轮胎性能对车辆操纵稳定性影响的仿真研究

本文中进行整车动力学仿真,以研究轮胎性能对车辆操纵稳定性影响。首先,对3组轮胎进行轮胎力学性能试验,利用所获得的力和力矩数据建立Unitire轮胎模型。然后,用Car Sim软件进行车辆动力学建模、仿真和试验验证。最后,利用所建车辆模型进行稳态回转试验、转向盘角阶跃试验和双移线试验,对试验数据进行分析,并客观评价了轮胎性能对车辆操纵稳定性影响。     

合理使用轮胎 确保行车安全

轮胎的磨损是车辆各个部件中最为频繁的,而轮胎出现问题直接影响的又是车主人身安全。 因此在日常轮胎使用时,合理使用轮胎,是确保行车安全的关键。 一、校正胎压:车辆轮胎胎压低于标准胎压行驶时,随着胎压的下降,轮胎与地面的磨擦成倍啬,胎温急剧升高,轮胎变软,强度急剧下降。这种情况下,如果车辆高速行驶,就可能导致爆胎。如果车辆在低速行驶,也会伤胎,而目潜伏期长,隐蔽性大,更有危害性,为以后高速行车时埋     

重型汽车空气悬架侧倾角刚度分配对稳态回转试验影响

前后轴侧倾角刚度的分配,会影响侧倾时车辆的轴荷转移,进而影响轮胎的侧偏特性,对车辆的稳态回转有重要影响。本文运用Adams/Car软件建立车辆的动力学模型,前悬架不变,匹配不同的后空气悬架侧倾角刚度,用定转弯半径法仿真分析对车辆稳态回转试验的影响。     

轮胎异常磨损的原因与对策

轮胎花纹中央磨损 产生原因车辆行驶中,由于轮胎充气过多,胎压过高,仅使轮胎胎面中央部分的花纹接触地面,也就是轮胎压花较少,从而导致胎面花纹的中央比两边部分磨损快.排除方法若出现轮胎花纹中央磨损时,需要检查胎压是否比规定值高,一般车辆的轮胎厂家都有规定的参数值,应调整胎压至标准范围内.     

科学保养轮胎上紧安全发条

车辆爆胎的原因缺气车辆轮胎缺气行驶是爆胎的主要原困。当轮胎胎压低于标准胎压时,随着胎压的下降,轮胎与地面的摩擦成倍增加,胎温急剧上升。轮胎变软,强度急剧下降,再加上车辆高速行驶,就可能导致爆胎。磨损车辆轮胎的磨损主要分为均匀磨损和不均匀磨损。轮胎在正常情况下磨损为均匀磨损。轮胎均匀磨损至胎侧的磨损指示标记时,不能继续使用,需要更换新胎。若轮胎胎面的磨损量不一致,磨损状况不均衡,这种现象就是轮胎的不均匀磨损。轮胎的不均匀磨损有胎冠中央磨损、胎冠两肩磨损、胎冠内侧或外侧磨损、胎冠锯齿状磨损、胎冠波浪状磨损或碟片状磨损、胎冠局部磨损等几种情况。如果发现轮胎磨损不均匀,说明轮胎的使用存在问题,需及时检修。对车辆轮胎磨损如果发现不及时、保养不到位,当行驶状况达到一定条件时,就会发生爆胎。     

工程车辆翻新轮胎承载变形特性

为了进一步明确工程车辆翻新轮胎的力学性能,提高其使用寿命,通过构建工程车辆翻新轮胎计算机几何模型、有限元分析模型、承载变形特性试验系统,对工程车辆翻新轮胎承载变形特性进行有限元分析及试验研究,并与同型号新轮胎进行对比分析,获得静态接地工况下工程车辆翻新轮胎的载荷-变形、载荷-刚度、载荷-压缩率等特性规律,构建26.5R25工程车辆翻新轮胎径向承载变形数学模型。研究结果表明：工程车辆翻新轮胎的径向变形、侧向变形变化规律与新轮胎接近,径向与侧向变形均比同型号新轮胎稍小;当胎压一定时,随着载荷的增加,工程车辆翻新轮胎径向变形呈线性增大,当胎压较低时侧向变形呈线性增大,当胎压较高时侧向变形呈非线性增大;工程车辆翻新轮胎的径向刚度及压缩率受径向载荷和胎压的影响较大,载荷一定时,径向刚度随胎压的增大而增大;胎压一定时,工程车辆翻新轮胎的压缩率随径向载荷的增大而增大,且稍小于同品牌、同型号新轮胎的压缩率;旧胎体的不同老化程度对工程车辆轮胎翻新后的承载-变形特性会产生较大的影响;在低载工况下,工程车辆翻新轮胎和新轮胎径向刚度差异不大,在接近标准载荷及高载工况下,工程车辆翻新轮胎径向刚度较新轮胎大,且随着载荷的增大,工程车辆翻新轮胎和新轮胎径向变形差异不断加大。     

