An investigation of the failure mechanisms of thermoplastic composites at various rates of strain and temperatures

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dc.contributor.advisorMarcus, Kashifen_ZA
dc.contributor.advisorNurick, Gerald Nen_ZA
dc.contributor.authorNetangaheni, Phumudzo Ten_ZA
dc.date.accessioned2014-10-18T05:45:34Z
dc.date.available2014-10-18T05:45:34Z
dc.date.issued2003en_ZA
dc.descriptionIncludes bibliographical references .en_ZA
dc.description.abstractThe focus of this project is on the deformation behaviour of thermoplastic composites. The materials used were polypropylene and polyamide resins with glass fibres and talc as fillers. These materials were provided by PLASTAMID (pty) ltd. The injection moulded specimens of polypropylene, polyamide 6-6, 30% talc filled polypropylene, 30% short glass fibre reinforced polypropylene and 30% short glass fibre reinforced polyamide 6-6 were tested in tension, flexure and impact (lzod, Charpy and drop-weight). Two different injection-moulding machines were used for specimen manufacture. These were an automated injection moulding machine simulating good control of processing conditions and a simple hand operated injection moulding machine simulating different processing and cooling (crystallisation) conditions. The mechanical tests were performed at different rates of strain and temperatures. The mechanical results show higher ductility of the unfilled polypropylene material. The strength and the elastic modulus of the materials are different for different materials. Addition of short glass fibres enhances the mechanical properties of polypropylene and polyamide 6-6. Talc fillers reduce the tensile, Izod and Charpy impact properties of polypropylene while the flexural and dropweight impact strength is increased. Optical and scanning electron microscopy were used to observe the microstructural features and deformation behaviour such as matrix plastic deformation, matrix crazing and tearing, fibre-matrix debonding, fibre fracture, fibre orientation and crack propagation. These deformation behaviours are influenced by the test conditions such as strain rate, temperature and the type of the test conducted. The deformation behaviour is also dependent on the constituents of the material. The mechanical test response together with the macro- and microscopic features observed on the fracture surfaces of tested specimens are evidence of the various mechanisms of failure that take place in different thermoplastic composites. The understanding of the mechanical response and the failure mechanisms of thermoplastic matrix composites is important in the design and processing stages.en_ZA
dc.identifier.apacitationNetangaheni, P. T. (2003). <i>An investigation of the failure mechanisms of thermoplastic composites at various rates of strain and temperatures</i>. (Thesis). University of Cape Town ,Faculty of Engineering & the Built Environment ,Centre for Materials Engineering. Retrieved from http://hdl.handle.net/11427/8577en_ZA
dc.identifier.chicagocitationNetangaheni, Phumudzo T. <i>"An investigation of the failure mechanisms of thermoplastic composites at various rates of strain and temperatures."</i> Thesis., University of Cape Town ,Faculty of Engineering & the Built Environment ,Centre for Materials Engineering, 2003. http://hdl.handle.net/11427/8577en_ZA
dc.identifier.citationNetangaheni, P. 2003. An investigation of the failure mechanisms of thermoplastic composites at various rates of strain and temperatures. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Netangaheni, Phumudzo T AB - The focus of this project is on the deformation behaviour of thermoplastic composites. The materials used were polypropylene and polyamide resins with glass fibres and talc as fillers. These materials were provided by PLASTAMID (pty) ltd. The injection moulded specimens of polypropylene, polyamide 6-6, 30% talc filled polypropylene, 30% short glass fibre reinforced polypropylene and 30% short glass fibre reinforced polyamide 6-6 were tested in tension, flexure and impact (lzod, Charpy and drop-weight). Two different injection-moulding machines were used for specimen manufacture. These were an automated injection moulding machine simulating good control of processing conditions and a simple hand operated injection moulding machine simulating different processing and cooling (crystallisation) conditions. The mechanical tests were performed at different rates of strain and temperatures. The mechanical results show higher ductility of the unfilled polypropylene material. The strength and the elastic modulus of the materials are different for different materials. Addition of short glass fibres enhances the mechanical properties of polypropylene and polyamide 6-6. Talc fillers reduce the tensile, Izod and Charpy impact properties of polypropylene while the flexural and dropweight impact strength is increased. Optical and scanning electron microscopy were used to observe the microstructural features and deformation behaviour such as matrix plastic deformation, matrix crazing and tearing, fibre-matrix debonding, fibre fracture, fibre orientation and crack propagation. These deformation behaviours are influenced by the test conditions such as strain rate, temperature and the type of the test conducted. The deformation behaviour is also dependent on the constituents of the material. The mechanical test response together with the macro- and microscopic features observed on the fracture surfaces of tested specimens are evidence of the various mechanisms of failure that take place in different thermoplastic composites. The understanding of the mechanical response and the failure mechanisms of thermoplastic matrix composites is important in the design and processing stages. DA - 2003 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2003 T1 - An investigation of the failure mechanisms of thermoplastic composites at various rates of strain and temperatures TI - An investigation of the failure mechanisms of thermoplastic composites at various rates of strain and temperatures UR - http://hdl.handle.net/11427/8577 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/8577
dc.identifier.vancouvercitationNetangaheni PT. An investigation of the failure mechanisms of thermoplastic composites at various rates of strain and temperatures. [Thesis]. University of Cape Town ,Faculty of Engineering & the Built Environment ,Centre for Materials Engineering, 2003 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/8577en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentCentre for Materials Engineeringen_ZA
dc.publisher.facultyFaculty of Engineering and the Built Environment
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherMechanical Engineeringen_ZA
dc.titleAn investigation of the failure mechanisms of thermoplastic composites at various rates of strain and temperaturesen_ZA
dc.typeMaster Thesis
dc.type.qualificationlevelMasters
dc.type.qualificationnameMScen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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