Experimental and Numerical Analysis of Low Output Power Laser Bending of Thin Steel Sheets

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Vicente Stevens ◽  
Diego Celentano ◽  
Jorge Ramos-Grez ◽  
Magdalena Walczak
Keyword(s):  
Numerical Analysis ◽  
Output Power ◽  
Laser Forming ◽  
Element Formulation ◽  
Temperature Dependent ◽  
Forming Process ◽  
Laser Bending ◽  
Operating Variables ◽  
Steel Sheets ◽  
Thermal Boundary Conditions

This work presents an experimental and numerical analysis of a low output power single-pass laser forming process applied to thin stainless steel sheets. To this end, the proposed methodology consists in four stages respectively devoted to material characterization via tensile testing, estimation of thermal boundary conditions present in laser forming, realization of laser bending tests for two sets of operating variables, and finally, numerical simulation of this process carried out with a coupled thermomechanical finite element formulation accounting for large plastic strains, temperature-dependent material properties and convection–radiation phenomena. The numerical analysis, focused on the description of the evolution of the thermomechanical material response, is found to provide a satisfactory experimental validation of the final bending angle for two laser forming cases with different operating variables. In both cases, the predicted high temperature gradients occurring across the sample thickness show that the deformation process is mainly governed by the thermal gradient mechanism.

An Experimental Study on Bending Process of AISI 304 Steel Sheets by using Diode Laser Forming

2014 ◽  
Vol 1 (1) ◽  
pp. 14-30
Author(s):  
Alfonso Paoletti
Keyword(s):  
Laser Beam ◽  
Diode Laser ◽  
Process Parameters ◽  
Laser Forming ◽  
Laser Bending ◽  
Aisi 304 ◽  
Steel Sheets ◽  
Metal Sheets ◽  
Bending Process ◽  
Aisi 304 Steel

Laser bending is a promising technique utilised in order to deform metal sheets that offers the advantage of requiring no hard tooling and no external forces, thus reducing cost and increasing flexibility. Laser forming involves a complex interaction of many process parameters, ranging from those connected with the irradiation of the laser beam to those regarding the thermal and mechanical properties of the workpiece material. The present work is focused on the laser bending of AISI 304 steel sheets by using of a diode laser. The influence of process parameters, such as the power of laser beam and the scanning speed as well as the metal sheet thickness on the bending angle has been taken into account. The investigation has also analysed the effect of rolling direction of the metal sheets and the conditions of cooling on the bending process.

Temperature Gradient-Based Laser Bending of Full Plates and Plates With Cutout

2020 ◽  
pp. 270-305
Author(s):  
Paramasivan Kalvettukaran ◽  
Sandip Das ◽  
Sundar Marimuthu ◽  
Dipten Misra
Keyword(s):  
Laser Forming ◽  
Forming Process ◽  
Laser Bending ◽  
Bending Angle ◽  
Aisi 304 ◽  
Thermally Induced ◽  
Bending Process ◽  
Gradient Based ◽  
Different Dimensions ◽  
Different Shapes

The laser bending process, also called the laser forming process, consists of irradiating the surface of a sheet or a plate by means of a moving laser beam with a predefined scanning strategy to generate the desired shape through thermally induced residual stress. This chapter presents the mechanisms of a laser bending process and the technological aspects concerning laser v-bending of rectangular AISI 304 plates for full plates and plates with a central cutout at its middle to highlight the process fundamentals and how processing affects the final bending angle of the workpieces. Laser bending involving plates with a cutout will have numerous applications for car bodies, such as front and rear panels where bending is required to be performed on panels with cutout geometries. To investigate the effects of shape and size of the cutout on temperature distribution, stress distribution, and final bending angle, different shapes such as circular, ellipse, rectangular, and square, as well as different dimensions of cutouts have been chosen.

