共查询到19条相似文献,搜索用时 218 毫秒
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微分域网格变形方法能够较好的保持网格模型的局部细节特征,但其计算需要耗费较长的时间.结合GPU的高速并行运算性能,设计并实现了一种基于GPU的微分域网格变形算法.通过GPU进行网格的微分坐标求解、线性系统系数矩阵的Cholesky分解、线性系统求解等运算,从而将网格局部细节特征编码和解码过程以及变形结果的绘制完全通过GPU完成.实验结果表明该算法能够有效加速微分域网格变形方法的计算和绘制. 相似文献
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机翼机身对接接头非线性有限元分析 总被引:2,自引:1,他引:1
接头是飞机结构中常见的结构连接形式,也往往是强度破坏或疲劳破坏的部位.有时为了更大的挖掘接头结构的承载能力,甚至还要考虑结构局部进入塑性区应力分布,属于材料非线性和力边界非线性的耦合问题.试图通过直接求解偏微分方程得到接头接触问题的解析解是很难的,甚至可以说是不可能的.基于非线性有限元分析方法,借助大型通用有限元软件MARC的弹塑性接触分析模块,通过不断细化网格的方法来对机翼机身对接接头进行非线性耦合分析.建立了对接接头的弹塑性接触有限元模型,给出了接头的应力分布以及屈服状况.数值模拟结果与实际情况相符,数值模拟结果为机身机翼对接接头的设计提供了重要的数据. 相似文献
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发动机部件强度和刚度评价及疲劳分析 总被引:1,自引:0,他引:1
某汽油机开发阶段须对发动机各主要部件结构强度和刚度做全面评价,并且须考核缸盖缸体的高周疲劳性能.基于STAR-CCM+计算出水套内部气体温度和对流换热系数,将其映射到水套有限元网格表面上作为温度边界条件.得到整个机体的温度场分布以后,在考虑各部件接触非线性的基础上,得到机体各部件的应力和变形等结果并进行评价.在有限元分析结果的基础上考虑材料温度非线性,考察缸体缸盖疲劳安全因数.结果表明,缸盖局部应力偏大,下缸体与油底壳接触面局部间隙过大,缸体缸盖疲劳安全性能满足要求. 相似文献
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有限元仿真方法是结构分析设计中有效仿真方法之一,但计算量巨大.MTALAB软件集科学计算、图像处理于一体,自身又可以作为程序设计语言使用.因此,基于MATLAB开发了石油筛管有限元仿真开发系统SFEM.石油筛管的整体参数与局部细节参数相差30000多倍,普通网格划分方法难以保证精度、计算量巨大、计算速度慢,不能适用于油田现场需要,因此,SFEM引入非自由边界分割法实现了三维网格划分,提高了计算速度和精度,并基于VB平台调用OPENGL实现二维数据的可视化.详细讲述了SFEM的开发过程和关键技术,并举例说明其仿真结果.胜利油田现场数据验证表明,SFEM的仿真结果与实际数据相吻合,SFEM仿真效率高、计算结果可靠. 相似文献
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为了获得更精确的分析结果,在集装箱船舱口角隅应力集中的区域,采用添加过渡单元的方法对原有的粗网格进行细化,然后对局部模型再次进行有限元分析.以此提出一种自动的有限元精细划分的算法.介绍构造过渡单元的方法,并根据计算出的迭代次数,得到细网格后进行分析.最后的结果表明,细化网格后生成的新单元与母单元属性保持一致,对于应力变化剧烈的区域,分析结果好于整体分析的结果. 相似文献
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基于窄带的自适应Level Set方法 总被引:2,自引:0,他引:2
Level Set模型将运动界面表示为高维场函数的零等值面,自然而鲁棒地解决了界面演化中拓扑结构改变的问题,但计算效率不高.文中提出了基于窄带的自适应Level Set方法.自适应方法首先构建粗网格满足界面演化的整体需求,同时估算粗网格点的曲率值,使用快速扩散法聚类高曲率点,通过主元分析估算点集朝向,构建细网格捕捉演化中的细节区域.粗、细网格均为独立的计算单元,定义为存储网格中的有向包围盒.这种数据结构可以有效避免频繁的坐标变换和插值操作,同时保证了数值解的精度.实验结果与误差分析表明,自适应方法能有效减少计算量,达到更好的界面跟踪效果. 相似文献
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许明财 《CAD/CAM与制造业信息化》2005,(2):90-92
结构系统动力分析通常采用总体结构有限元法,但该方法对于复杂大型结构(如飞机、车辆、船舶、高层建筑等整体结构)进行分析存在计算规模大、计算时间长、所用的磁盘空间、计算机系统太庞大等问题,特别是用有限元法进行较高频率振动分析时,要求结构被划分成非常多的单元数,以便获得详细的位移和应力特性.这时结构模型的节点自由度可能达到几十万甚至上百万,直接求解如此庞大的模型是很困难的.即使能够分析,也要耗费大量机时,效率极低. 相似文献
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为确保橡胶密封结构的可靠性,避免因经验设计带来的密封失效,在考虑丁基橡胶材料的超弹性和黏弹性的基础上,采用数值模拟方法分析密封环的形状和密封材料的应力松弛等因素对结构密封性能的影响. 研究结果表明:矩形密封环和梯形密封环的接触应力分布均匀、密封面宽,密封效果优于O形密封环; 但压缩量较大时,矩形密封环外角点处较大的剪切应力会造成密封环局部撕裂,进而影响到整体结构的密封性能. 短时松弛过程中装配预紧力变化的计算结果与试验测试数据吻合较好. 该方法能够预测不同形状密封环在压缩过程中的变形和应力等特征参数,有助于加深了解密封环的密封性能,对同类密封结构设计有一定指导意义. 相似文献
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This study uses an overall knowledge framework concept to carry out engineering knowledge framework categorization for a door-shaped structure. Based on the engineering knowledge and important parameters, combined with agent technology, this study establishes the transverse beam engineering knowledge coding and a case-based similarity method for door-shaped structures. According to the coding model, we establish an associated case-based knowledgebase to carry out data search and inference application so as to shorten the working time. This study only considers