Three-dimensional localization of thin-walled sheet metal parts for robotic assembly

2002 ◽  
Vol 19 (5) ◽  
pp. 207-217 ◽  
Author(s):  
Edward J. Park ◽  
James K. Mills
Keyword(s):  
Sheet Metal ◽  
Three Dimensional ◽  
Robotic Assembly ◽  
Metal Parts ◽  
Sheet Metal Parts ◽  
Thin Walled

Prediction of Residual Stress on Cold-Formed Curvature Plates by Elastoplastic Material Model

2020 ◽  
pp. 1-15
Author(s):  
Yue Lin ◽  
Wei Shen ◽  
Lifei Song ◽  
Enqian Liu
Keyword(s):  
Residual Stress ◽  
Sheet Metal ◽  
Production Efficiency ◽  
Three Dimensional ◽  
Elastoplastic Material ◽  
Curved Surfaces ◽  
Automatic Production ◽  
Cold Forming ◽  
Metal Parts ◽  
Sheet Metal Parts

To meet the demand of automatic production, the multisquare punch forming has been improved to process complex curved plates. However, the improved forming equipment improves the processing quality to the maximum extent, and springback and residual stresses are inevitable phenomena in the cold bending process. Residual stress is an important factor that causes fatigue crack and stress corrosion crack. And the residual stress in machining will seriously affect the fatigue life of cold-pressed parts. Therefore, it is necessary to quantitatively and qualitatively analyze the residual stress caused by the cold forming equipment. Through theoretical derivation and finite element simulation methods, the residual stress distribution for thick plates in the cold forming process was analyzed and compared in this article. Meanwhile, the variation law of residual stress peak with thickness and forming radius was further discussed. The results show that the residual stress distributions obtained by the two theoretical models are in good agreement with the numerical results. The maximum error of peak residual stress is about 10%, which verifies the reliability of theoretical formulas. 1. Introduction A large number of complex curved sheet metal parts are used in aerospace, marine structure, automobile, and other manufacturing industries, which makes the processing and forming of complex curved sheet metal parts attract much attention. In the process of ship construction, the forming and processing of hull plates is an important part of the low intelligence, time-consuming, and serious constraint on shipbuilding automation. Strictly speaking, most of the parts in the hull plate are three-dimensional curved surfaces, most of which are composed of complex undevelopable spatial curved surfaces. It is a very difficult and urgent key technology to process a ship's steel plate into complex three-dimensional curved surface shapes. such as saddle shape or sailed shape (see Fig. 1A), to create a streamlined outer body of the ship. For many years, bending of plates with complex curvatures has been carried out by manual operation, i.e., the combination of heat line forming and rolling bending (see Fig. 1B). However, the production efficiency of the thermoforming process is relatively low, and environmental pollution is relatively serious with bad working conditions and high labor intensity. Moreover, the forming quality depends more on the experience of technicians, and quality cannot be guaranteed. With the increasing demand for automation, the multipoint forming equipment was developed and used for stamping and forming of curved plates.

Forming Stability Analysis of Surface Flexible Rolling

2013 ◽  
Vol 798-799 ◽  
pp. 267-271
Author(s):  
Ren Jun Li ◽  
Ming Zhe Li ◽  
Zhong Yi Cai
Keyword(s):  
Numerical Simulation ◽  
Stability Analysis ◽  
Sheet Metal ◽  
Three Dimensional ◽  
Continuous Manufacturing ◽  
Forming Process ◽  
Metal Parts ◽  
Sheet Metal Parts ◽  
Flexible Rolling ◽  
Simulation Results

Surface flexible rolling method, using two integral working rolls as the forming tool, can achieve fast, flexible and continuous manufacturing of three-dimensional sheet metal parts. This paper introduces the basic principle of surface flexible rolling and discusses the numerical simulation results when the working rolls are bended as circular arcs. The stability indicates the forming effect to some extent and the flow type of the metal can be deduced from stability analysis. To integrate and analyze the simulation results by means of reverse engineering. The analysis results show that the forming process is stable and the effect of surface flexible rolling is fine. It also indicates that inhomogeneous deformation and accumulation occurs during the process. The numerical simulation and experimental results demonstrate that the surface flexible rolling is a feasible and effective way to form three-dimensional sheet metal parts.

On the Topology of Sheet Metal Parts

1998 ◽  
Vol 120 (1) ◽  
pp. 10-16 ◽  
Author(s):  
H. Lipson ◽  
M. Shpitalni
Keyword(s):  
Sheet Metal ◽  
Conceptual Design ◽  
Topological Invariant ◽  
Manufacturing Processes ◽  
Qualitative Model ◽  
Topological Properties ◽  
Metal Parts ◽  
Sheet Metal Parts ◽  
Thin Walled ◽  
Euler Operators

This paper analyzes the topological properties of sheet metal parts represented schematically (zero thickness, zero bend radii). Although such parts are usually non-manifold objects, the paper establishes a general topological invariant f = s + b + e + w − v − gnm + m regarding the number of facets, components, bends, free edges, welds, vertices holes and volumes, respectively. Corresponding Euler operators are derived, providing a basis for a modeling system for sheet metal parts. With this invariant, it is possible to reason about manufacturing processes, such as number of components and arrangement of bend lines and weld lines, using only a single qualitative model of the product. This capability is particularly useful in the preliminary stage of conceptual design. A corresponding topological invariant v − e + f = s + m − gnm is also proposed for general sheet models and thin walled objects.

