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.

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.

Sheet Modeling and Thickening Operations Based on Non-Manifold Boundary Representations

2001 ◽  
Author(s):  
Sang Hun Lee ◽  
Hyun-Soo Kim
Keyword(s):  
Boundary Representation ◽  
Metal Parts ◽  
Sheet Metal Parts ◽  
Solid Models ◽  
Boundary Representations ◽  
Thin Walled ◽  
Topological Framework ◽  
Manifold Models ◽  
Definition Of ◽  
Euler Operators

Abstract This paper describes sheet modeling and thickening operations based on a non-manifold topological representation for efficient solid modeling of thin-walled plastic or sheet metal parts. Since the existing methods have adopted boundary representations for solid models, it is difficult to represent the exact adjacency relations between topological entities in a sheet model, and to describe a mixture of wireframe and sheet objects that appear in the intermediate steps of sheet modeling operations. Accordingly, it is difficult to devise and implement the algorithms for sheet modeling and thickening operations. To solve these problems, we introduce a non-manifold boundary representation as a topological framework and propose a sheet thickening algorithm by presenting variations to a general non-manifold offset algorithm that is based on the mathematical definition of offsets. In addition, to facilitate sheet modeling operations, not only a set of generalized Euler operators for non-manifold models are provided, but also sheet modeling capabilities, including adding, bending, and punching functions with two-dimensional curve editors.

Experimental and Numerical Analysis of Blanking for Thin Sheet Metal Parts

2001 ◽  
Vol 4 (3-4) ◽  
pp. 319-333
Author(s):  
Vincent Lemiale ◽  
Philippe Picart ◽  
Sébastien Meunier
Keyword(s):  
Numerical Analysis ◽  
Sheet Metal ◽  
Thin Sheet ◽  
Metal Parts ◽  
Sheet Metal Parts ◽  
Thin Sheet Metal
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