基于ANSYS的自动模切机主机墙板的应力分析和结构优化

在正常工作情况下,高速自动模切机的主机墙板会受到很大的冲击,这会大大影响到模切精度,导致产品质量严重下降。应用有限元分析软件ANSYS对其进行有限元分析,掌握其应力和变形的分布情况,并在有限元分析的基础上进行结构优化,使得优化后的结构在刚度和强度上有很大的提高,从而有针对性地解决实际问题。     

注塑机模板的有限元—拓扑优化设计

传统设计的注塑机模板经常出现裂纹，针对这一问题，运用先进的ANSYS工程分析软件对注塑机模板进行有限元分析，找出应力和变形的分布情况，分析出断裂原因，并在有限元分析的基础上进行新颖的拓扑优化设计，使得优化后结构在刚度和强度上都有很大提高，从而有针对性地解决了工程实际问题。     

基于有限元的某转接齿轮箱的静动态特性分析

为了提高某测试试验台转接齿轮箱的传动精度和静动态特性,通过Abaqus有限元软件建立数值计算模型对其进行静动态特性分析。首先,通过有限元进行典型工况下的静力分析,得到受力与变形情况,校核其结构静态的可靠性;再通过模态分析,以确定其在试验台正常工作条件下发生共振的可能性,为之后齿轮箱的结构优化设计提供理论依据与指导。研究表明,该齿轮箱结构可靠且有很大的优化空间,可以进行结构优化来提高其传动精度以及静动态特性。     

基于结构优化设计的新算法研究

在开发优化软件过程中，采用模块化的设计方法，集成现有有限元分析软件，完成结构特性分析，提取其分析结果，调用高效的优化方法完成优化计算。所提出的结构优化设计算法充分利用了现有有限元分析软件强大的分析功能和高效优化方法的优越性，同时避免了优化程序设计中重复开发有限元分析部分，提高了优化效率。优化算例表明，该算法切实可行，有较强的工程实用性。     

基于有限元的五轴非正交摆头结构分析优化

基于非正交摆头结构的特点以及有限元软件,采用复杂结构简化及等效原则创建摆头结构的有限元模型,通过模型仿真计算出摆头的变形量和最大应力,找出刚度最小及应力集中的薄弱环节,并对其结构进行优化并分析验证。结果表明优化后的刚度提高及重量有很大的减轻,对整机的静态特性影响显著,实现了结构的设计优化及实际应用提供指导依据。     

TLJ400连续挤压机底座的结构分析与改进设计

运用Pro/E建立了TLJ400连续挤压机底座的三维几何模型,再转化到ANSYS建立底座的有限元模型,完成了正常工作情况下连续挤压机底座结构的有限元静力分析,掌握其应力与变形的分布情况.在分析计算结果的基础上,提出结构改进方案并对其进行了验证计算,使碍优化后的结构在强度和刚度上有很大的提高,结果表明有限元技术是连续挤压机底座结构设计的有效工具.     

桥式起重机箱形梁的结构优化设计研究

桥式起重机是起重机械的一种类型,它的性能很大程度上取决于其箱形梁结构.在对箱形梁进行全面的受力分析的基础上,建立了桥式起重机主梁结构的优化数学模型,并采用有限元软件Patran/Nastran和MMA算法程序对其进行了结构优化.最终,得到了满意的结果.     

注塑机模板的有限元——拓扑优化设计

传统设计的注塑机模板经常出现裂纹,针对这一问题,运用先进的ANSYS工程分析软件对注塑机模板进行有限元分析,找出应力和变形的分布情况,分析出断裂原因,并在有限元分析的基础上进行新颖的拓扑优化设计,使得优化后结构在刚度和强度上都有很大提高,从而有针对性地解决了工程实际问题。     

高位拣选叉车的运动仿真与有限元分析

为了保证高位拣选叉车在立体仓库中高效、安全地作业,采用虚拟样机技术和有限单元法对车辆结构进行了分析与优化。首先,通过虚拟样机技术对整车进行运动仿真,分析验证车辆的动态稳定性并为关键部件的有限元分析提供输入载荷;其次,对车架支撑臂、门架系统及货叉3个关键承力部件进行有限元分析,保证其强度和刚度满足工作要求。综合运用上述两种方法多次优化车辆结构,在很大程度上提高了车辆的综合性能。     