行车途中轮胎的检查与保养

（1）随时检查胎压胎温。在车辆行驶一段里程后，应停车检查轮胎气压和温度情况。行驶时，随着胎压的下降，轮胎与地面的摩擦成倍增加，胎温急剧升高，轮胎变软，强度急剧下降。这种情况下，如果车辆高速行驶，就可能导致爆胎。所以，必须在行车途中经常去检查胎压、温度变化．一旦发现问题．     

商用车稳态回转试验陀螺仪安装位置对试验结果的影响

通过试验量化分析了陀螺仪安装位置对商用车稳态回转试验结果的影响,指出陀螺仪在质心处与其他处所得结果的不同,为今后稳态回转等车辆动力学试验的开展提供重要参考。     

如何正确使用轮胎

驾驶员在行驶和车辆勤务中做到以下几点,便能延长轮胎的使用寿命. 1、轮胎气压要适当,应保持生产厂所要求的气压标准.因为轮胎胎压低于标准胎压是造成轮胎脱皮的主要原因之一.据有关资料记载,轮胎气压低于标准值10%,则行驶里程将降低15%.另外,低于标准胎压的轮胎负荷后,遇坚硬障碍物时,将会使外胎内侧早期出现裂纹.这样,杂质便会乘机钻入裂纹之中,易使胎顶和胎肩起鼓包,发生脱皮.胎压过高,外胎易磨损,内胎易出现突爆,发生恶性炸胎,引发行车事故.     

车辆操纵稳定性客观评价指标的降维处理

影响驾驶员主观感觉的车辆运动量有很多,为研究驾驶员主观感觉与车辆客观运动量之间的关系,需要大量的试验样本,而在实际中往往很难实现.本文采用级别相当的两辆车,通过改变轮胎型号、胎压及配重质量等方法衍生出16种车型,完成相关的客观试验.利用丰成分分析方法,对所提出的客观指标做降维处理,从而降低主、客观一致性研究对试验样本量的要求,为主客观评价体系的一致性研究打下了基础.     

Study on Tire Dynamic Cornering Properties Using Experimental Modal Parameters

Based on the modeling of tire vertical characteristics and steady cornering properties, the model of tire nonsteady cornering is established in this paper using tire modal parameters extracted experimentally. In order to consider the influence of tire rolling effect on its cornering properties, the induced transfer function is introduced. The analytical formulae for calculation of transfer-function of lateral force and self-aligning torque with respect to lateral displacement and yaw angle are derived. The nonsteady cornering characteristics of tire under different loads can be calculated. The results of calculation are consistent with the experimental ones in the literature. The influence of rolling speed on tire cornering properties including the static case is analyzed. The nonsteady cornering properties in high frequency range are given by the model. The study demonstrates the consistency between steady and nonsteady tire modeling by using modal parameters.     

Study on Tire Dynamic Cornering Properties Using Experimental Modal Parameters

Based on the modeling of tire vertical characteristics and steady cornering properties, the model of tire nonsteady cornering is established in this paper using tire modal parameters extracted experimentally. In order to consider the influence of tire rolling effect on its cornering properties, the induced transfer function is introduced. The analytical formulae for calculation of transfer-function of lateral force and self-aligning torque with respect to lateral displacement and yaw angle are derived. The nonsteady cornering characteristics of tire under different loads can be calculated. The results of calculation are consistent with the experimental ones in the literature. The influence of rolling speed on tire cornering properties including the static case is analyzed. The nonsteady cornering properties in high frequency range are given by the model. The study demonstrates the consistency between steady and nonsteady tire modeling by using modal parameters.     

