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面向ASP与DFA集成系统的装配模型技术 总被引:5,自引:0,他引:5
针对并行工程中的产品装配设计与优化分析 ,提出了一种装配顺序规划与为装配而设计相集成的产品装配分析系统。重点分析研究了集成系统中的产品装配建模方法。首先对现有的各种典型的装配模型技术进行分析比较 ;其次 ,根据 ASP与DFA集成系统的需求 ,设计出了一种包含装配草图、装配关联图信息、装配结构树图、零件设计参数和连接参数等信息的装配模型结构。并结合实例分析了该装配模型的计算机实现方法 相似文献
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车身柔性虚拟装配偏差模拟分析 总被引:1,自引:1,他引:0
在轿车样车试制阶段,为了减少车身尺寸功能评估周期和降低评估成本,引入了车身的虚拟装配.针对功能评估中虚拟装配关键技术,包括装配过程夹具偏差、焊接处理及多工位装配等提出解决方案,实现了在考虑制造偏差、夹具偏差、连接偏差和多工位装配基础上的车身虚拟装配.通过案例论证了提出的虚拟装配方法的可行性.结果表明,该模型的准确度较高,适用于柔性薄板零件的装配偏差分析. 相似文献
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零件装配连接关系是多零件装配体(如汽车车身)在计算机辅助装配规划中装配模型建立的关键内容,提出了一种利用中性产品模型数据交换标准生成装配连接关系的方法。该方法首先利用产品模型数据交换标准文件的低层几何信息构建零件的包容盒,再在建立零件包容盒拓扑关系的基础上,通过判别与零件的连接映射关系,推导出零件的连接关系信息。最后,通过实例验证了所提出方法的准确性和有效性。 相似文献
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三维装配尺寸链的自动生成 总被引:17,自引:2,他引:15
提出了一种基于CAD模型的三维装配尺寸链自动生成方法。该方法从定义装配性能特征入手,首先对CAD装配模型进行深层次的解析及预处理,以获取隐含在模型内部的公差分析所需信息。然后利用图论理论,通过构建特征-尺寸邻接矩阵、特征-装配约束关系邻接矩阵、装配关系传递图等,将装配体中参与装配的零件和特征以及其之间的装配约束关系、尺寸及形状等信息的传递过程以图的形式进行表达。最后将三维尺寸链分为显式和隐式两类,对于显式尺寸链,由装配关系传递图搜索连通通路可直接获取尺寸链图和方程:对于隐式尺寸链,提出了尺寸方向差异度的概念、封闭环方向优先的搜索策略以及构建过渡尺寸链的方法,最终可获取尺寸链图和方程。该方法已在自主开发的三维装配尺寸链自动生成系统中得到了验证。 相似文献
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基于适应性装配特征的自动装配技术研究 总被引:2,自引:0,他引:2
装配设计是现代CAD技术中的一个重要组成部分,但其中对零部件自动装配的研究还相对薄弱。笔者在研究参数化设计和装配建模的基础上,提出了基于适应性装配特征的零部件自动装配方法,根据适应性装配特征来确定零部件间装配关系和装配对象的主参数,以便适应调整装配对象姿态、完成自动装配、提高装配设计的速度和效率。根据以上研究开发的基于CATIA平台的导管焊接夹具自动装配模块,验证了该方法的有效性和实用性。 相似文献
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基于语义推理的产品装配设计技术 总被引:1,自引:0,他引:1
为保证产品具有良好的结构设计和零件可装配性,研究了装配语义模型,详细讨论了设计尺寸约束和装配几何约束的符号化表达方法,并给出了书写规则。在此基础上建立了装配语义图,通过节点描述零件属性信息,通过有向边描述装配语义信息。介绍了基于装配语义的产品装配设计工作流程,重点阐述了零件设计尺寸约束、装配规划信息和装配操作序列的推理过程。给出了语义修改和语义变动两种情况下装配语义图的维护机制。应用实例表明,该模型可以有效地支持产品的协同装配设计。 相似文献
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分布环境下面向装配的产品协同设计集成平台 总被引:2,自引:0,他引:2
为提高异地设计时产品的可装配性设计质量,提出了分布环境下面向装配的产品协同设计方法,从零件设计、产品结构预装配和产品过程预装配3个方面论述了可装配性设计内容,建立并实现了支持网络环境下面向装配的产品协同设计集成平台,详细描述了平台的功能模块,并通过涡轮膨胀机实例说明了异地人员间利用该平台实施面向装配的协同设计过程。 相似文献
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A systematic method of adaptive joint design considering different assembly sequence in sheet metal product 总被引:1,自引:1,他引:0
Jun Cao Xinmin Lai Sun Jin Zhongqin Lin 《The International Journal of Advanced Manufacturing Technology》2007,34(5-6):457-463
In sheet metal assembly, not only the component variations and tool errors, but also the component structure (joint type)
and assembly process (assembly sequence) affect the final dimensional quality. In this paper, a systematic method for adaptive
joint design considering different assembly sequence is proposed to meet the in-process dimensional adjustability of KCs (key
characteristics). First, the adaptive characteristic of the sheet metal joint is depicted. Then, the mathematical model in
order for concurrently optimizing both joint type and different assembly sequence is presented. How to evaluate the combination
of joint type and assembly sequence is carried out according to two conditions: (1) for single KC, and (2) for multiple KCs.
