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In this work, the effects of process parameters such as laser output power, beam diameter and scan speed and also sheet thickness on the bending angle have been numerically investigated in the laser bending process. For this purpose, Abaqus software is used for investigating the effect of various process and sheet parameters on the bending angle. The results show that with increasing the laser output power, bending angle is increased. Also, the bending angle is decreased with increasing the beam diameter, scan speed and sheet thickness.

In recent years, laser bending has emerged as a new and very promising technique to form sheet metal by thermal residual stresses. There are many advantages of laser bending compared to conventional sheet bending. Among these are, design flexibility, production of complex shapes (which is not achievable by the conventional methods), forming of thick plates, possibility of rapid prototyping, etc. There have been done many researches in the laser bending process. Among them, some researches have been focused on the effect of process parameters on the obtained bending angle using analytical investigations. In 1994, Vollertsen [

In this work the effects of process parameters such as laser output power, beam diameter and scan speed and also sheet thickness on the bending angle have been investigated numerically in the laser bending process. For this purpose Abaqus software is used for investigating the effect of various process and sheet parameters. The results show that with increasing the laser output power, bending angle is increased. Also, the bending angle is decreased with increasing the beam diameter, scan speed, thickness and inertia moment.

In the numerical investigations, the finite element method has been used for thermal and mechanical analysis. For this purpose ABAQUS implicit code has been used. In these simulations, mechanical calculations can be decoupled from thermal ones. The reason is that energy dissipation due to plastic deformation is much less than laser energy used in the process and hence changes in temperature due to plastic work can be ignored. The surface heat flux distribution is computed according to Gaussian distribution from the following formula:

where

In this section, firstly it is necessary to validate numerical simulations with experimental tests. For this purpose, in the experiments a sample plate is made from mild steel with 100 mm (length) × 50 mm (width) and 1 mm (thickness). Then temperature profile on the bottom surface under the heat line is measured using a thermocouple (type K) stuck at this location. In this state, using a continuous wave CO_{2} laser with maximum power of 1200 Watts, processing parameters such as laser output power, beam diameter and scan velocity are adjusted as 200 Watts, 2 mm and 200 mm/min respectively. In the numerical simulation, temperature profile for the same location is extracted. In

It is important to note comparing between experimental and numerical temperature profiles is a powerful method for verification of numerical results. In the following sections effects of laser output power, scan speed, beam diameter and sheet thickness on the bending angle in laser bending process are investigated.

In

In

In

In

the thickness of the plate, obtained bending angle is decreased. The reason is that with increasing the sheet thickness, bending stiffness of the plate is increased and consequently obtained bending angle of the plate in the laser bending process decreased.

In this work, using finite element method effects of process parameters on the obtained bending angle of the plate in the laser bending process are investigated. For this purpose, Abaqus software is used and numerical simulations are verified with experimental tests in the temperature field. The results show that obtained bending angle of the plate is increased with increasing the laser output power and decreasing the scan speed, beam diameter and sheet thickness.

The work described in this paper was fully supported by a grant from Islamic Azad University, Aligoudarz branch (Research project title: Numerical investigation into the effect of Laser parameters on the bending angle in laser forming Process). The author would like to thank the Islamic Azad University, Aligoudarz branch for providing the research facilities and funds.