Numerical and experimental analysis on cold-forming and spring-back of hull plate

2018 ◽  
Vol 233 (3) ◽  
pp. 561-569 ◽  
Author(s):  
Wei Shen ◽  
Renjun Yan ◽  
Shuangying Li
Keyword(s):  
Three Dimensional ◽  
Dimensional Accuracy ◽  
Ship Hull ◽  
Laser Forming ◽  
Successive Approximation Method ◽  
Spring Back ◽  
Forming Process ◽  
Cold Forming ◽  
Thick Plates ◽  
Forming Mechanism

Ship hull structures are fabricated by curved thick plates before they are welded together. There are traditional methods such as, line heating and laser-forming methods for plate bending. However, it is recognized that the hot-forming technology causes a series of troubles on doubly or multiple curved plates. Multi-point forming mechanism with square press heads is a new forming process for three-dimensional ship hull plate. Cold-forming has a high dimensional accuracy but results in spring-back. The spring-back process of curved thick plates in the finite element method is analyzed and the predicted results are compared with the test results in the present paper. To ensure the forming precision, the successive approximation method is also developed and verified to control the spring-back.

Spring-back analysis in the cold-forming process of ship hull plates

2018 ◽  
Vol 96 (5-8) ◽  
pp. 2341-2354 ◽  
Author(s):  
Wei Shen ◽  
Renjun Yan ◽  
Shuangyin Li ◽  
Lin Xu
Keyword(s):  
Back Analysis ◽  
Ship Hull ◽  
Spring Back ◽  
Forming Process ◽  
Cold Forming

Nonlinear Finite Element Analysis of Spring-Back Characteristics in the Cold-Forming Process of Three-Dimensionally Curved Thick Metal Plates

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Jeom Kee Paik ◽  
Jeong Hwan Kim ◽  
Bong Ju Kim ◽  
Chang Hyo Tak
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Steel Plates ◽  
Research Centre ◽  
Spring Back ◽  
Forming Process ◽  
Element Analysis ◽  
Cold Forming ◽  
Metal Plates ◽  
National University

The present paper is part of the study to develop the advanced computer aided manufacture (CAM) system called the changeable die system (CDS) that applies the cold-forming technique to produce curved thick metal plates with complex, three-dimensional geometry [Paik et al., 2009, “Development of the Changeable Die System for the Cold-Forming of Three-Dimensionally Curved Metal Plates,” The Lloyd's Register Educational Trust Research Centre of Excellence, Pusan National University, Korea]. This paper focuses on the procedure of predicting the spring-back characteristics using elastic-plastic large deflection finite element method, which is a key technical element within the framework of the CDS process. The validity of the procedure is confirmed by comparison with experimental results obtained by the CDS machine in the cold-forming process of curved steel plates.

Comparison of Material Behavior and Economic Effects of Cold and High Temperature Forming Technologies Applied to High-Strength Steels

2005 ◽  
Vol 6-8 ◽  
pp. 101-108 ◽  
Author(s):  
Reimund Neugebauer ◽  
Angela Göschel ◽  
Andreas Sterzing ◽  
Petr Kurka ◽  
Michael Seifert
Keyword(s):  
Elevated Temperatures ◽  
High Strength Steels ◽  
Dimensional Accuracy ◽  
High Strength ◽  
Economic Effects ◽  
Material Behavior ◽  
Spring Back ◽  
Forming Process ◽  
Cold Forming ◽  
Forming Tools

The focus of forming high-strength steel at elevated temperature is to improve its forming properties like elongation and to reduce the power requirements during the forming process in opposite to cold forming. Because of the undefined and large spring-back effects parts made by cold forming are not able to achieve the demanded dimensional accuracy, which is necessary for laser welding operations in car body assembly. The reduction of the spring-back behavior is another advantage of the temperature controlled forming technology. On the other side the forming at elevated temperatures requires increased costs for forming tools and tempering equipment. For a fundamental evaluation of this technology, expenditures for the complete process chain have to be considered.

