scholarly journals An Analytical Model for Estimating the Bending Curvatures of Metal Sheets in Laser Peen Forming

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 462
Author(s):  
Yunxia Ye ◽  
Zeng Nie ◽  
Xu Huang ◽  
Xudong Ren ◽  
Lin Li
Keyword(s):  
Analytical Model ◽  
Laser Energy ◽  
Stress Gradient ◽  
Energy Coupling ◽  
Complex Stress ◽  
Force Balance ◽  
Thin Plates ◽  
Forming Process ◽  
2024 Aluminum Alloy ◽  
Peen Forming

Laser peen forming (LPF) is suitable for shaping sheet metals without the requirement for die/mold and without causing high temperatures. An analytical model for estimating the bending curvatures of LPF is convenient and necessary for better understanding of the physical processes involved. In this paper, we describe a new analytical model based on internal force balance and the energy transformation in LPF. Experiments on 2024 aluminum alloy sheets of 1–3 mm thickness were performed to validate the analytical model. The results showed that for 1 mm and 3 mm thick–thin plates, the curvature obtained by the analytical model changes from −14 × 10−4 mm−1 and −1 × 10−4 mm−1 to 55 × 10−4 mm−1 and −21 × 10−4 mm−1, respectively, with the increase of laser energy, which is consistent with the experimental trend. So, when either the stress gradient mechanism (SGM) or the shock bending mechanism (SBM) overwhelmingly dominated the forming process, the analytical model could give relatively accurate predicted curvatures compared with the experimental data. Under those conditions where SGM and SBM were comparable, the accuracy of the model was low, because of the complex stress distributions within the material, and the complex energy coupling process under these conditions.

Three-Dimensional Numerical Simulation and Experimental Study of Sheet Metal Bending by Laser Peen Forming

2010 ◽  
Vol 132 (6) ◽  
Author(s):  
Yongxiang Hu ◽  
Yefei Han ◽  
Zhenqiang Yao ◽  
Jun Hu
Keyword(s):  
Numerical Model ◽  
Sheet Metal ◽  
Laser Energy ◽  
Three Dimensional ◽  
Target Surface ◽  
Thick Sheet ◽  
Specimen Thickness ◽  
Forming Process ◽  
Form Complex ◽  
Peen Forming

Laser peen forming (LPF) is a purely mechanical forming method achieved through the use of laser energy to form complex shapes or to modify curvatures. It is flexible and independent of tool inaccuracies that result from wear and deflection. Its nonthermal process makes it possible to form without material degradation or even improve them by inducing compressive stress over the target surface. In the present study, a fully three-dimensional numerical model is developed to simulate the forming process of laser peen forming. The simulation procedure is composed of several steps mainly including the shock pressure prediction, the modal analysis, and the forming process calculation. System critical damping is introduced to prevent unnecessary long post-shock residual oscillations and to greatly decrease the solution time for simulation. The bending profiles and angles with different thicknesses are experimentally measured at different scanning lines and scanning velocities to understand the process and validate the numerical model. The calculated bending profiles and angles agree well with the trend of the measured results. But it is found that simulations with the Johnson–Cook model are more consistent, matching the experimental results for the thick sheet metal with a convex bending, while the elastic-perfectly-plastic model produces a better agreement even though with underestimated values for the thinner sheet metal with a concave bending. The reason for this phenomenon is discussed, combining the effects of strain rate and feature size. Both the simulation and the experiments show that a continuous decrease in bending angle from concave to convex is observed with increasing specimen thickness in general. Large bending distortion is easier to induce by generating a concave curvature with LPF, and the angle of bending distortion depends on the number of laser shocks.

