-belt separation. A mechanism that explains the generation of the rapid tearing surface is used to detail the variation found in forensic examinations.