Analysis of Spring-Back Behavior in the Cold-Forming Process of Three-Dimensionally Curved Metal Plates

2010 ◽  
Author(s):  
Jeom Kee Paik ◽  
Jeong Hwan Kim ◽  
Bong Ju Kim ◽  
Chang Hyo Tak
Keyword(s):  
Three Dimensional ◽  
Nonlinear Finite Element ◽  
Steel Plates ◽  
Nonlinear Finite Element Method ◽  
Spring Back ◽  
Forming Process ◽  
Cold Forming ◽  
Metal Plates ◽  
Computer Aided ◽  
Advanced Computer

The present paper is part of the study to develop the advanced computer aided manufacture (CAM) system called the changeable die system (CDS) that applies the cold-forming technique to produce curved metal plates with complex, three-dimensional geometry. This paper focuses on the algorithm of predicting the spring-back behavior using nonlinear finite element method, which is a key element within the framework of the CDS process. The validity of the algorithm is confirmed by comparison with experimental results obtained by the CDS machine in the cold-forming process of curved steel plates.

Prediction and Optimization of Deformations in Coupling Mechanism Based Laser Forming of Sheet Metals

2019 ◽  
Vol 969 ◽  
pp. 552-557
Author(s):  
Kuntal Maji
Keyword(s):  
Process Parameters ◽  
Metal Forming ◽  
Three Dimensional ◽  
Laser Forming ◽  
Coupling Mechanism ◽  
Sheet Metals ◽  
Forming Process ◽  
Out Of Plane ◽  
Metal Forming Process ◽  
Plane Deformations

Fabricating three dimensional shaped surfaces from flat sheet metals by laser forming, both out-of-plane and in-plane deformations are required. This article presents the modeling of coupling mechanism activated laser forming of sheet metals based on experimental data for prediction and optimization of bending and thickening deformations. Experiments were performed based on a central composite design of experiments on coupling mechanism based laser metal forming process considering the input process parameters like laser power, scan speed and spot diameter, bending and thickening were taken as the outputs. Neural network and neuro-fuzzy system-based models were developed to carry out both forward and inverse modeling of the laser metal forming process under the coupling mechanism. Multi-objective optimization based on the non-dominated sorting genetic algorithm was used to obtain multiple optimal solutions to achieve different amounts of out-of-plane and in-plane deformations. The proposed method could guide for a suitable selection of the process parameters to produce three-dimensional shapes utilizing coupling mechanism-based laser forming using multiple laser line heating.

Laser Forming of Varying Thickness Plate—Part I: Process Analysis

2005 ◽  
Vol 128 (3) ◽  
pp. 634-641 ◽  
Author(s):  
Peng Cheng ◽  
Yajun Fan ◽  
Jie Zhang ◽  
Y. Lawrence Yao ◽  
David P. Mika ◽  
...  
Keyword(s):  
Process Analysis ◽  
Scanning Speed ◽  
Spot Size ◽  
Laser Forming ◽  
Thickness Variation ◽  
Complex Structures ◽  
Forming Process ◽  
Forming Mechanism ◽  
Varying Thickness ◽  
Wide Range

High-intensity laser beams can be used to heat and bend metal plates, but the mechanisms of the laser forming (LF) process are not well understood or precisely controllable. The objective of the National Institute of Standards and Technology sponsored project “Laser Forming of Complex Structures” is to develop technologies for a controllable, repeatable laser forming process that shapes and reshapes a wide range of complex structures such as compressor airfoils that are complex 3D geometries with large thickness variation. In order to apply laser forming to complex 3D geometries, the process analysis and process synthesis (design process parameters such as scanning paths and heating conditions for a desired shape) of LF of varying thickness plate are conducted in this paper. In this study, experimental, numerical, and analytical methods are used to investigate the bending mechanism and parametric effects on the deformation characteristics of varying thickness plates. A transition of the laser forming mechanism was found to occur along the scanning path when the thickness varies. The effect of scanning speed, beam spot size, and multiple scanning on the degree of bending was investigated. The proposed analytical model can predict the bending angle and angle variations for laser forming of varying thickness plate.