Experiment and numerical simulation of micro dent fabricated by laser shocking 2024 aluminum alloy

2019 ◽  
Vol 16 (1) ◽  
pp. 156-168
Author(s):  
Yezhong Fang ◽  
Xiaotian Ji ◽  
Xingquan Zhang ◽  
Jun Wang ◽  
Bin Chen ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Laser Energy ◽  
Outer Edge ◽  
Residual Stress Field ◽  
Forming Process ◽  
Laser Shock Processing ◽  
2024 Aluminum Alloy ◽  
Element Analysis ◽  
Content Type ◽  
Forming Mechanism

Purpose The purpose of this paper is to investigate the dynamic forming process of the micro dent fabricated by laser shock processing on 2024-T3 aluminum alloy. The effect of laser pluse energy on the deformation of micro dent was also discussed in detail. Design/methodology/approach It uses finite element analysis method and the corresponding laser shocking experiment. Findings The results demonstrate that the dynamic formation process of micro dent lasts longer in comparison with the shock wave loading time, and the depths of micro dents increase with the increasing laser energy. In addition, laser shocking with higher energy can result in more obvious pileup occurred at the outer edge of micro dent. Originality/value Surface micro dents can serve as fluid reservoirs and traps of the wear debris, which can decrease the effects of the wear and friction in rolling and sliding interfaces. The investigations can not only be propitious to comprehensively understand the forming mechanism of laser-shocked dent, but also be beneficial to get sight into the residual stress field induced by laser shocking.

Analysis of Crimping of Large Diameter Welding Pipe

2014 ◽  
Vol 997 ◽  
pp. 517-521
Author(s):  
Li Feng Fan ◽  
Ying Gao ◽  
Jian Bin Yun ◽  
Lin Feng Dong
Keyword(s):  
Analytical Model ◽  
Large Diameter ◽  
Forming Process ◽  
Technical Parameters ◽  
Polynomial Curve ◽  
Welding Pipe ◽  
X80 Steel ◽  
Polynomial Curve Fitting ◽  
Effective Path ◽  
Submerged Arc

Crimping is widely used in production of large diameter submerged-arc welding pipes. Traditionally, the designers obtain the technical parameters for crimping from experience or trial-errors by experiments. To tackle this problem, a theoretical analytical model is proposed to analysis crimping forming process. In this paper, taking the crimping of X80 steel Φ1219mm×22mm×12000mm welding pipe for instance, the theoretical analytical model is constructed by quadratic polynomial curve fitting technique and mechanics theory. And it is verified by a comparison with experiment results. Thus, the presented model of this research provides an effective path to design crimping parameters.

Research on Deformation Prediction Method of Laser Melting Deposited Large-Sized Parts Based on Inherent Strain Method

2021 ◽  
Vol 871 ◽  
pp. 65-72
Author(s):  
Cheng Hong Duan ◽  
Xian Kun Cao ◽  
Ming Huang Zhao ◽  
Xiang Peng Luo
Keyword(s):  
Residual Stress ◽  
Laser Energy ◽  
Layer By Layer ◽  
Laser Melting ◽  
Forming Process ◽  
Deformation Prediction ◽  
Metal Parts ◽  
Inherent Strain ◽  
Inherent Strain Method ◽  
Strain Method

In the process of metal parts fabricated by Laser Melting Deposition (LMD), a high temperature gradient will generate due to the instantaneous high laser energy input, which will cause residual stress in the formed part of metal parts, the residual stress will result in defects like warping deformation or even cracking. In this paper, a finite element method based on inherent strain method is proposed to predict the deformation of metal parts fabricated by LMD. Firstly, combing with the birth and death element technology, a local model is established to simulate the layer-by-layer deposition in the LMD forming process, and the values of inherent strain is obtained. Secondly, the obtained inherent strain values is applied to large-sized part layer by layer, and the final deformation of large-sized part is calculated. Based on the proposed method, the efficiency of deformation prediction of large-sized metal parts fabricated by LMD could be effectively improved.

Theoretical Analysis of Laser Shock Bulging Forming

2012 ◽  
Vol 472-475 ◽  
pp. 2480-2483 ◽  
Author(s):  
Guo Fang Zhang ◽  
Zhong Ji ◽  
Jing Liu ◽  
Chao Zheng ◽  
Jian Hua Zhang
Keyword(s):  
High Pressure ◽  
Theoretical Analysis ◽  
Analytical Model ◽  
Pulse Energy ◽  
Shock Pressure ◽  
Laser Shock ◽  
Plastic Response ◽  
Forming Process ◽  
Laser Shock Forming ◽  
Plastic Forming

Laser shock forming (LSF) is a novel plastic forming process which utilizes high-pressure plasma to deform thin metals to 3D configurations. The plastic response of a circular plate in laser shock bulging forming was theoretically studied. A simplified shock pressure model was established and then an analytical model was proposed to calculate the deflection. The results show that the deflection increases with increasing pulse energy and the deformation profiles calculated by the analytical model agree well with those of experiment.