Research on the Mechanisms of Laser Forming for the Micro-Structural Element

2008 ◽  
Vol 575-578 ◽  
pp. 1145-1150
Author(s):  
Ying Jin ◽  
Jian Hua Wu ◽  
Yong Jun Shi ◽  
Hong Shen ◽  
Zheng Qiang Yao
Keyword(s):  
Thermal Stresses ◽  
Element Model ◽  
Laser Forming ◽  
Forming Process ◽  
Structural Element ◽  
Laser Bending ◽  
Forming Mechanism ◽  
Thermal Transfer ◽  
Conventional Analysis ◽  
The Finite Element Model

Laser forming of a micro-structural element involves a complex thermoplastic process. Numerous efforts had been made on the mechanisms of laser forming for macro-size elements, such as temperature gradient mechanism, buckling mechanism and upsetting mechanism, etc. It is found that the three mechanisms cannot depict fully the process of deformation in the macro-size element forming, let alone meet the needs of the micro-size one. Considering the laser inducing thermal stresses with size factors differing from the conventional analysis, it is essential to reveal the mechanisms dominating the forming process to accurately control the bending angle of a tiny plate. By studying the thermal transfer and elastic-plastic deformation of micro-structural element laser forming, the forming mechanism is explained within the micro size. The finite element model for laser bending is constructed for simulation. The stimulation results are agreement with the experimental data.

scholarly journals Numerical Simulation and Experimental Validation of Sheet Laser Forming Processes Using General Scanning Paths

Materials ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1262
Author(s):  
Álvaro Navarrete ◽  
Felipe Cook ◽  
Diego Celentano ◽  
Marcela Cruchaga ◽  
Claudio García-Herrera
Keyword(s):  
Numerical Simulation ◽  
Material Properties ◽  
Experimental Validation ◽  
Piecewise Linear ◽  
Scanning Speed ◽  
Laser Forming ◽  
Element Formulation ◽  
Temperature Dependent ◽  
Modeling Framework ◽  
Good Agreement

This work presents numerical simulations and an experimental validation of sheet laser forming processes using general scanning paths with different laser beam operating parameters (i.e., power, diameter, and scanning speed) in two specific graphite coated stainless steel blanks (i.e., with thicknesses of 0.3 mm and 0.6 mm for the AISI 302 and 304 alloys, respectively). To this end, three specific laser forming tests involving single S-shaped, multiple circular, and single piecewise linear scanning paths are carried out. On the other hand, the numerical simulation of these tests is performed via a coupled thermomechanical finite element formulation, accounting for large viscoplastic strains, temperature-dependent material properties, and convection-radiation phenomena. The final bending angles provided by this model are found to be in good agreement with the experimental measurements for all of the cases studied. Therefore, this modeling framework can be established as a reliable approach to predict the material thermomechanical response during sheet laser forming using general scanning paths.

Temperature Gradient Mechanism on Laser Bending of Borosilicate Glass Sheet

2010 ◽  
Vol 132 (1) ◽  
Author(s):  
Dongjiang Wu ◽  
Guangyi Ma ◽  
Fangyong Niu ◽  
Dongming Guo
Keyword(s):  
Temperature Gradient ◽  
Borosilicate Glass ◽  
Fe Simulation ◽  
Glass Sheet ◽  
Laser Forming ◽  
Thickness Direction ◽  
Forming Process ◽  
Primary Defect ◽  
Laser Bending ◽  
Forming Mechanism

The present work is a research on the laser forming process of borosilicate glass sheet. The laser forming mechanism was analyzed, and the temperature gradient mechanism was considered as the main forming mechanism of glass bending. According to the experimental results, a thermomechanical finite element (FE)-simulation was applied for investigating the temperature distribution and thermal stress in the thickness direction of the specimen. Cracks, as the primary defect, were summarized to three kinds: “Y” cracks, straight cracks, and arc cracks, while their forming mechanisms were proposed.

Temperature Monitoring during Laser Beam Forming of Steel Sheets

2014 ◽  
Vol 622-623 ◽  
pp. 811-818
Author(s):  
Stephen Akinlabi ◽  
Esther Titilayo Akinlabi
Keyword(s):  
Laser Beam ◽  
Temperature Monitoring ◽  
Laser Forming ◽  
Great Promise ◽  
Beam Forming ◽  
Measured Temperature ◽  
Data Logger ◽  
Forming Process ◽  
Line Energy ◽  
Steel Sheets

Laser Beam Forming is a flexible manufacturing process with great promise for sheet and metal forming, hence, considered as a novel manufacturing method for forming and shaping of metallic components. Being a thermo-mechanical forming process that enables parts or components to be formed with external heat of a laser beam, it is important to monitor and measure the temperature during the laser forming process in order to ensure the integrity of the processed components. This study reports on the temperature monitoring and measurement during laser beam forming process of steel sheets. The experimental design followed the L-27 Taguchi Orthogonal Array. The temperature of nine sets of samples laser beamed formed at different process parameters were monitored using the thermocouple data logger. The temperature for all the components formed at the nine parameter windows were analysed during the process. Hence, it was observed that the measured temperature increases with the increasing line energy during the laser beam forming process.

