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

Álvaro Navarrete,Felipe Cook,Marcela Cruchaga,Diego Celentano,Claudio García-Herrera

doi:10.3390/ma11071262

Álvaro Navarrete, Felipe Cook + Show 3 more

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https://doi.org/10.3390/ma11071262

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Abstract

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.

Highlights

Laser forming is a flexible and dieless forming technique in which laser-induced plastic deformations caused by non-uniform thermal stresses bend a sheet metal without any hard forming tool or external forces
The experimental measurements of the sheet laser forming tests, included in Section 2.1, together with the corresponding numerical results computed with the thermomechanical formulation, briefly described in Section 2.2, are separately presented and discussed in what follows
For the ranges of the operating variables chosen in this study, greater bending angles are obtained for greater levels of scanning line width and smaller levels of both separation between lines and transversal laser beam scanning velocity

Summary

Introduction

Laser forming is a flexible and dieless forming technique in which laser-induced plastic deformations caused by non-uniform thermal stresses bend a sheet metal without any hard forming tool or external forces. In comparison with conventional metal forming methods, the laser forming process has many advantages, for example, it is suitable for low-volume production and/or rapid prototyping of sheet metals, it can shape complex curved surface in either very small of very big parts, and it practically prevents the occurrence of springback, even in the materials exhibiting a large elastic limit at room temperature. This process offers a significant potential value to industries such as aerospace, shipbuilding, and microelectronics [1,2]. On the other hand, added to experimental procedures, the development of models with such a complex process can help to provide a basis for a better understanding of the various phenomena involved and, make the application of laser forming a feasible and profitable to industry

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