基于Hyper Mesh的商用车驱动桥壳有限元分析

驱动桥壳是汽车的重要部件之一,应具有足够的强度和刚度。先利用UG建立桥壳的几何模型,然后在Hyper Mesh中进行网格划分、加载和约束,对驱动桥壳进行有限元分析计算,最后提出改进方案。     

Evaluation of dynamic fracture toughness parameters of locomotive axle steel by instrumented Charpy impact test

The analysis of the energy of fracture of specimens from steel OSL, which is widely used for the manufacture of railway axles under shock loading, is performed. The nature and quantitative parameters of the typical stages of the processes of plastic and brittle fracture, depending on the test temperature and stiffness of the stress state at the tip of the crack‐like defect, are established. It is shown that impact loading at 20 °C leads to the formation of the local zone of plasticity and ductile–brittle fracture of the material. An increased stiffness of the stress state at the tip of the defect at ?40 °C causes brittle fracture. An approach is developed, which is based on using the size of shear lips as a quantitative parameter of fracture under normal and low temperatures, similar in its physical essence to deformation approaches of nonlinear fracture mechanics. Based on this approach and the quantitative analysis of specimen fracture zones, the physical and mechanical scheme of specimen fracture is proposed in the presence of localized plasticity and in its absence near the tip of the concentrator.     

某螺旋簧结构驱动桥有限元分析

用有限元法计算分析螺旋簧结构驱动桥在多工况下的结构应力,找出结构薄弱环节并加以改进.     

飞机除冰车后桥壳有限元分析

针对中央液压驱动形式飞机除冰车的底盘开发,利用Solidworks和ANSYS软件,建立驱动桥壳三维模型,对驱动桥壳进行满载静力分析、模态分析和瞬态动力分析,找到驱动桥壳应力最大变形量的部位,得到其结构前10阶固有频率和相应的模态振型,发现后桥壳的振动规律,利用分析结果提出了在桥壳的一侧(前或后)或者两侧增加纵向稳定杆的改进建议。     

车辆轴载作用下半刚性基层沥青路面破坏潜力分级

针对不同轴载对半刚性基层沥青路面的潜在破坏能力问题,提出一种根据不同轴载作用下路面力学响应为标准的路面破坏分级方法。该方法应用弹性层状体系理论分析了不同轴载作用下的半刚性基层沥青路面力学特性,通过计算沥青层的抗剪强度、半刚性基层的拉应力和各结构层的压应力,并与标准轴载作用下结构层力学特性进行了比较,辅以各结构层的设计允许应力值,得到不同轴载作用下的路面破坏潜力表。通过对某公路安徽段实测数据的分析表明,该方法可以有效地实现不同轴载对半刚性基层沥青路面的潜在破坏能力分析。     

小波包滤波在齿轮故障诊断中的应用

为快速准确地判断齿轮故障的类型,提出了小波包滤波和神经网络相结合进行齿轮故障分类的方法。介绍了小波包去噪的原理和神经网络的设计方法,对阈值算法和神经网络优化算法作了改进,得到了不含噪声的信号和准确的故障分类方法。仿真结果表明,基于小波包滤波的神经网络方法具有更高的准确性和稳定性,可以满足工业故障诊断的要求。     

The Determination of Optimum Forging Conditions for the Production of High Strength-High Impact Toughness Automotive Parts

The influences of various reheating and forging temperatures as well as cooling rates on the microstructure and mechanical properties, particularly impact energy, during the forging of a Nb-V microalloyed steel to be used for automotive safety parts were investigated. Increasing the prior austenite grain size increased the volume percent of acicular ferrite and reduced pearlite content in the microstructure even for very low post-forging cooling rates, resulting in improved toughness and tensile strength values. Increasing the cooling rate enhanced the acicular ferrite content, thereby increasing the impact energy properties. At lower reheating temperatures the yield strength and impact energy levels are determined by the percentage of pearlite present in the microstructure; while as the cooling rate is increased the amount of acicular ferrite and retained austenite are increased, improving the toughness and tensile strength of the forged part. This effect is more pronounced for the parts solutionized at 1250°C and is related to the presence of very fine carbonitride precipitates under these conditions, which contributes to improved yield strength, particularly at higher cooling rates. An optimized forging process was determined and adapted to a 25 MN production forging press to validate the experimental results on semi-industrial production scale. By adequate control of the above parameters, high-strength, high-toughness parts (T.S. = 800 MPa, CVN = 35 J) were forged and optimum mechanical properties were achieved without the need for any additional heat treatment.     

高转速高精度机床主轴优化设计的研究

优化设计是一种新型的现代设计方法,它以提高产品质量、降低产品成本为宗旨。在对机床主轴进行力学分析的基础上,利用机械优化设计理论,构造了机床主轴的数学模型。以主轴重量为目标函数、以主轴的刚度为约束条件,对其变量进行寻优设计,解决了高转速高精度机床主轴优化设计的问题。     

DTM320／580型磨煤机传动齿轮轴断裂原因分析及防范措施

介绍了DTM580/320型磨煤机传动齿轮轴断裂的情况,并进行了分析;找到了断裂的原因,提出了防范措施。     

基于倒谱和小波变换的驱动桥故障特征提取

给出了一种驱动桥故障特征提取的方法，即无论驱动桥处于工作时的动态，还是非工作时的静态(采用锤击制造源信号)，所提取的信号都经过离散小波消噪处理，和小波包分解。对工作时的动态，需再用倒谱变换方法进行特征提取。此方法成功地解决了特征提取环境与工作环境不一致及动、静态故障特征提取方法差异过大的矛盾。用此方法提取的神经网络训练样本，会提高系统辨识的精确性。