the analytic problems of the natural frequency and stress of transverse beams. Looking at these problems, this study establishes different kinds of boundary conditions and load range in sequential order, as well as the related detail parameter coding. Finally, taking a case study which includes the general direct calculation through programs and the detailed dimension trans-coding as an example, this study establishes an automatic mesh model for finite element analysis to solve the analytical problems of vibration and stress. Through the weighting factor, similarity analysis is conducted to search for the similar cases. Furthermore, taking the most similar case located as the foundation, and matching it with regression analysis, this study carries out revised calculation and comparative investigation to rapidly acquire the analytic results. Thus, the proposed method can also shorten the time required for knowledge searching and design analysis by similar structures. 相似文献
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This paper deals with structural shape optimization of shells and folded plates using two-noded Mindlin-Reissner C(0) finite strips. The whole shape optimization process is carried out by integrating finite strip analysis, cubic spline shape definition, automatic mesh generation, sensitivity analysis and mathematical programming methods in an efficient way. Both thickness and shape variables defining the cross-section of the structure are considered. The objective is to minimize the strain energy with a constraint that the total material volume of the structure remains constant. It is observed that minimization of strain energy leads to optimum structures in which the deflections and stress resultants in the members are considerably reduced. This is illustrated using several examples. The relative contributions of the bending, membrane and shear strain energies are also monitored during the whole optimization process. It is found that most optimal shell and folded plate structures are membrane dominant. 相似文献
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民用飞机结构强度设计中的全机精细有限元 分析技术及其应用 总被引:2,自引:0,他引:2
借助大型计算机云计算资源,最大程度地保留结构细节特征进行全机精细有限元建模,并应用于大型民用飞机全机静力试验数值模拟仿真计算。全机精细有限元模型仿真数据与试验数据的对比结果表明:与传统的内力求解等效刚度有限元模型相比,精细模型在结构应力、稳定性和连接强度的计算精度方面具有独特优势。对全机精细有限元模型的建模特点、精度优势和技术难点进行剖析,探讨其在民用飞机结构强度设计中的应用前景。 相似文献
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Clara Cid Bengoa Aitor Baldomir Santiago Hernández Luis Romera 《Structural and Multidisciplinary Optimization》2018,57(3):977-994
Some structures require keeping a specific safety level even if part of their elements have collapsed. The aim of this paper is to obtain the optimum design of these structures when uncertainty in some parameters that affects to the structural response is also considered. A Reliability-Based Design Optimization (RBDO) problem is formulated in order to minimize the mass of the structure fulfilling probabilistic constraints in both intact and damaged configurations. The proposed methodology combines the formulation of multi-model optimization with RBDO techniques programmed in a Matlab code. Two application examples are presented consisting of a two-dimensional truss structure with stress constraints as well as a curved stiffened panel of an aircraft fuselage subjected to buckling constraints. 相似文献