The KC confliction is considered to ensure the important KCs. Genetic algorithm is used to resolve the optimization of joint
design. An example is chosen to demonstrate our method finally, and various joint designs are acquired according to different
assembly sequences by this means. The proposed methods make it possible for us to improve the dimensional quality of product
in the design stage. 相似文献
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Y. Gene Liao 《The International Journal of Advanced Manufacturing Technology》2005,26(5-6):512-516
In the sheet metal assembly process, welding operations join two or more sheet metal parts together. Since sheet metals are subject to dimensional variation resulting from manufacturing randomness, a gap may be generated at each weld pair prior to welding. These gaps are forced to close during the welding operation and accordingly undesirable structural deformation results. Optimizing the welding pattern (the number and locations of weld pairs) in the assembly process was proven to improve significantly the quality of the final assembly. This paper presents a genetic-algorithm-based optimization method to search automatically for the optimal weld pattern so that assembly deformation is minimized. The application result for a real industrial part demonstrated that the proposed algorithm effectively achieved the objective. 相似文献
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Xiaoyun Liao G. Gary Wang 《The International Journal of Advanced Manufacturing Technology》2008,36(3-4):386-394
This paper presents an optimization methodology for non-rigid sheet metal assembly variation by considering part variation,
fixture variation, fixture layout, and joint positions, as well as the assembly spring back. The proposed algorithm integrates
the finite element analysis (FEA) with a powerful global optimization algorithm, called the mode-pursuing sampling (MPS) method
to simultaneously search for the optimal fixture and joint positions in order to minimize the assembly variation. An example
application study is presented to demonstrate the optimization procedure and its effectiveness. 相似文献
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Bing Li Hui Tang Xiaoping Yang Hao Wang 《The International Journal of Advanced Manufacturing Technology》2007,32(7-8):690-697
Fixturing plays an important role in enhancing weld quality of the sheet metal assembly process. However, traditional experience-based
fixturing schemes and purely optimal fixturing schemes are often sensitive to location fluctuation of the designed locators.
In this paper a mathematical representation of deterministic locating and total fixturing for a flexible workpiece is developed
first, then a virtual beam model is proposed to evaluate the degree of flexibility of the locating points. A quality design
model of fixture planning for sheet metal assembly with resistance spot welding is then developed; both the performance expectation
and the variance are considered in the formulation of the objective function; a prescribed factor is used to weight the two
objectives. The finite element model based on ANSYS software is set up with a spot weld feature employed and genetic algorithm
is used in the optimization process. A simple example and an industrial case illustrate the feasibility of the developed model.
This work provides a basis for improving the quality of sheet metal assembly in the design phase. 相似文献
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Li Yubing Chen Guanlong Zheng Cheng Lai Xinmin 《The International Journal of Advanced Manufacturing Technology》2008,37(1-2):178-190
In this paper, an intelligent heuristic optimization algorithm in active variation compensation is proposed to improve the
dimension accuracy in the assembly of a vehicle body by finding the optimal configuration of joint types and the corresponding
assembly sequence to compensate variation accumulation in the conceptual assembly process. The authors develop and apply the
algorithm to predict variation accumulation and then develop compensating assembly schemes to accomplish optimal joint configuration
and assembly sequence compensating for the unnecessary or surplus variation. The essence of the active variation compensation
algorithm means measuring and correcting assembling variations during the assembly conceptual process. The paper employs the
design of experiment (DOE) approach to verify the heuristic optimization method in the simple application case. 相似文献
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Y. Gene Liao 《The International Journal of Advanced Manufacturing Technology》2005,26(5):512-516
In the sheet metal assembly process, welding operations join two or more sheet metal parts together. Since sheet metals are subject to dimensional variation resulting from manufacturing randomness, a gap may be generated at each weld pair prior to welding. These gaps are forced to close during the welding operation and accordingly undesirable structural deformation results. Optimizing the welding pattern (the number and locations of weld pairs) in the assembly process was proven to improve significantly the quality of the final assembly. This paper presents a genetic-algorithm-based optimization method to search automatically for the optimal weld pattern so that assembly deformation is minimized. The application result for a real industrial part demonstrated that the proposed algorithm effectively achieved the objective. 相似文献
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Chen Shaoyun Lin Zhongqin Zhang Yizhu Li Yongbing 《The International Journal of Advanced Manufacturing Technology》2006,29(5):446-452
The characteristics of joints between parts are one of the most critical issues in variation simulation analysis. This paper
presents a parametric study of the dimensional variation characteristics of butt joints and slip joints. These two basic joints
encompass the whole domain of joints used in sheet metal assemblies for structural extension. A geometrical model was proposed
for predicting the assembly variation in order to take into consideration the possibility of part deformation and tool variation.
Butt joints act like rigid bodies in the normal direction. For slip joints, the sensitivity coefficient in the slip direction
is a function of tooling variations. The variation from individual part and tooling can be eliminated or substantially reduced
if the product structure and assembly process is properly designed. A simple four-part assembly example shows the structure
and assembly process. This result provides improved understanding of sheet metal assembly processes and provides a new idea
for adaptive product and process design. 相似文献
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Shaoyun Chen Zhongqin Lin Yizhu Zhang Yoongbing Li 《The International Journal of Advanced Manufacturing Technology》2006,29(5-6):446-452
The characteristics of joints between parts are one of the most critical issues in variation simulation analysis. This paper
presents a parametric study of the dimensional variation characteristics of butt joints and slip joints. These two basic joints
encompass the whole domain of joints used in sheet metal assemblies for structural extension. A geometrical model was proposed
for predicting the assembly variation in order to take into consideration the possibility of part deformation and tool variation.
Butt joints act like rigid bodies in the normal direction. For slip joints, the sensitivity coefficient in the slip direction
is a function of tooling variations. The variation from individual part and tooling can be eliminated or substantially reduced
if the product structure and assembly process is properly designed. A simple four-part assembly example shows the structure
and assembly process. This result provides improved understanding of sheet metal assembly processes and provides a new idea
for adaptive product and process design. 相似文献