scholarly journals Recent Advances in the Laser Forming Process: A Review

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1472
Author(s):  
Mehdi Safari ◽  
Ricardo Alves de Sousa ◽  
Jalal Joudaki
Keyword(s):  
Process Parameters ◽  
Optimization Technique ◽  
Laser Forming ◽  
Forming Process ◽  
Laser Bending ◽  
Heating Source ◽  
Fiber Metal ◽  
Local Softening ◽  
Doubly Curved ◽  
And Control

Laser forming is an emerging manufacturing process capable of producing either uncomplicated and complicated shapes by employing a concentrated heating source. The heat source movement creates local softening, and a plastic strain will be induced during the rise of temperature and the subsequent cooling. This contactless forming process may be used for the simple bending of sheets and tubes or fabrication of doubly-curved parts. Different studies have been carried out over recent years to understand the mechanism of forming and predicting the bending angle. The analysis of process parameters and search for optimized manufacturing conditions are among the most discussed topics. This review describes the main recent findings in the laser forming of single and multilayer sheets, composite and fiber-metal laminate plates, force assisted laser bending, tube bending by laser beam, the optimization technique implemented for process parameters selection and control, doubly-curved parts, and the analytical solutions in laser bending. The main focus is set to the researches published since 2015.

Numerical Simulation of Laser Bending of Thin Plate Stress Analysis and Prediction

2011 ◽  
Vol 227 ◽  
pp. 27-30
Author(s):  
Toufik Tamsaout ◽  
El Hachemi Amara
Keyword(s):  
Temperature Field ◽  
Analytical Modeling ◽  
Numerical Study ◽  
Numerical Approach ◽  
Laser Forming ◽  
Forming Process ◽  
Laser Bending ◽  
Mechanical Coupling ◽  
Bending Of Thin Plate

Laser forming is a technique consisting in the design and the construction of complex metallic work pieces with special shapes difficult to achieve with the conventional techniques. By using lasers, the main advantage of the process is that it is contactless and does not require any external force. It offers also more flexibility for a lower price. This kind of processing interests the industries that use the stamping or other costly ways for prototypes such as in the aero-spatial, automotive, naval and microelectronics industries. The analytical modeling of laser forming process is often complex or impossible to achieve, since the dimensions and the mechanical properties change with the time and in the space. Therefore, the numerical approach is more suitable for laser forming modeling. Our numerical study is divided into two models, the first one is a purely thermal treatment which allows the determination of the temperature field produced by a laser pass, and the second one consists in the thermo-mechanical coupling treatment. The temperature field resulting from the first stage is used to calculate the stress field, the deformations and the bending angle of the plate.

An Analytical Study on Laser Forming Process of Sheet Metals, Using New Elasto-Plastic Temperature Dependent Material Model

2012 ◽  
Vol 622-623 ◽  
pp. 569-574 ◽  
Author(s):  
Shams Torabnia ◽  
Afshin Banazadeh
Keyword(s):  
Laser Beam ◽  
Sheet Metal ◽  
Analytical Model ◽  
Plastic Material ◽  
Material Model ◽  
Laser Forming ◽  
Sheet Metals ◽  
Temperature Dependent ◽  
Forming Process ◽  
Heated Zone

The laser forming process is one of the last technologies on forming of sheet metals with laser beam heat distribution. In this process laser beam moves across the top surface of the sheet metal and the heated zone expands and causes a great moment that deforms the sheet metal. Subsequently, the heated zone gets cooled and provides a reverse strain and moment. The final bending angle is a combination of two phases. Due to the complexity of the process, it is studied with different approaches; FEM analysis and analytical as well as empirical methods. The laser forming is a sensible process regarding the material properties. Also, because of the temperature change during the process, it is important to use a temperature dependent model. In this study The FEM model is proposed for simulation of the mechanism. Based on the simulation results, an integrated analytical model is then developed by a new elasto-plastic material model considering linear strain hardening, combined with the temperature dependent mechanical and physical properties. In addition, the temperature dependent tangential modulus is used instead of the yield point of the material to improve accuracy in the plastic deformation phase. Finally, the analytical model is compared with the FEM standard code, which showed a great conformity.

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