Development of Flexible Rolling Device for 3D Plate

2012 ◽  
Vol 271-272 ◽  
pp. 852-857
Author(s):  
Ren Jun Li ◽  
Ming Zhe Li ◽  
Ning Jia Qiu
Keyword(s):  
Research And Development ◽  
Sheet Metal ◽  
Three Dimensional ◽  
Metal Parts ◽  
Sheet Metal Parts ◽  
Flexible Rolling ◽  
Design Scheme ◽  
Working Principle ◽  
Conventional Rolling ◽  
Dimensional Surface

To effectively form three-dimensional sheet metal parts with various curvatures produced in small quantities, flexible rolling forming, a new flexible forming method is being developed. Firstly, concept of the flexible rolling forming is introduced and its characteristics and working principle are analyzed by the combination of conventional rolling and multi-point forming. Secondly, the equipment design scheme of flexible rolling forming is put forward and the relevant device is developed. Thirdly, the feasibility and practicality of flexible rolling forming are verified by rolling several typical three-dimensional surface parts such as spherical and saddle surface parts by self-developed device. Finally, verifies the reasonableness of the device and at the same time possesses the important guiding significance to the research and development of practical flexible rolling forming equipment.

Surface flexible rolling for three-dimensional sheet metal parts

2014 ◽  
Vol 214 (2) ◽  
pp. 380-389 ◽  
Author(s):  
Ren-Jun Li ◽  
Ming-Zhe Li ◽  
Ning-Jia Qiu ◽  
Zhong-Yi Cai
Keyword(s):  
Sheet Metal ◽  
Three Dimensional ◽  
Metal Parts ◽  
Sheet Metal Parts ◽  
Flexible Rolling

Modeling and predicting of aeronautical thin-walled sheet metal parts riveting deformation

2016 ◽  
Vol 36 (3) ◽  
pp. 295-307 ◽  
Author(s):  
Zhengping Chang ◽  
Zhongqi Wang ◽  
Bo Jiang ◽  
Jinming Zhang ◽  
Feiyan Guo ◽  
...  
Keyword(s):  
Sheet Metal ◽  
Element Model ◽  
Local Deformation ◽  
Calculation Model ◽  
Content Type ◽  
Metal Parts ◽  
Sheet Metal Parts ◽  
Thin Walled ◽  
The Impact ◽  
Successive Calculation

Purpose Riveting deformation is inevitable because of local relatively large material flows and typical compliant parts assembly, which affect the final product dimensional quality and fatigue durability. However, traditional approaches are concentrated on elastic assembly variation simulation and do not consider the impact of local plastic deformation. This paper aims to present a successive calculation model to study the riveting deformation where local deformation is taken into consideration. Design/methodology/approach Based on the material constitutive model and friction coefficient obtained by experiments, an accurate three-dimensional finite element model was built primarily using ABAQUS and was verified by experiments. A successive calculation model of predicting riveting deformation was implemented by the Python and Matlab and was solved by the ABAQUS. Finally, three configuration experiments were conducted to evaluate the effectiveness of the model. Findings The model predicting results, obtained from two simple coupons and a wing panel, showed that it was a good compliant with the experimental results, and the riveting sequences had a significant effect on the distribution and magnitude of deformation. Practical implications The proposed model of predicting the deformation from riveting process was available in the early design stages, and some efficient suggestions for controlling deformation could be obtained. Originality/value A new predicting model of thin-walled sheet metal parts riveting deformation was presented to help the engineers to predict and control the assembly deformation more exactly.

A CAD-Driven Flexible Forming System for Three-Dimensional Sheet Metal Parts

1993 ◽  
Author(s):  
David E. Hardt ◽  
Mary C. Boyce ◽  
Karl B. Ousterhout ◽  
Apostolos Karafillis ◽  
Gary M. Eigen
Keyword(s):  
Sheet Metal ◽  
Three Dimensional ◽  
Flexible Forming ◽  
Metal Parts ◽  
Sheet Metal Parts

Study on the Inspection & Planning System for Sheet Metal Parts Based on its Three Dimensional Model

2013 ◽  
Vol 446-447 ◽  
pp. 585-589
Author(s):  
Lei Hua ◽  
Dong Wang ◽  
Bo Hao ◽  
Li He
Keyword(s):  
Sheet Metal ◽  
High Efficiency ◽  
Three Dimensional ◽  
Planning System ◽  
Inspection Planning ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Inspection Method ◽  
Metal Parts ◽  
Sheet Metal Parts

Aiming at the short comings and limitations of traditional inspection method of sheet metal parts, the inspection solution based on the three dimensional model of sheet metal parts was described in this paper. According to the shape, size, accuracy requirements and so on, the system can give different inspection method. The inspection result will be achieved and the system can judge if the measured sheet metal part is qualified. The characteristics of this system are high accuracy, environmental protection and high efficiency.

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