NJ6400白车身结构动力学分析及优化设计

利用有限元分析的方法对轿车白车身结构进行了动力学分析，通过改变车身结构情况分析计算，研究了车身结构与其固有频率和振动的关系，即进行有限元模型的灵敏度分析，最后对模型进行了优化设计。     

基于ABAQUS的表面微织构刀具切削钛合金仿真研究

利用有限元软件ABAQUS构建钛合金切削过程的二维仿真模型,通过钛合金切削试验验证模型的正确性。对微织构刀具切削钛合金的过程进行仿真,与无微织构刀具切削钛合金的仿真进行对比分析,研究了微织构刀具应力分布、切削力的变化规律以及对等效塑性应变的影响。仿真研究表明,微织构的存在对切削过程中刀具的应力分布有积极的改善作用,可以降低切削力,减少塑性应变。     

Experimental evaluation on micro-texture parameters of carbide ball-nosed end mill in machining of titanium alloy

Parametric optimisation of micro-texture is important to improve the performance of cutting tool in metal cutting. In this study, the simulation models of micro-textured surface of cemented carbide are established by using ABAQUS platform, and fictitious stress distribution is analysed to select the optimum micro-texture structure. Then, many friction tests were carried out to compare the several different micro-textures. Based on the experimental data, the parametric optimisation model of micro-texture on cemented carbide surface is established, and its significant analysis is carried out. Moreover, the optimised parameters are applied to the ball-nose end mill in the machining of titanium alloy. The results show that the micro-texture can absorb stress and change the status of stress distribution on the surface. Among the micro-texture structures, the performance of micro-pit is the best one, i.e. surface stress micro-pit-texture is distributed uniformly, and the stress concentration micro-pit-texture is low, when the micro-pit-texture’s diameter is 46.6 μm, its depth is 27 μm, and its distance is 123 μm. The ball-nosed end mill with the optimised parameters has a stronger wear resistance than a normal tool.     

预应力切削镍基高温合金的试验研究

针对镍基高温合金在切削后加工表面分布严重的残余拉应力等问题,提出采用预应力切削方法,以实现在加工过程中主动控制加工表面残余应力分布状态;通过研制轴类零件的车床专用预拉伸装置,在0 MPa、150 MPa和300 MPa三种预应力条件下对高温合金轴件进行预拉伸处理;通过硬质合金刀具预应力切削镍基高温合金的对比试验,对三种预应力条件下的切削力、切屑形态以及表面完整性包括已加工表面残余应力、加工表面粗糙度、表面形貌和显微硬度等指标进行对比。结果表明：在一定范围内,采用预应力切削方法可省去加工后续的残余应力调整工序,并能在加工表面获得合适的残余压应力;残余压应力的值可通过调整施加的预应力大小来进行主动控制;与普通切削相比,预应力切削可得到均匀的锯齿形切屑,切削力没有显著增加;预应力切削可获得良好的表面完整性,且不会引来额外的加工硬化。     

基于不同刀具前角金属直角切削的数值模拟

基于大变形一大应变理论、增量理论以及更新拉格朗日算法,建立二维弹塑性金属直角切削有限元模型;采用几何分离准则(距离准则)判断材料的分离,并自动对畸变网格进行重划分;通过用不同的刀具前角对金属直角切削过程进行数值模拟,分析总结结果,得出直角切削过程中在不同切削前角时切削力、刀具与工件的温度、应力应变的分布情况,为选用刀具形状、提高切削表面质量提供了理论依据。     

Experimental investigation of residual stress distribution in pre-stress cutting

This paper presents an analysis and experimental study on the formation and distribution of machined surface residual stress in pre-stress cutting. In the first component of the paper, the mechanical and thermal effect on residual stress is analysed. The results show that machined harden layer and cutting heat transfer conditions are crucial to form residual stress in a machined surface. Residual stress has three kinds of distributions in different mechanical and thermal conditions: tensile stress, compressive stress and tensile–compressive stress. If pre-stress is applied, it would facilitate residual compressive stress in the machined surface effectively; its action is analysed with an experimental study. The experiment is carried out by hardened 40Cr alloy steel turning with different tool rounds and pre-stress loading; the results obtained in this study indicate that the tool round would redound to generate residual compressive stress in the machined surface and affect the residual stress distribution significantly, whilst pre-stress load can affect the magnitude of residual stress actively, but does not for its distribution. It is found that the experimental results of residual stress distribution are consistent with the theoretical analysis.     

