A Three-Dimensional Numerical Model for Predicting the Weld Bead Geometry Characteristics in Laser Overlap Welding of Low Carbon Galvanized Steel

Abstract

Laser welding (LW) becomes one of the most economical high quality joining processes. LW offers the advantage of very controlled heat input resulting in low distortion and the ability to weld heat sensitive components. To exploit efficiently the benefits presented by LW, it is necessary to develop an integrated approach to identify and control the welding process variables in order to produce the desired weld characteristics without being forced to use the traditional and fastidious trial and error procedures. The paper presents a study of weld bead geometry characteristics prediction for laser overlap welding of low carbon galvanized steel using 3D numerical modelling and experimental validation. The temperature dependent material properties, metallurgical transformations and enthalpy method constitute the foundation of the proposed modelling approach. An adaptive 3D heat source is adopted to simulate both keyhole and conduction mode of the LW process. The simulations are performed using 3D finite element model on commercial software. The model is used to estimate the weld bead geometry characteristics for various LW parameters, such as laser power, welding speed and laser beam diameter. The calibration and validation of the 3D numerical model are based on experimental data achieved using a 3 kW Nd:Yag laser system, a structured experimental design and confirmed statistical analysis tools. The results reveal that the modelling approach can provide not only a consistent and accurate prediction of the weld characteristics under variable welding parameters and conditions but also a comprehensive and quantitative analysis of process parameters effects on the weld quality. The results show great concordance between predicted and measured values for weld bead geometry characteristics, such as depth of penetration, bead width at the top surface How to cite this paper: Oussaid, K. and El Ouafi, A.

A Study on Prediction of Weld Geometry in Laser Overlap Welding of Low Carbon Galvanized Steel Using ANN-Based Models

“…The upper and lower limits of factors are respectively 2000 to 3000 W for the power of the laser, 40 to 70 mm/s for the welding speed, 300 to 490 μm for the beam diameter and 0.05 to 0.15 mm for the Gap. The Data assigned for training and testing the various models are partly provided from an experimental investigation of laser welding process [15] while the other part is produced by a 3D FEM simulation [16]. In order to include the gap in the ANN modeling, the finite element model is adapted for each Gap value (0.05, 0.1 and 0.15 mm) by recalculating the calibration coefficients (m and n) of the heat source for each time step.…”

An Inhomogeneous Model for Laser Welding of Industrial Interest

“…where C(T(x, t)) is the volumetric specific heat, λ(T(x, t)) is the thermal conductivity, ∇T(x, t) is the temperature gradient, and Q l is the volumetric heat source due to the laser [11][12][13][14][15] formulated in parabolic frontiers with suitable boundary and initial conditions [11][12][13][14][15][16][17]. When the laser moves from an initial temperature T 0 , T(x, t) raises, for which the material, initially solid, begins to melt, highlighting the co-presence of solid-liquid (intermediate state) until the occurrence of the total melting of the material [18].…”

An Inhomogeneous Model for Laser Welding of Industrial Interest

“…where C(T (x, t)) is the volumetric specific heat, λ(T (x, t)) is the thermal conductivity, ∇T (x, t) is the temperature gradient and Q l is the volumetric heat source due to the laser [Ghosh et al 2013, Kaplan 2011, Unni et al 2021, Ragavendran et al 2021, Morosanu et al 2023; formulated in parabolic frontiers with suitable boundary and initial conditions [Ghosh et al 2013, Kaplan 2011, Oussaid et al 2019, Unni et al 2021, Ragavendran et al 2021, Morosanu et al 2023, Fakir et al 2018. When the laser moves, starting from an initial temperature T 0 , T (x, t) raises for which the material, initially solid, begins to melt highlighting the co-presence of solid-liquid (intermediate state) until the total melting of the material occurs [Sarila et al 2022].…”