基于有限元分析的NG3252自卸车货箱改进设计

针对某重型自卸车货箱在使用过程中由于自身刚度不足造成的侧板变形的问题及减重设计的需要,对其进行了改进设计。首先通过运动学仿真获得货箱处于最大受力状态的位置,利用该位置作为边界条件对货箱进行有限元分析,通过提高货箱底架的抗弯刚度减小侧板的倾斜变形。改进后的货箱保持原有的强度同时刚度提高。     

客车空调钣金框架断裂分析及改进设计

针对某公司客车空调钣金框架发生断裂失效情况,运用Pro/Engineer建立了框架3D模型,并通过有限元软件ANSYS对其进行应力分析,找出了最大应力和应力集中位置。有限元分析的最大应力位置和应力集中位置和实际发生断裂的位置完全一样。在此基础上对断裂框架提出了改进设计方案,改进后的框架其最大应力较原有框架的最大应力有大幅度降低,同时解决了断裂位置的应力集中问题。在实验室振动台对改进后的框架进行振动测试,测试结果表明,改进后的框架没有发生断裂情况。     

Simulating sliding wear with finite element method

Wear of components is often a critical factor influencing the product service life. Wear prediction is therefore an important part of engineering. The wear simulation approach with commercial finite element (FE) software ANSYS is presented in this paper. A modelling and simulation procedure is proposed and used with the linear wear law and the Euler integration scheme. Good care, however, must be taken to assure model validity and numerical solution convergence. A spherical pin-on-disc unlubricated steel contact was analysed both experimentally and with FEM, and the Lim and Ashby wear map was used to identify the wear mechanism. It was shown that the FEA wear simulation results of a given geometry and loading can be treated on the basis of wear coefficient−sliding distance change equivalence. The finite element software ANSYS is well suited for the solving of contact problems as well as the wear simulation. The actual scatter of the wear coefficient being within the limits of ±40–60% led to considerable deviation of wear simulation results. These results must therefore be evaluated on a relative scale to compare different design options.     

Ω形膨胀节及U形膨胀节强度和刚度的比较

膨胀节是为补偿因温度差与机械振动引起的附加应力而设置在容器壳体或管道上的一种挠性结构。应用轴对称单元建立相似几何参数的Ω形膨胀节和U形膨胀节的有限元模型,将上述两种膨胀节在內压载荷和轴向载荷作用下的强度和在轴向载荷作用下的刚度进行分析对比,发现按照JB4732-95标准,在承受內压时两种膨胀节的应力强度最大值均出现在倒圆角与筒体直边段相连处,Ω形膨胀节承受內压的能力稍大于U形膨胀节;而在承受轴向载荷时两种膨胀节的最大应力强度都出现在波峰中部,U形膨胀节承受轴向力的能力大于Ω形膨胀节;在同样的轴向力作用下Ω形膨胀节的轴向补偿量更大;而在满足强度要求的条件下U形膨胀节能达到的总的轴向补偿量更大。     

半挂式废钢运输车设计

介绍了一种新型转炉专用半挂式废钢运输车的设计,这种废钢运输车为钢铁厂转炉车间的废钢运输、冶炼提供了一种新型方式;采用有限元分析软件对拖车车架的强度进行了校核。     

斜齿轮有限元网格自动生成及齿根应力分析

将三维有限元网格自动生成技术与有限元分析软件ANSYS相结合,对斜齿轮加载方式和齿根过渡圆角进行分析。运用FORTRAN语言,并根据理论计算得到齿面点坐标,编制程序,建立斜齿轮三维有限元分析模型。全部算法实现程序化,只需输入齿轮的基本参数和网格控制参数,就能自动生成沿齿长和齿高均匀分布网格。然后将有关的节点和网格数据文件导入ANSYS,对比几种加载方式,确定最佳的加载方式,并针对几种齿根圆角,分析对比其对齿根弯曲应力的影响。     

桅杆式钻塔的模态分析研究

针对在钻探过程中,在多种复合的动载荷作用下,钻塔将发生振动和变形的问题,以桅杆式钻塔为例,对钻塔的动态性能进行研究。首先通过模态试验验证了模态仿真的正确性,然后分别从钻塔结构和动力头在钻塔不同位置两方面进行模态分析,获得了钻塔模态频率、振型随钻塔臂尺寸和装配距离的变化规律,分析了动力头在不同位置时钻塔的模态特征及其变化趋势。研究成果能对钻塔的结构优化及钻机的自动控制提供理论指导和数据支撑,同时有利于提升钻探效率,减少孔内事故。     

辊形对热连轧中间坯侧弯影响的有限元仿真分析

1700热连轧中间坯存在侧弯(镰刀弯)现象,对精轧机正常板形控制造成影响。现场检测发现粗轧机电动侧压系统夹钢坯负荷对中时偏移轧制中心线20mm。应用ABAQUS软件建立该粗轧机辊系变形有限元仿真计算模型,在偏移轧制中心线工况下,对支持辊与工作辊配辊辊形对板坯的楔形(侧弯)影响仿真计算。设计抗偏移干扰强的新的支持辊与工作辊配辊辊形,上机使用后,中间坯的侧弯(镰刀弯)现象有明显改善。     

一种高分子聚合物PCR芯片的设计及有限元分析

设计了一种以PDMS为基底的微型PCR芯片，并用有限元软件对芯片做了详细的温度场分析，主要分析了微型PCR芯片温度场的均匀性和分布以及芯片升、降温的效率。分析结果表明设计的聚合物芯片温度分布均匀，有较高的升、降温速率，可以满足PCR反应的要求。通过一维热传导理论分析，得到的结论与有限元分析的结果是一致的。     

A Theoretical Framework for Core Material Properties Identification in Cellular Solids using Novelty Detection

Abstract:  This paper presents a novelty detection-based technique to identify core material properties of honeycombs and cellular structures. A numerical model (finite element) representing full scale and/or reduced size of the cellular solid is used to generate transmissibilities between topological homologous points at cells in different locations. In order to make the procedure robust against noise, these transmissibilities are artificially corrupted. This step is representative of a series of experimentally obtained measurements which automatically return information relating to the size and shape of data noise along with the mean measurement. The next stage, both in this paper and in the proposal for the experimental approach, is to generate several further sets of transmissibilities from the finite element model; the only difference being that the core material properties are altered from the original values. A novelty detection framework is then adopted to find a similarity measure between each of these 'test' transmissibilities and the original set thereby identifying the material properties. Although this work is concerned with identifying only one material property, the methodology extends to identifying several properties.