scholarly journals Numerical Simulation and Experimental Confirmation of a Bimetallic Pipe Forming Process

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3561
Author(s):  
Zhiqiang Dong ◽  
Zhenzhen Xu ◽  
Wenke Wang ◽  
Zongyue Bi ◽  
Jianxun Zhang
Keyword(s):  
Stress Distribution ◽  
Three Dimensional ◽  
Good Choice ◽  
Image Correlation ◽  
Residual Tensile Stress ◽  
Three Dimensional Model ◽  
Forming Process ◽  
Corrosion Failure ◽  
Cold Forming ◽  
Bimetallic Pipe

Most oil and gas is transported by pipeline, and corrosion causes a great threat to the service life of the pipeline; bimetallic pipe, which combines the advantages of good mechanical properties, good corrosion resistance, and relatively low price, is a good choice for high-pressure and corrosion-resistant pipe, but its manufacturing process and stress distribution are more complex than single metal pipe. JCO is a widely used cold forming method for pipes which is named by the shape of the plate in the forming process, i.e. J-shape, C-shape and O-shape, and the forming process is an important parameter that determines the level of imperfections and residual stresses in a pipe, and residual tensile stress will accelerate corrosion failure of the pipe. In this study, the three-dimensional (3D) finite element method (FEM) is used to simulate the pre-bending and JCO forming process of a 2205/X65 bimetallic pipe. The model and the simulated results are validated by digital image correlation (DIC) experimental and the opening width of the formed pipe billet, respectively. The influence factors of the stresses are studied. Further, a two-dimensional (2D) model is established to study the characteristics of bimetallic plate bending and the stress distribution at the interface of different materials, and the results are compared with that of three-dimensional model.

Numerical and Experimental Analysis for Large Radius Deformation of Stainless Steels by Laser Forming Process

2005 ◽  
Author(s):  
J. Pennuto ◽  
J. Choi
Keyword(s):  
Experimental Data ◽  
Phase Transformation ◽  
Experimental Testing ◽  
Three Dimensional ◽  
Laser Forming ◽  
Bend Angle ◽  
Large Radius ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Forming Process

In an effort to develop a process free of dedicated tooling, this research seeks to study large radius deformation by laser forming. Experimental testing was conducted to determine how the laser parameters affect the single pass output bend angle as well as the additive bend angle from successive parallel, evenly spaced laser irradiations. As an extension of the previous developments, this work seeks to develop a three-dimensional model to simulate the multi-scan laser process. It is of interest to determine how sophisticated a three-dimensional case is required for sufficient agreement to experimental data. The simulated results of bending angle are compared with experimental data and suggestions for future study include the implementation of phase transformation and microstructure data within the model to account for stress development resulting from phase transformation and grain growth.

scholarly journals Effects of Forced Cooling In Laser Forming

2019 ◽  
Vol 8 (10) ◽  
pp. 3782-3787
Keyword(s):  
Numerical Model ◽  
Research Work ◽  
Three Dimensional ◽  
Weight Ratio ◽  
Laser Forming ◽  
Beam Diameter ◽  
Forming Process ◽  
Scanning Velocity ◽  
Cooling Conditions ◽  
Forced Cooling

This paper presents the numerical bending studies of the alloy sheet of Magnesium M1A to achieve the bigger bending angle in a single laser forming process. A three-dimensional model of finite elements was created and different simulations were performed for sheet laser bending. Magnesium alloys are difficult-to-form yet have huge applications in automobile and aerospace industries because of its high strength to weight ratio. To study the sheet bending method and effect of various process parameters including laser scanning velocity, beam diameter and laser power, a three-dimensional numerical model was developed. The developed numerical model was designed with ABAQUS Simulia and validated with the published numerical model. On the validated numerical model, a further number of simulations were performed to understand the effects of forced cooling conditions in single scan laser forming process. This research work concluded that forced cooling conditions in laser forming can be used to increase the bend angle in a single scan.

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