Research on the Finite Element Simulation of the Laser Shock Forming of TC4 Titanium Alloy

2016 ◽  
Vol 693 ◽  
pp. 1121-1128 ◽  
Author(s):  
Guo He Li ◽  
David Mbukwa ◽  
Wei Zhao
Keyword(s):  
Finite Element ◽  
Sheet Metal ◽  
Laser Energy ◽  
Sheet Thickness ◽  
High Amplitude ◽  
Laser Spot ◽  
Laser Shock ◽  
Forming Process ◽  
Element Analysis ◽  
Laser Shock Forming

laser shock forming, which combines the metal forming and material modification, is a non-mode, flexible forming new technology using laser-induced force effect of high amplitude shock waves to obtain the plastic deformation of sheet metal. in this paper, the simulation of laser shock forming process of tc4 sheet metal was carried out through the commercial finite element analysis software abaqus. the influence of the sheet thickness, laser energy, constraints aperture and laser spot spacing on the sheet metal deformation are investigated. the results show that: with the increase of sheet thickness, the deformation range of sheet decreases, and the amplitude of deformation decreases firstly and then increases. the deformation increases linearly with the increase of laser energy. the larger boundary constraint aperture leads to the larger deformation of sheet metal. there are no obvious influence on the forming accuracy when an opposite laser spot spacing is adopted. therefore, under the condition of meeting the accuracy requirement, for improving the efficiency, adopting a certain laser spot spacing to finish the forming should be considered.

Comparison of Analytical Model to Experimental Results and Numerical Simulations for Tailor Welded Blank Forming

2004 ◽  
Author(s):  
Matt Bravar ◽  
Brad Kinsey ◽  
Neil Krishnan
Keyword(s):  
Numerical Simulations ◽  
Analytical Model ◽  
Weld Line ◽  
Experimental Results ◽  
Forming Process ◽  
Tailor Welded Blanks ◽  
Industrial Utilization ◽  
Initial Placement ◽  
Weld Line Movement ◽  
Line Movement

Tailor Welded Blanks offer several notable benefits including decreased part weight, reduced manufacturing costs, and improved dimensional consistency. However the reduced formability and other characteristics of the forming process associated with TWBs has limited the industrial utilization of this blank type. One concern with TWB forming is that weld line movement occurs which alters the final location of the various materials in the TWB combination. In this paper, an analytical model to predict the initial weld line placement necessary to satisfy the desired, final weld line location is presented. Good agreement between the model, experimental results, and numerical simulations with respect to weld line movement and initial placement was obtained for a symmetric, steel TWB case and a non-symmetric, Aluminum TWB case.

Temporal Pulse Shaping and Optimization in Ultrafast Laser Ablation of Materials

2003 ◽  
Vol 780 ◽  
Author(s):  
R. Stoian ◽  
S. Winkler ◽  
M. Hildebrand ◽  
M. Boyle ◽  
A. Thoss ◽  
...  
Keyword(s):  
Pulse Shaping ◽  
Laser Energy ◽  
Energy Coupling ◽  
Laser Pulses ◽  
Ultrafast Laser ◽  
Ultrashort Laser Pulses ◽  
Adaptive Optimization ◽  
Ultrafast Laser Pulses ◽  
Energy Delivery ◽  
Optimal Processing

The possibility of phase manipulation and temporal tailoring of ultrashort laser pulses enables new opportunities for optimal processing of materials. Phase-manipulated ultrafast laser pulses allow adapting the laser energy delivery rate to the material properties for optimal processing laying the groundwork for adaptive optimization in materials structuring. Different materials respond with specific reaction pathways to the sudden energy input depending on the efficiency of electron generation and on the ability to release the energy into the lattice. The sequential energy delivery with judiciously chosen pulse trains may induce softening of the material during the initial steps of excitation and change the energy coupling for the subsequent steps. We show that this can result in lower stress, cleaner structures, and allow for a materialdependent optimization process.

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