Efficient Variation Simulation of Spot-Welded Assemblies

Variation simulation for assembled products is one important activity during product development. Variation simulation enables the designer to understand not only the features of the nominal product but also how uncertainty will affect production, functions and the aesthetic properties of the final product. For parts that are able to deform during assembly, compliant variation simulation is needed for accurate prediction. For this the Finite Element Method (FEM) is used. Despite many effective efforts to decrease simulation times for compliant variation simulation, simulation time is still considered an obstacle for full scale industrial use. In this paper, a new formulation for compliant variation simulation of assemblies that are joined in sequential spot-welding will be presented. In this formulation the deformation in the intermediate springback steps during the simulation of a spot-weld sequence do not have to be calculated. This is one of the most time consuming steps in sequential spot-welding simulation. Furthermore, avoiding the intermediate springback calculation will reduce the size of memory of the computer models since the number of sensitivity matrices is reduced. The formulation is implemented using the latest developments in compliant variation simulation, that is the Method of Influence Coefficients (MIC) where the Sherman-Morrison-Woodbury-formula is used to update the resulting sensitivity matrices and the contact- and weld forces are solved using a Quadratic Programme (QP). Industrial cases are used to demonstrate the reduced simulation time. It is believed that the reduction in simulation times will have future implications on sequence optimization for spot-welded assemblies.

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Resistance spot welding. Destructive tests of welds. Method for the fatigue testing of spot welded joints

10.3403/02852592 ◽

2003 ◽

Cited By ~ 1

Keyword(s):

Welded Joints ◽

Resistance Spot Welding ◽

Spot Welding ◽

Fatigue Testing ◽

Resistance Spot ◽

Spot Welded

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Nonlinear Material Model in Part Variation Simulations of Sheet Metals

Journal of Computing and Information Science in Engineering ◽

10.1115/1.4042539 ◽

2019 ◽

Vol 19 (2) ◽

Cited By ~ 2

Author(s):

Soner Camuz ◽

Samuel Lorin ◽

Kristina Wärmefjord ◽

Rikard Söderberg

Keyword(s):

Material Model ◽

Nonlinear Material ◽

Isotropic Hardening ◽

Elastoplastic Material ◽

Processing Unit ◽

Central Processing ◽

Physical Experiments ◽

Linear Relationships ◽

Influence Coefficients ◽

Variation Simulation

Current methodologies for variation simulation of compliant sheet metal assemblies and parts are simplified by assuming linear relationships. From the observed physical experiments, it is evident that plastic strains are a source of error that is not captured in the conventional variational simulation methods. This paper presents an adaptation toward an elastoplastic material model with isotropic hardening in the method of influence coefficients (MIC) methodology for variation simulations. The results are presented in two case studies using a benchmark case involving a two-dimensional (2D) quarter symmetric plate with a centered hole, subjected to both uniaxial and biaxial displacement. The adaptation shows a great reduction in central processing unit time with limited effect on the accuracy of the results compared to direct Monte Carlo simulations.

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Parametric optimization of resistance spot welding for multi spot welded lap shear specimen to predict weld strength

Materials Today Proceedings ◽

10.1016/j.matpr.2019.07.756 ◽

2019 ◽

Vol 19 ◽

pp. 700-707

Author(s):

P.A. Dhawale ◽

B.P. Ronge

Keyword(s):

Resistance Spot Welding ◽

Spot Welding ◽

Parametric Optimization ◽

Weld Strength ◽

Resistance Spot ◽

Shear Specimen ◽

Lap Shear ◽

Spot Welded

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A Maxwell's Second Equation Approach to the Finite Element Method Applied to Magnetic Field Determination

International Journal of Electrical Engineering Education ◽

10.1177/002072098702400313 ◽

1987 ◽

Vol 24 (3) ◽

pp. 259-272 ◽

Cited By ~ 5

Author(s):

José Roberto Cardoso

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Undergraduate Students ◽

Engineering Students ◽

Numerical Procedure ◽

The Finite Element Method ◽

Cad Cam ◽

New Formulation ◽

The Galerkin Method ◽

Element Method

The burst of modern computing systems like CAD/CAM has given rise to the use of the finite element method (FEM), which is, at present, the most used numerical procedure in the determination of fields in continuous media. Undergraduate students find difficulty in understanding the usual way of demonstrating FEM by variational analysis or the Galerkin method. This paper introduces a new formulation of FEM, based on a direct application of Maxwell's second equation, which can be easily understood by undergraduate engineering students.

