Show simple item record

dc.contributor.authorParkinson, Alexander
dc.contributor.otherQueen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.))en
dc.date2013-09-27 10:41:08.997en
dc.date.accessioned2013-09-27T14:47:36Z
dc.date.available2013-09-27T14:47:36Z
dc.date.issued2013-09-27
dc.identifier.urihttp://hdl.handle.net/1974/8327
dc.descriptionThesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2013-09-27 10:41:08.997en
dc.description.abstractLaser welding has great potential as a fast, non-contact joining method for thermoplastic parts. In the laser transmission welding of thermoplastics, light passes through a semi-transparent part to reach the weld interface. There, it is absorbed as heat, which causes melting and subsequent welding. The distribution and quantity of light reaching the interface are important for predicting the quality of a weld, but are experimentally difficult to estimate. A model for simulating the path of this laser light through these light-scattering plastic parts has been developed. The technique uses a Monte-Carlo approach to generate photon paths through the material, accounting for absorption, scattering and reflection between boundaries in the transparent polymer. It was assumed that any light escaping the bottom surface contributed to welding. The photon paths are then scaled according to the input beam profile in order to simulate non-Gaussian beam profiles. A method for determining the 3 independent optical parameters to accurately predict transmission and beam power distribution at the interface was established using experimental data for polycarbonate at 4 different glass fibre concentrations and polyamide-6 reinforced with 20% long glass fibres. Exit beam profiles and transmissions predicted by the simulation were found to be in generally good agreement (R2>0.90) with experimental measurements. The simulations allowed the prediction of transmission and power distributions at other thicknesses as well as information on reflection, energy absorption and power distributions at other thicknesses for these materials.en_US
dc.languageenen
dc.language.isoenen_US
dc.relation.ispartofseriesCanadian thesesen
dc.rightsThis publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.en
dc.subjectplasticen_US
dc.subjectweldingen_US
dc.subjectlaseren_US
dc.subjectopticsen_US
dc.titleModelling Laser Light Propagation in Thermoplastics Using Monte Carlo Simulationsen_US
dc.typethesisen_US
dc.description.degreeMasteren
dc.contributor.supervisorZak, Geneen
dc.contributor.supervisorBates, Philip J.en
dc.contributor.departmentMechanical and Materials Engineeringen


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record