Tool edge radius effect on cutting temperature in micro-end-milling process

The cutting temperature plays an important role in micro-scale cutting process due to the fact that the dimension of the micro-cutter is small and the value of micro-cutter wear is sensitive to temperature. In this paper, the temperature distribution of the micro-cutter in the micro-end-milling process has been investigated by numerical simulations and experimental approach. Micro-end-milling processes are modeled by the three-dimensional finite element method coupling thermal?Cmechanical effects. The micro-cutter cutting temperature distribution, the effect of various tool edge radii on cutting force, and the effective stress during micro-end-milling of aluminum alloy Al2024-T6 using a tungsten-carbide micro-cutter are investigated on. The simulation results show that with increase of tool edge radius the cutting force increases, while the effective stress and mean cutting temperature decreases slightly. In increasing the tool edge radius, the maximum effective stress and cutting temperature region of the micro-cutter occur from the rake face to the corner on the tool edge and the flank face. The tool edge radius has been found to be the major factor affecting micro-cutter temperature distribution. The experimental verification of the simulation model is carried out on a micro-end-milling process of aluminum alloy 2024-T6 with a high-precision infrared camera. The influence of tool edge radius on cutting temperature distribution was verified in experiments.     

基于蒙特卡罗法的高速钢丝锥可靠性分析

高速钢丝锥主要失效原因之一是由断裂、崩刃所引起的破损失效,确定丝锥的可靠度对于自动化、高精密加工具有十分重要的意义。通过顺序统计量理论考虑丝锥受到冲击载荷的次数,并利用应力—强度干涉模型,以多次加工后切削刃上的最大扭转应力超过丝锥材料临界疲劳应力为失效判据建立高速钢丝锥的可靠度模型,并通过少量试验,结合蒙特卡洛法随机生成加工时分布在丝锥切削刃上的应力和丝锥材料临界疲劳应力,将得到的样本值进行比较,得出高速钢丝锥的可靠度。最终,通过恒应力加速试验对蒙特卡洛模拟法的计算结果进行了验证。     

Investigation on the burr formation mechanism in micro cutting

It is desirable to minimize burr formation for improving part quality. This paper presents an investigation on the burr formation mechanism in micro cutting by taking into consideration the stress distribution around the cutting edge arc. The influences of the uncut chip thickness and the cutting edge radius on burr formation were investigated. Poisson burr is attributed to the side flow of the stagnation material at the bottom of the cutting edge arc. The stress distribution at the cutting edge arc has great influence on Poisson burr formation. The burr height decreases to the minimum value and then increases with reducing the uncut chip thickness due to the change of the maximum stress distribution. An optimum machining strategy also is suggested in micro milling of snake-shaped groove microstructure.     

纳米切削过程中刀-屑接触区应力分布研究

高速切削时刀屑接触区的应力分布直接影响切削过程、切削温度及刀具磨损。利用分子动力学技术对纳米切削过程中刀屑接触区的应力分布特征进行研究,分别采用EAM势、Tersoff 势及Morse势计算单晶铜原子间、单晶硅原子间、工件原子与刀具原子间的相互作用力。分析纳米尺度下刀屑接触长度随切削距离变化的规律,探讨刀具前角对刀屑接触区应力分布的影响,通过描述刀屑接触区切屑原子的运动情况,为阐释刀屑接触区的应力分布特征提供依据。研究结果表明在刀-铜屑接触区,正应力在切削刃处最大,随着到切削刃距离的增大而减小,在刀-硅屑接触区,正应力以规则的波动形式逐渐减小。而切应力在切削刃处为负值,随着到切削刃距离的增大,切应力在刀屑接触长度的三分之二处增大到最大值后逐渐减小至零。     

对连续采煤机侧滚筒的有限元分析

为分析连续采煤机侧滚筒发生撕裂失效原因及估计其易发生位置,建立连续采煤机侧滚筒有限元模型,得到其应力分布云图.结果表明;在正常截煤工作和截割较硬矿岩时,滚筒不会因强度不足而引起撕裂失效,应力集中和材料缺陷是滚筒撕裂的主要原因.