液压挖掘机动臂内部筋板的拓扑优化设计

分析了液压挖掘机的典型工况及受力情况,并在铲斗挖掘工况下对其动臂进行了有限元计算。针对动臂内部筋板的布局,提出了一种箱型结构内部加强筋的布局优化方法,并基于渐进结构优化方法(ESO),对内部筋板的布局进行了拓扑优化,快速简便地确定了箱型结构内部加强筋的布局。对比优化前后有限元分析结果表明,此方法能够减小结构最大等效应力并减少高应力区。用试验验证了此方法的有效性和实用性。     

汽车车门内锁止有限元分析及结构优化

利用Unigraphics NX软件平台,对内锁止进行有限元仿真,分析其工作时受到的应力和位移。依据分析结果发现最大应力出现在凸耳根部,针对结构特点提出增大凸耳根部宽度并增添加强筋以求减小最大应力。实施结构优化后再次进行有限元仿真,对比前后两次有限元分析结果可知:该结构优化方案可有效减小内锁止工作时最大应力和位移,提高其工作可靠性和延长使用寿命,实现增强汽车安全性能的目的。     

大型振动筛侧板加强筋拓扑优化布局研究

为了优化大型振动筛侧板加强筋的布局,提出一种基于拓扑优化的侧板加强筋布局方法。建立以侧板刚度最大为目标的侧板加强筋布局的拓扑优化模型,根据拓扑优化所得伪密度分布云图对加强筋重新布局。对优化前后侧板进行模态分析和谐响应分析对比。与原侧板相比:新结构侧板的动应力下降56.5%,振动位移下降55.3%,一阶固有频率提高72.03%,各阶固有频率有效远离工作频率。     

多种脉动真空灭菌器的数值分析

对多种脉动真空灭菌器进行建模、求解和有限元分析。在内壁厚度、材料和工作压力等相同的情况下,重点对绕带式和夹套式结构、焊缝形式、加强筋的布局和种类等做对比分析。模拟结果表明在满足良好封闭性的前提下,绕带式灭菌器内壁上的最大应力值最小,为最理想的结构;对于夹套式结构来说,全焊缝应力集中值较小;断续对称焊缝好于交错焊缝;加强筋尺寸和型号选择灵活。整体来说,加强筋在内壁上均匀分布有利于降低最大应力,提高产品的使用寿命。     

某型民机复合材料机翼下壁板开口补强及优化研究

根据机翼结构设计要求,下壁板的层合板上开口是不可避免的。主要对民用飞机的机翼蒙皮下壁板开口补强结构进行分析,利用有限元分析软件MSC.PatranNastran建立二维复合材料有限元模型,模型采用壳单元。通过计算分析,对比了未补强壁板、补片补强和加强筋补强三种不同的方案情况下,机翼蒙皮下壁板在外载荷下的位移以及应力变化,及不同角度铺层的各层应力变化,研究了补强方式及铺层角度对机翼下壁板应力分布的影响。结果表明加强筋补强能较好减小位移和最大应力,避免应力集中;在采用加强筋补强方案时,-45°的铺层方向上应力最大;在设计机翼下壁板开口补强方案时应尽量选用加强筋补强,并尽量减少-45°方向的铺层。     

面向多目标满意度的分动器设计方案优选

由于分动器仅在四驱车辆上使用,以降低成本、提高传动效率和改善整车经济性为目标,提出了一种基于多目标满意度方法建立分动器设计方案的优选模型,实现分动器不同设计方案的有效优选。首先,考虑分动器设计开发流程与整车性能匹配的基础上,确定单轴无加强筋、单轴加强筋、双轴无加强筋和双轴加强筋4种备选方案。然后根据有限元分析结果和理论分析为基础,建立分动器设计方案评价的目标集,联合层次分析法确定目标集各因素对分动器设计方案优选的影响权重,从而建立分动器优选方案的多目标优化模型。最后运用多目标满意度决策机理,对不同分动器设计方案进行综合评估,得到的综合满意度最大的方案经验证合格即为优选的方案。该研究可为分动器设计方案优选提供参考。     

