汽车横向稳定杆轻量化设计方法研究

以某车辆的横向稳定杆为研究对象,通过将仿真结果与理论计算得到的稳定杆杆臂端部位移和应力分布进行对比,检验了有限元分析的可行性;通过ISIGHT软件对CATIA和ABAQUS集成,设定横向稳定杆的杆臂长度、杆件外圆直径和内圆直径为变量,采用NSGA-II遗传优化算法实现了横向稳定杆的轻量化设计。对轻量化结果再次进行有限元仿真,结果表明,轻量化后横向稳定杆质量降低了18.1%,应力降低了7.1%,侧倾角刚度提升了26.4%,在大负荷工况下疲劳寿命提升了14.8%。研究结果既实现了横向稳定杆的轻量化,又提升了横向稳定杆的刚度和使用寿命。研究方法为同类产品的有限元分析及轻量化设计提供参考。     

轿车前横向稳定杆刚度与疲劳寿命分析

前横向稳定杆是汽车悬架系统关键结构件,其疲劳断裂严重影响了车辆行驶安全性。本文以某款轿车的前横向稳定杆为例采用数值计算和有限元分析法分别计算了前横向稳定杆的刚度,并进行了对比分析,采用数值计算法对前横向稳定杆的应力与疲劳寿命分析,为轿车前横向稳定杆的设计提供理论参考。     

考虑横向稳定杆的车架有限元分析

介绍了稳定杆有限元建模的要点,在建立了包括横向稳定杆在内的重型载货车车架有限元模型的基础上,讨论了稳定杆对车架强度和刚度的影响。包括横向稳定杆在内的车架结构分析模型的建立,对重型载货车车架设计有实际意义。     

汽车横向稳定杆疲劳寿命分析及其优化设计

为了解决某横向稳定杆断裂失效问题,首先基于有限元方法和刚柔耦合多体动力学建立前横向稳定杆总成模型和前悬架动力学模型,提取其极限工况时横向稳定杆两端上下跳行程,获取强度分析的强制位移为49.5 mm。然后基于Nastran软件对横向稳定杆进行强度分析,分析结果表明其最大应力为977.6 MPa,位于横向稳定杆与稳定杆支架、衬套相连接位置,存在疲劳损伤风险。采用Femfat软件对横向稳定杆进行疲劳寿命分析,分析结果表明其最小寿命为3.37×10~4次,最薄弱处与强度分析最大应力位置一致,低于设计要求值。再通过Isight优化集成平台对横向稳定杆直径进行多目标优化分析,获得了其最优直径,同时其疲劳性能满足设计要求。最后建立横向稳定杆台架试验平台,以正弦波进行加载,试验表明优化之后横向稳定杆试验结果与疲劳仿真结果相吻合,并且通过了整车道路试验,最终成功解决了该横向稳定杆断裂故障问题。该分析方法结合了有限元、多体动力学、疲劳力学、台架试验和路试验证,为类似结构件疲劳强度分析以及优化设计提供了先进的科学指导。     

燃料电池轿车后横向稳定杆的轻量化设计

为达到对后横向稳定杆减重的目的,讨论了两种减重方案,一种是将原来的实心杆做成空心结构,另一种是直接将稳定杆的外径减小.首先,用三维软件完成稳定杆的3维模型,再利用有限元分析软件HyperWorks分别分析和比较两种方案的应力与形变、模态及扭转刚度,最后在虚拟样机ADAMS中建立整车模型,通过典型工况模拟两种轻量化方案对整车性能的影响.在保证原车性能的前提下,优化选择适当的轻量化设计方案.     

横向稳定杆刚度对乘用车操纵稳定性的影响研究

针对横向稳定杆对乘用车的操纵稳定性影响的问题,对横向稳定杆与整车抗侧倾能力的关系进行了研究。提出了一种简化的乘用车数学模型,并建立了整车侧倾角与横向稳定杆刚度的函数关系;通过对某乘用车简化数学模型的分析,得到了横向稳定杆刚度对整车侧倾的影响,并基于ADAMS仿真软件,对某乘用车进行了整车建模,在中间位置转向和稳态回转两种工况下进行了试验仿真,得出了前桥/后桥横向稳定杆刚度对该乘用车操纵稳定性的影响规律曲线。仿真分析结果表明:随着横向稳定杆刚度增加,车架侧倾角呈非线性递减,侧倾角曲线斜率逐渐减小,仿真结果与理论建模分析结果一致,为乘用车横向稳定杆的刚度设计提供了理论依据。     

应用变刚度横向稳定杆的客车侧倾控制

针对空气悬架客车侧倾稳定性差的特点,建立了含横向稳定杆的车身侧倾数学模型,分析发现增加横向稳定杆角刚度能够有效减小车身侧倾,但同时会增加车身侧倾角振动。为解决这一问题提出了在空气悬架客车上应用变刚度横向稳定杆,并给出了前、后悬架变刚度横向稳定杆角刚度关系式。利用ADAMS/CAR软件建立某空气悬架客车刚柔混合整车动力学仿真模型,对模型进行了单移线和B级随机路面仿真分析,确定了变刚度横向稳定杆角刚度曲线。仿真结果表明,应用变刚度横向稳定杆,能够在几乎不影响侧倾角振动的前提下,有效控制车身侧倾。     

ANSYS Workbench二次开发在汽车稳定杆CAE分析中的应用

为简化汽车稳定杆分析流程、提高工作效率,同时让设计人员快速掌握汽车稳定杆的有限元分析操作方法,以Delphi语言为编程工具,对ANSYS Workbench有限元分析软件进行二次开发。经二次开发后的ANSYS软件导航工具,界面友好,可快速进行汽车稳定杆的应力、应变、刚度及强度的有限元分析。     

横向稳定杆对搅拌车稳态响应的影响

运用Trucksim软件建立重卡搅拌车整车模型,并进行稳态回转仿真与试验,验证模型的准确性。通过对汽车的侧倾状态进行理论分析,可知前后悬架横向稳定杆刚度匹配影响车辆前后轴的侧倾刚度,从而影响汽车的稳态响应特性。最后对横向稳定杆不同布置方案进行仿真分析,并通过了试验验证。结果表明:前桥增加横向稳定杆有利于整车的不足转向与抗侧翻能力,提高工程车辆稳态特性。     

某乘用车备胎仓轻量化设计研究

以某乘用车备胎仓为分析对象,基于三维CAD软件对该备胎仓进行轻量化设计,主要包括对备胎仓进行拓扑优化及材料替换。接着采用有限元分析软件Hypermesh对两种轻量化方案的备胎仓进行有限元静力分析。在保证原有强度及刚度的前提下,通过拓扑优化后的备胎仓质量减轻了6.6%,通过材料替换后的备胎仓质量减轻了55.7%。通过综合对比,采取材料替换的轻量化设计方法综合性能优于拓扑优化。将替换材料后的备胎仓进行装车路试,进一步验证了有限元分析结果的准确性。实现了备胎仓的轻量化设计,为后续的备胎仓轻量化设计提供了新的设计思路。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.