https://cmapspublic3.ihmc.us/rid=1LTYVM9D8-24ZKHGG-2938/Welding%20methods%20for%20joining%20thermoplastic%20polymers.pdf

Welding methods for joining thermoplastic polymers for the hermetic enclosure of medical devices

This is an accepted manuscript of an article published by Elsevier in Additive Manufacturing on 02/10/2021, available online: https://doi.org/10.1016/j.addma.2021.102378 
The accepted version of the publication may differ from the final published version.

Fused Deposition Modelling: Current Status, Methodology, Applications and Future Prospects

Laser-Assisted Metal and Plastic bonding (LAMP) of AISI304 sheets with polycarbonate sheets is investigated in this work. The process was performed by means of a high power diode laser with a maximum power of 200 W. The study introduces an integrated experimental approach aimed at understanding how the main process conditions (laser power and scanning speed) influence the direct-bonds quality, dimensions and presence of defects. To this end, the bonds dimension, shear strength, formation and dimension of bubbles in the bonded region were related to the temperature measurements and process parameters. According to the achieved results, the processing window that enables a good adhesion of the two materials is relatively small; this is due the activation of the adhesion phenomena that require overcoming an energy threshold. However, excessive energy levels reduce the bonds strength due to the increase in defects (bubbles) dimension that may combine (coalescence) leading to the formation of a central tunnel where the two substrates are completely detached.

Laser-assisted direct joining of AISI304 stainless steel with polycarbonate sheets: Thermal analysis, mechanical characterization, and bonds morphology

The dissimilar full depth laser-butt welding of low carbon steel and austenitic steel AISI 316 was investigated using CW 1.5 kW CO 2 laser. The effect of laser power (1.1–1.43 kW), welding speed (25–75 cm/min) and focal point position (−0.8 to −0.2 mm) on the weld-bead geometry (i.e. weld-bead area, A ; upper width, W u ; lower width, W l and middle width, W m ) and on the operating cost C was investigated using response surface methodology (RSM). The experimental plan was based on Box–Behnken design; linear and quadratic polynomial equations for predicting the weld-bead widthness references were developed. The results indicate that the proposed models predict the responses adequately within the limits of welding parameters being used. The regression equations were used to find optimum welding conditions for the desired geometric criteria.

Weld-bead profile and costs optimisation of the CO2 dissimilar laser welding process of low carbon steel and austenitic steel AISI316

In this paper, an experimental investigation on diode laser transmission welding of dissimilar thermoplastics between PMMA (polymethyl methacrylate) and ABS (acrylonitrile butadiene styrene) has been carried out. The effect of the laser welding parameters such as laser power, welding speed, stand-off distance and clamp pressure on weld strength and weld width is investigated using response surface methodology (RSM). Planned experiments and subsequent analyses are carried out to develop the mathematical models to establish the correlation between the process parameters and the responses. The adequacy of the developed models is tested using the sequential F -test, lack-of-fit test and the analysis-of-variance (ANOVA) technique. A numerical multi-objective simultaneous optimization technique, in which the RSM is incorporated, is used to find the optimum solutions, according to the desired optimization criteria. In addition to that, a graphical optimization technique is, also implemented which allow identifying a region in the graphic where optimal conditions lay on.

Experimental investigation on laser transmission welding of PMMA to ABS via response surface modeling

In the present work, a study is made to investigate the effects of process parameters, namely, laser power, welding speed, size of the laser beam and clamp pressure, on the lap-shear strength and weld-seam width for laser transmission welding of acrylic (polymethyl methacrylate), using a diode laser system. Response surface methodology (RSM) is employed to develop mathematical relationships between the welding process parameters and the output variables of the weld joint to determine the welding input parameters that lead to the desired weld quality. In addition, using response surface plots, the interaction effects of process parameters on the responses are analyzed and discussed. The statistical software Design-Expert v7 is used to establish the design matrix and to obtain the regression equations. The developed mathematical models are tested by analysis-of-variance (ANOVA) method to check their adequacy. Finally, a comparison is made between measured and calculated results, which are in good agreement. This indicates that the developed models can predict the responses adequately within the limits of welding parameters being used.

Prediction of weld strength and seam width for laser transmission welding of thermoplastic using response surface methodology

Finite element design and thermal analysis of an induction motor used for a hydraulic pumping system

Laser forming of sheet metal is the bending process, induced by thermal stress, which is produced in the sheet by laser irradiation. Laser forming of complex shapes requires the study of the effect of various irradiation paths. In this paper the deformation of a circular plate, subjected to a circular irradiation path, is studied through a sequentially coupled thermo-mechanical elasto-plastic simulation by finite element method. The quality of laser bending in terms of waviness parameters, e.g., waviness average, Ra, RMS value, Rq, etc. are reported in detail, with respect to number of sections and number of passes of heating, as well as, shifting of the starting point for irradiation. It is observed that discrete section heating in symmetry with shifting in starting point of irradiation in subsequent passes reduces the undesired waviness, which is caused, otherwise, due to continuous circular heating.

 Keywords: Laser forming, irradiation pattern, FEM

/pdf/finite-element-simulation-of-3-d-laser-forming-by-discrete-20mf2dqana.pdf

K. Venkadeshwaran

Papers

Prediction of weld strength and seam width for laser transmission welding of thermoplastic using response surface methodology

Finite element design and thermal analysis of an induction motor used for a hydraulic pumping system

Finite element simulation of 3-D laser forming by discrete section circle line heating

Fused deposition modelling of PLA reinforced with cellulose nano-crystals

Efficiency enhancement in a PV operated solar pump by effective design of VFD and tracking system