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《Advances in Engineering Software》2002,33(7-10):389-402
In this paper, a mesh generation and mesh refinement procedure for adaptive finite element (FE) analyses of real-life surface structures are proposed. For mesh generation, the advancing front method is employed. FE meshes of curved structures are generated in the respective 2D parametric space of the structure. Thereafter, the 2D mesh is mapped onto the middle surface of the structure. For mesh refinement, two different modes, namely uniform and adaptive mesh refinement, are considered. Remeshing in the context of adaptive mesh refinement is controlled by the spatial distribution of the estimated error of the FE results. Depending on this distribution, remeshing may result in a partial increase and decrease, respectively, of the element size. In contrast to adaptive mesh refinement, uniform mesh refinement is characterized by a reduction of the element size in the entire domain. The different refinement strategies are applied to ultimate load analysis of a retrofitted cooling tower. The influence of the underlying FE discretization on the numerical results is investigated. 相似文献
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塑料检查井埋入地下后会受多种载荷影响,若井壁没有足够的强度和刚度常导致变形,严重时甚至断裂,大大降低检查井工作性能。此外,检查井受到路面车辆等造成的激振作用,若发生共振现象,易造成疲劳损伤。针对此,本文提出6种加筋方案,对埋深5 m的井壁结构进行受力分析,利用ANSYS软件对不同加筋结构进行静力仿真,对满足指标要求的两种网状加筋结构进行6阶模态分析。分析结果表明:加筋方案有利于提高塑料检查井井壁的强度和刚度,且在相同加筋密度下网状加筋优于条状加筋,三角形肋板优于方形肋板,其中三角形网状加筋方案对井壁刚度和强度的提升最明显;三角形网状加筋结构和方形网状加筋结构的固有频率均避开外界激振频率范围。 相似文献
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由于飞机系统结构复杂,功能交联程度高,传统以机内测试(BIT)方法为基础的机载综合诊断方法受到机载测试点设置限制,故障检测、隔离能力无法完全满足部队使用维护需求。近年来,数据驱动方法发展迅速,并被广泛运用到故障诊断中,其中概率神经网络(PNN)凭借其结构简单、计算速度快、运算精度高和分类结果好等优势,非常适合故障诊断与分类问题。但同时,数据驱动方法由于样本不足,工程应用存在困难,不能完全替代传统方法。为提升系统故障检测率、隔离率,降低虚警率,通过应用PNN处理飞机健康状态数据进行故障诊断,并结合BIT中的诊断信息,利用二者间的互补性提出了一种混合增强飞机系统故障诊断方法。详细介绍了该融合方法的基本原理、融合层次、融合规则等。最后,通过某型号飞机分系统诊断实例表明,该方法检测、隔离能力有显著提升,能够满足功能交联条件下飞机故障诊断需求。 相似文献
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Christian Van der Velden Cees Bil Xinghuo Yu Adrian Smith 《Innovations in Systems and Software Engineering》2007,3(2):117-128
This paper discusses the development of an intelligent routing system for automating design of electrical wiring harnesses
and pipes in aircraft. The system employs knowledge based engineering (KBE) methods and technologies for capturing and implementing
rules and engineering knowledge relating to the routing process. The system reads a mesh of three dimensional structure and
obstacles falling within a given search space and connects source and target terminals satisfying a knowledge base of design
rules and best practices. Routed paths are output as computer aided design (CAD) readable geometry, and a finite element (FE)
mesh consisting of geometry, routed paths and a knowledge layer providing detail of the rules and knowledge implemented in
the process. Use of this intelligent routing system provides structure to the routing design process and has potential to
deliver significant savings in time and cost. 相似文献