电动轿车电池箱体轻量化研究

提出一种形貌优化的电动轿车电池箱体轻量化设计方法。运用CAE有限元分析软件完成了电池箱体下板的单元离散、结构分析和形貌优化整个过程。以最大节点位移和最大单元应力为约束条件,分别以自定义多目标优化方程和单元总应变能为目标函数,完成了电池箱体下板形貌优化,获得了相应的加强筋布局方案,得出电池箱体优化后的结构形式。经分析计算,改进后的电池箱体下板结构力学特性更趋合理,重量减小61.39%,实现了轻量化设计的目的。     

基于ANSYS的高空作业车整车结构分析及实验验证

高空作业车是载人高空作业的专用车辆,安全性和可靠性要求高。为了准确计算某型号高空作业车整车结构强度和刚度,利用APDL语言,采用自底向上的建模方法建立了该车的参数化有限元模型,并选择了两种危险工况对整车结构进行分析。分析结果准确反映了整车结构在危险工况下的应力和变形分布规律,为高空作业车结构设计提供了依据。选取结构件的危险区域进行了应力测试,并将测试点的应力模拟值与实验实测值进行了对比,模拟误差在10%以内,验证了所开发整机模型计算的准确性。     

基于PATRAN的水配重罐体有限元分析

通过运用Patran对水配重罐体进行有限元分析,以检验原设计的可靠性。为增强水配重罐体的静力学性能,提出了在注水灌壁增加圆弧形加强筋、在注水灌底部与筒形支柱连接处增加纵向加强筋的形式,并对有无加强筋两种形式的水配重罐体进行静力学分析。通过对两种结构模型的总变形量和应力分析,证明加强筋可有效提高水配重罐体的静力性能。     

某钢板弹簧结构优化设计

钢板弹簧对于汽车的行驶平顺性、舒适性具有重要的作用。针对某汽车的特殊工作需求,开展了其后钢板弹簧结构的优化设计。首先基于有限元分析法,考虑相关参数,建立了后板簧的计算模型;其次对该模型进行了动力学强度分析,得到了板簧应力特征及其在特殊要求工况下薄弱环节;然后提出优化方案,以最大应力最小化为优化目标,对板簧进行结构优化,并对优化后的板簧进行动力学强度分析,对比说明优化方案的可行性及优点。研究结果表明:优化后的板簧结构满足材料许用应力要求,并且板簧总厚度改变不大,整车姿态不变。优化设计后的板簧试制并装车,进行耐久性考核试验,取得了满意的效果。     

Free vibration and buckling response of hat-stiffened composite panels under general loading

The paper presents finite element free vibration and buckling analysis of laminated hat-stiffened shallow and deep shells using arbitrarily oriented stiffener formulation. Modified approach for modelling the curved stiffener is implemented using necessary transformations. A simplified stiffener formulation is presented to accommodate various shapes of stiffener shapes in developing the rigidity matrix for the finite element formulation. Investigation has been carried out on free vibration and buckling analyses of laminated composite stiffened shell structures with laminated open section (rectangular or ‘T’ shaped) and closed section (‘hat’ shaped) stiffeners. Parametric study on the hat-stiffened panels for the free vibration and buckling analyses confirms that the closed section stiffener being torsionally rigid is found to show better performance over open section stiffeners.     

摄动有限元法在汽车传动系扭振分析中的应用

将摄动有限元法引入到传动系扭振分析中,介绍了用摄动有限元法分析传动系扭振的基本过程,为快速而有效的分析传动系扭转振动提出了新的研究方法。指出了用摄动有限元法修改传动系扭振结构的一些注意事项,并提出了研究过程中可能面临的一些问题及应对方法,对传动系扭振特性研究具有一定的指导作用。     

黄骅港定位车主臂钩头拉杆断裂故障的数值模拟研究

针对黄骅港二期翻车机作业过程中出现的定位车主臂钩头断裂故障，采用有限元软件进行模拟分析，根据模拟结果对故障原因进行总结，同时提出了有效的技改方案。     

某扭转梁扭转疲劳工况应力分析以及结构优化

针对某扭转梁在扭转疲劳试验过程中出现的裂纹现象,采用有限元法对扭转梁进行应力分析,结合计算结果给出优化改进措施,对该扭转梁的横梁加强板进行结构优化,横梁加强板开裂问题得到解决。     

