Optimization of Laser Transmission Welding Process for Thermoplastic Composite Parts using Thermo-Mechanical Simulation

Abstract

An innovative methodology for the thermo-mechanical simulation of the laser transmission welding (LTW) process for thermoplastic components is presented. The work consists of two parts. In the first part, a finite element (FE) thermal model is developed, for the prediction of the transient spatial temperature history developing during the LTW process. Experimental measurements have been used for the calibration of the developed thermal model. Through this thermal model, a parametric study on the main welding parameters is performed, in order to investigate their effect on the maximum temperature. Using the parametric study results, the optimal combination of the welding parameters is derived taking into account the welding cost. In the second part, the optimized set is used in a model developed for the thermo-mechanical simulation of the LTW process and the calculation of the thermal stresses, strains, and distortions of the welded parts. The benefit of the proposed methodology is that it offers the capability of optimizing the LTW process, and also provides a reliable estimation of the developed temperature, as well as the thermal stress and strain fields reducing the experimental effort.

Laser transmission welding of composites-Part A: Thermo-physical and optical characterization of materials

“…And finally the model permits to determine the three dimensional temperature fields, during the welding process. In order to compute the temperature field, the optical and thermal properties of the welded materials are necessary as input parameters in order to model the process properly [4][5][6][7][8][9][10][11][12][13]. These properties vary depending on the component material (fiber and matrix), their assembly, and the volume fraction in the considered composite [14].…”

Analytical and numerical modeling of light scattering in composite transmission laser welding process

“…Low energy values can lead to a weak joint with low strength, while high energy values may cause degradation and vaporization phenomena; in both cases, a bad joint quality is obtained. Consequently, the energy delivered on the surfaces needs to be optimized for every process application [3]. A growing numbers of applications of composite thermoplastics have lead to an increasing interest in research in the field of laser welding.…”

Numerical analysis of thermoplastic composites laser welding using ray tracing method

“…Unlike pure thermoplastic material welding [3,4], accurate knowledge of thermal properties evolution with temperature is not the major parameter in weldability optimization of composite parts. In the case of thermoplastic matrix composites, the most important step is the laser beam diffusion through the transparent substrate [2,11].…”

“…Complex part shapes and/or weld seam geometry can be envisaged, and it overcomes the environmental difficulties related to existing gluing processes. In this study we propose to develop numerical tools in order to optimize [2] the laser welding process. Thermal composite properties depend on individual components properties they also depend on the relative constituent arrangement.…”