高速滚动汽车轮胎温度场的非稳态热分析

以试验数据为基础，分析了高速滚动轮胎温度场的非稳态热状况，应用最小二乘法对试验数据进行了拟合分析，建立了轮胎温升－时间历程关系式，并与理论计算公式作了对比，结果表明试验数据可靠；同时，分析了使用条件（速度、载荷、胎压及环境温度）对轮胎温升时间和大小的影响，结果表明，使用条件只影响轮胎温升大小，而不影响轮胎温升时间。用此方法建立了轮胎降温－时间历程关系式，分析了轮胎散热情况，分析表明温降时间也与使用条件无关。拟合关系式可用于初步预测轮胎温升及指导轮胎设计。     

汽车轮胎侧偏特性影响因素的试验研究

应用轮胎静力学特性试验机，研究了低速条件下3种不同胎面花纹轮胎在干燥路面上的侧偏特性，主要分析了胎面花纹、轮胎负荷和轮胎气压等因素对轮胎侧偏特性的影响。结果表明：轮胎的Fy-α关系曲线形状与胎面花纹形式、轮胎负荷和胎压等均无关。而Mz-α关系曲线变化趋势与胎面花纹无关，却与轮胎负荷和气压有关；在相同试验条件下，顺向花纹轮胎具有更优异的附着性能和侧偏特性。     

温度对共轨柴油机起动性能的影响

以Bosch第2代高压共轨燃油喷射系统为基础,建立了高压共轨试验测控系统.研究了进气温度和冷却液温度对高压共轨柴油机起动时间和排放性能的影响规律.试验结果表明,在不同起动油量和不同主喷油提前角条件下,进气预热有利于缩短起动时间、降低排放;在起动时间一冷却液温度曲线和HC排放-冷却液温度曲线上均存在最佳冷却液温度点,该点的起动性能最好.     

汽车轮胎二维稳态温度场的数值分析

通过对滚动轮胎进行合理假设，在MSC／PATRAN系统中建立了国产9．00—2012PR尼龙斜交轮胎二维稳态温度场有限元分析模型，用NASTRAN热分析求解器计算了轮胎的温度场分布，计算结果反映了轮胎的温度分布。通过拟合得到最高温升与车速的线性关系，该公式可以用来简单预测轮胎不同车速稳态的最高温升，对轮胎结构设计与使用有一定的指导意义。     

轮胎非稳态转向特性非线性仿真模型

本文以轮与路面之间的滑移速度为出发点，在稳态指数统一模型的基础上，建立了轮胎非稳态转向特性非线性仿真模型。在实验研究中，发现了动态过程回正力臂和附加的回正力矩的滞后特性。仿真和试验结果对比表明，该模型足以反映轮胎非线性转向特性，可用于前轮及汽车操纵动力学仿真方面的研究。     

Development of a valve and optimization of a tube for self-inflating tire

Worldwide, the tire market requires safe and eco-friendly tires. In this study, a self-inflating tire (SIT) was studied and manufactured. Self-inflating tire refers to a technique for maintaining appropriate tire pressure. An internal regulator senses when tire inflation pressure has dropped below the set air pressure. The tire boosts air through the valve when rolling and compressed air enters into the tire. This procedure keeps the tire air pressure at an appropriate level and increases tire safety. In this study, a regulator was used as a negative-pressure system. A check valve was selected the minute flow check valve depending on the shape of the configured system. In addition, the material of the tube was developed with excellent physical properties and resistances (elastic rebound, working temperature, etc.) owing to its complete compression and restoration. A tube performance tester was developed and a computer aided engineering (CAE) model was modeled for comparison with the test results. Using the tester and model, it was possible to optimize the shape of the tube and regulator. Finally, the reliability of the study was verified through the prototype test. The developed equipment and systems can be used for the manufacture of high-performance and safe tires.     

轮胎在水平路面上的自由滚动接触分析

利用轮胎的模态参数直接对轮胎在水平路面上的滚动建立了便于解析计算的仿真模型。该模型可模拟轮胎稳态的滚动过程并可计算出不小同工况下的滚动特性、有效滚动半径、载荷与下沉量的关系以及印迹内变形和分布力。计算结果揭示了以往模型难以描述的微观现象,与以往文献的试验研究结果定性一致,充分显示了模型的合理性。     

Validation of the 6-dof vehicle dynamics model and its related VBA program under the constant radius turn manoeuvre

For a 6-dof (degrees of freedom) nonlinear vehicle dynamics model and its related VBA (Visual Basic for Applications) program, which were recently derived and coded by the authors, validations are carried out under the constant radius turn manoeuvre. This model has the uniqueness that the longitudinal translation, lateral translation and yaw rotation of a platform are described by an inertial ground coordinate system and the body-roll, body-pitch, and body-yaw rotations by a platform-fixed coordinate system. The simplified STI tire model is applied for the calculation of combined longitudinal and lateral tire forces. Vehicles used in the calculation are a NISSAN DATSUN 210 (manufactured in 1980) and a HONDA ACCORD (1984). The calculation results of the present 6-dof model are compared with the published test data and those of a simpler 3-dof lateral dynamic equation based on another coordinate system. As a result of the comparison, the present 6-dof results agree very well with those of the 3-dof model and give a partial consistency with the test data.