Characterization of fracture behavior in repaired skin/stiffener structure with an inclined central crack

Finite element analysis for the stress intensity factor (SIF) at the skin/stiffener structure with inclined central crack repaired by composite stiffened panels is developed. A numerical investigation was conducted to characterize the fracture behavior and crack growth behavior at the inclined crack. In order to investigate the crack growth direction, maximum tangential stress (MTS) criterion are used. Also, this paper is to study the performance of the effective bonded composite patch repair of a plate containing an inclined central through-crack. The main objective of this research is the validation of the inclined crack patching design. In this paper, the reduction of stress intensity factors at the crack-tip and prediction of crack growth direction are determined to evaluate the effects of various non-dimensional design parameter, including; composite patch thickness and stiffener distance. We report, the results of finite element analysis on the stiffener locations and crack slant angles and discuss them in this paper. The research on cracked structure subjected to mixed mode loading is accomplished and concludes that more work using a different approaches is necessary. The authors hope the present study will aid those who are responsible for the repair of damaged aircraft structures and also provide general repair guidelines.     

A study on the development of equivalent beam analysis model on pedestrian protection bumper impact

This paper presents a dynamically equivalent beam analysis model on pedestrian protection bumper impact instead of a non-linear finite element impact analysis method. Equivalent beam analysis model was developed by substituting the femur and tibia for dynamically equivalent Euler beam. Dynamically equivalent forces of bumper beam, upper stiffener and lower stiffener are found by a finite element analysis results and applied to the Euler beam model of lower legform impactor. This equivalent beam analysis model was used to obtain a bending angle of lower legform impactor by using finite element beam theory. Peak acceleration of the tibia was obtained by developing an approximate acceleration equation. A linear interpolation of non-linear finite element analysis results considering the dimension variation of bumper beam factors affecting the acceleration was used to get an approximate acceleration equation. The accuracy of this simple analysis model was tested by comparing its results with those of the non-linear finite element analysis. Tested bumper beam types were press type beam and roll forming beam used widely in the current car bumpers. The differences of maximum acceleration of the tibia between the two models did not exceed 10% and the bending angle did not exceed 20%. This accuracy is enough to be used in the early stage of bumper beam design to check the bumper pedestrian performance quickly. Use of equivalent beam analysis model is expected to reduce the analysis time with respect to the non-linear finite element analysis significantly.     

汽车车架严重载荷工况下的应力分析

车架的受力十分复杂,首先对某四驱越野车的车架结构进行了分析,对车架模型中不影响整体力学性能的结构部分进行了简化.然后利用Algor软件,建立了该四驱越野车车架的有限元模型.并将紧急制动载荷等效添加到车架模型上.在该车架有限元模型的基础上,对车架在紧急制动和对角线轮上台阶两种严重载荷工况下分别进行了应力分析,得出了整个车架结构的应力分布云图.指出了两种工况下其局部应力较大的部位,并提出了相应的改进措施.     

高原型重型汽车驾驶室的有限元分析

建立了高原型重型汽车驾驶室有限元模型,应用有限元软件对其基本力学性能进行了分析.分析结果确定,驾驶室强度及刚度均可满足使用要求.模态分析发现怠速时易与发动机产生共振,给企业提出了改进建议.     

The stacking sequence optimization of stiffened laminated curved panels with different loading and stiffener spacing

An efficient procedure to obtain the optimal stacking sequence and the minimum weight of stiffened laminated composite curved panels under several loading conditions and stiffener layouts has been developed based on the finite element method and the genetic algorithm that is powerful for the problem with integer variables. Often, designing composite laminates ends up with a stacking sequence optimization that may be formulated as an integer programming problem. This procedure is applied for a problem to find the stacking sequence having a maximum critical buckling load factor and the minimum weight. The object function in this case is the weight of a stiffened laminated composite shell. Three different types of stiffener layouts with different loading conditions are investigated to see how these parameters influence on the stacking sequence optimization of the panel and the stiffeners. It is noticed from the results that the optimal stacking sequence and lay-up angles vary depending on the types of loading and stiffener spacing.