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Non-Rigid Variation Simulation Using the Sherman-Morrison-Woodbury Formulas

Volume 2: Advanced Manufacturing ◽

10.1115/imece2017-71456 ◽

2017 ◽

Cited By ~ 3

Author(s):

Samuel Lorin ◽

Björn Lindau ◽

Lars Lindkvist ◽

Rikard Söderberg

Keyword(s):

Product Development ◽

Manufacturing Process ◽

Computation Time ◽

Statistical Distribution ◽

Influence Coefficient ◽

Substantial Saving ◽

Variation Simulation ◽

Important Activity

Variation simulation is one important activity during early product development. It is used to simulate the statistical distribution of assemblies or sub assemblies in intended manufacturing process to assure that assembly, function and aesthetical properties comply with the requirements set. In non-rigid variation simulation, components or sub assemblies can deform during assembly. To simulate non-rigid variation the Method of Influence Coefficient (MIC) is typically used. Solving the necessary sensitivity matrices used by MIC is time consuming. In this article we will apply the Sherman-Morrison and Woodbury formula (SMW) for updating the sensitivity response in the different assembly steps. It is shown that SMW can lead to substantial saving in computation time, when compared to the standard MIC.

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Hot Rolling Simulation System for Steel Based on Advanced Meshless Solution

Metals ◽

10.3390/met9070788 ◽

2019 ◽

Vol 9 (7) ◽

pp. 788 ◽

Cited By ~ 8

Author(s):

Umut Hanoglu ◽

Božidar Šarler

Keyword(s):

Hot Rolling ◽

Rolling Mill ◽

Simulation System ◽

The Novel ◽

The Finite Element Method ◽

Model Assumption ◽

Industrial Use ◽

Simulation Results ◽

User Friendly ◽

Net Framework

In this work, a rolling simulation system for the hot rolling of steel is elaborated. The system is capable of simulating rolling of slabs and blooms, as well as round or square billets, in different symmetric or asymmetric forms in continuous, reversing, or combined rolling. Groove geometries are user-defined and an arbitrary number of rolling stands and distances between them may be used. A slice model assumption is considered, which allows the problem to be efficiently coped with. The related large-deformation thermomechanical problem is solved by the novel meshless Local Radial Basis Function Collocation Method. A compression test is used to compare the simulation results with the Finite Element Method. A user-friendly rolling simulation application has been created for the industrial use based on C# and .NET framework. Results of the simulation, directly taken from the system, are shown for each type of the rolling mill configurations.

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Microstructure and Fracture Behavior of Refill Friction Stir Spot Welded Joints of AA2024 Using a Novel Refill Technique

Metals ◽

10.3390/met9030286 ◽

2019 ◽

Vol 9 (3) ◽

pp. 286 ◽

Cited By ~ 1

Author(s):

Lipeng Deng ◽

Shuhan Li ◽

Liming Ke ◽

Jinhe Liu ◽

Jidong Kang

Keyword(s):

Spot Welding ◽

Fracture Behavior ◽

Shear Fracture ◽

Load Capacity ◽

Maximum Load ◽

Fusion Welding ◽

Tensile Shear ◽

Friction Stir ◽

Corona Ring ◽

Spot Welded

Keyhole at the end of a conventional friction stir welded (FSW) joint is one of the major concerns in certain applications. To address this issue, a novel keyhole refilling technique was developed for conventional friction stir spot welding (FSSW) using resistance spot welding (RSW). A three-phase secondary rectifier resistance welder was adapted for the refill of the keyhole in the 1.5 mm + 1.5 mm friction stir spot welded 2024-T4 aluminum alloy joint. The microstructure and tensile shear fracture behavior were compared for both the unfilled and refilled specimens. The results show that the plug and keyhole are dominated by solid state welding with some localized zones by fusion welding. The refill process significantly improved the maximum load capacity in tensile shear testing as the corona ring is enlarged leading to a larger bonding area. Moreover, the tensile shear fracture occurs in the refilled FSSW specimens at the corona bonding zone, while the fracture occurs at the hook zone in the unfilled keyhole.

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Numerical Modeling of Optical Fibers Using the Finite Element Method and an Exact Non-reflecting Boundary Condition

Computational Methods in Applied Mathematics ◽

10.1515/cmam-2017-0049 ◽

2018 ◽

Vol 18 (4) ◽

pp. 581-601

Author(s):

Rafail Z. Dautov ◽

Evgenii M. Karchevskii

Keyword(s):

Finite Element Method ◽

Boundary Condition ◽

Finite Element ◽

Numerical Modeling ◽

Optical Fibers ◽

Original Problem ◽

Approximate Solutions ◽

The Finite Element Method ◽

New Formulation ◽

Adjoint Operators

AbstractThe original problem for eigenwaves of weakly guiding optical fibers formulated on the plane is reduced to a convenient for numerical solution linear parametric eigenvalue problem posed in a disk. The study of the solvability of this problem is based on the spectral theory of compact self-adjoint operators. Properties of dispersion curves are investigated for the new formulation of the problem. An efficient numerical method based on FEM approximations is developed. Error estimates for approximate solutions are derived. The rate of convergence for the presented algorithm is investigated numerically.

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