The Experts below are selected from a list of 192 Experts worldwide ranked by ideXlab platform
Olli Saarela - One of the best experts on this subject based on the ideXlab platform.
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influence of reinforcement positioning on tension tension fatigue performance of quasi unidirectional gfrp laminates made of stitched fabrics
Composites Part B-engineering, 2017Co-Authors: Samuli Korkiakoski, Essi Sarlin, Reija Suihkonen, Olli SaarelaAbstract:Abstract In quasi-unidirectional (quasi-UD) laminates reinforced with stitched non-crimp fabrics (NCF), axial fibre bundles in neighbouring fabrics can lie on top of each other or they may be overlapped. Also, the stitch phase can vary between the neighbouring fabrics. In this study, the effect of mutual location of axial fibre bundles and stitch phase difference on tension-tension fatigue performance of quasi-UD laminates reinforced by glass-fibres was experimentally investigated. Damage development and accumulation were monitored by photographing and thermal-imaging in the specimens' Gauge Section during the fatigue tests. Internal structure characterisation of the laminates based on micrographs was performed to find possible reasons that might affect the fatigue life. The study revealed that the stitch phase difference clearly affects the damage progression, fatigue life and the slope parameter of fitted S-N curves, but the effect of the mutual location of axial fibre bundles on these parameters is minor.
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influence of specimen type and reinforcement on measured tension tension fatigue life of unidirectional gfrp laminates
International Journal of Fatigue, 2016Co-Authors: Samuli Korkiakoski, Essi Sarlin, Povl Brondsted, Olli SaarelaAbstract:Abstract It is well known that standardised tension–tension fatigue test specimens of unidirectional (UD) glass-fibre-reinforced plastics (GFRP) laminates tend to fail at end tabs. The true fatigue life is then underestimated. The first objective of this study was to find for UD GFRP laminates a test specimen that fails in the Gauge Section. The second objective was to compare fatigue performance of two laminates, one having a newly developed UD powder-bound fabric as a reinforcement and the other having a quasi-UD stitched non-crimp fabric as a reinforcement. In the first phase, a rectangular specimen in accordance with the ISO 527-5 standard and two slightly different dog-bone shaped specimens were evaluated by means of finite element modelling. Subsequent comparative fatigue tests were performed for the laminates with the three specimen types. The results showed that the test specimen type has a significant effect on the failure mode and measured fatigue life of the laminates. A significantly higher fatigue life was measured for the laminate with the powder-bound fabric reinforcement when compared to the laminate with the stitched reinforcement.
Samuli Korkiakoski - One of the best experts on this subject based on the ideXlab platform.
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influence of reinforcement positioning on tension tension fatigue performance of quasi unidirectional gfrp laminates made of stitched fabrics
Composites Part B-engineering, 2017Co-Authors: Samuli Korkiakoski, Essi Sarlin, Reija Suihkonen, Olli SaarelaAbstract:Abstract In quasi-unidirectional (quasi-UD) laminates reinforced with stitched non-crimp fabrics (NCF), axial fibre bundles in neighbouring fabrics can lie on top of each other or they may be overlapped. Also, the stitch phase can vary between the neighbouring fabrics. In this study, the effect of mutual location of axial fibre bundles and stitch phase difference on tension-tension fatigue performance of quasi-UD laminates reinforced by glass-fibres was experimentally investigated. Damage development and accumulation were monitored by photographing and thermal-imaging in the specimens' Gauge Section during the fatigue tests. Internal structure characterisation of the laminates based on micrographs was performed to find possible reasons that might affect the fatigue life. The study revealed that the stitch phase difference clearly affects the damage progression, fatigue life and the slope parameter of fitted S-N curves, but the effect of the mutual location of axial fibre bundles on these parameters is minor.
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influence of specimen type and reinforcement on measured tension tension fatigue life of unidirectional gfrp laminates
International Journal of Fatigue, 2016Co-Authors: Samuli Korkiakoski, Essi Sarlin, Povl Brondsted, Olli SaarelaAbstract:Abstract It is well known that standardised tension–tension fatigue test specimens of unidirectional (UD) glass-fibre-reinforced plastics (GFRP) laminates tend to fail at end tabs. The true fatigue life is then underestimated. The first objective of this study was to find for UD GFRP laminates a test specimen that fails in the Gauge Section. The second objective was to compare fatigue performance of two laminates, one having a newly developed UD powder-bound fabric as a reinforcement and the other having a quasi-UD stitched non-crimp fabric as a reinforcement. In the first phase, a rectangular specimen in accordance with the ISO 527-5 standard and two slightly different dog-bone shaped specimens were evaluated by means of finite element modelling. Subsequent comparative fatigue tests were performed for the laminates with the three specimen types. The results showed that the test specimen type has a significant effect on the failure mode and measured fatigue life of the laminates. A significantly higher fatigue life was measured for the laminate with the powder-bound fabric reinforcement when compared to the laminate with the stitched reinforcement.
Z G Wang - One of the best experts on this subject based on the ideXlab platform.
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thermo mechanical aspects of adiabatic shear failure of am50 and ti6al4v alloys
Mechanics of Materials, 2008Co-Authors: D Rittel, Z G WangAbstract:Abstract The thermo-mechanical aspects of adiabatic shear band (ASB) formation are studied for two commercial alloys: Mg AM50 and Ti6Al4V. Tests are carried out on shear compression specimens (SCS). The evolution of the temperature in the deforming Gauge Section is monitored in real-time, using an array of high-speed infrared detectors synchronized with a Kolsky apparatus (split Hopkinson pressure bar). The evolution of the gage temperature is found to comprise three basic stages, in agreement with Marchand and Duffy’s simultaneous observations of mechanical data and Gauge deformation patterns (1988). The onset and full formation stages of ASB are identified by combining the collected thermal and mechanical data. Full development of the ASB is identified as the point at which the measured and calculated temperature curves intersect and diverge thereon. At that stage, the homogeneous strain assumption used in calculating the maximum temperature rise is no longer valid.
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thermo mechanical aspects of adiabatic shear failure of am50 and ti6al4v alloys
Volume 1: Advanced Energy Systems; Advanced and Digital Manufacturing; Advanced Materials; Aerospace, 2008Co-Authors: D Rittel, Z G WangAbstract:The thermo-mechanical aspects of adiabatic shear band (ASB) formation are studied for two commercial alloys: Mg AM50 and Ti6Al4V. Tests are carried out on shear compression specimens (SCS). The evolution of the temperature in the deforming Gauge Section is monitored in real time, using an array of high speed infrared detectors synchronized with a Kolsky apparatus (split Hopkinson pressure bar). The evolution of the gage temperature is found to comprise 3 basic stages, in agreement with Marchand and Duffy’s simultaneous observations of mechanical data and Gauge deformation patterns (1988). The onset and full formation stages of ASB are identified by combining the collected thermal and mechanical data. Full development of the ASB is identified as the point at which the measured and calculated temperature curves intersect and diverge thereon. At that stage, the homogeneous strain assumption used in calculating the maximum temperature rise is no longer valid.
Essi Sarlin - One of the best experts on this subject based on the ideXlab platform.
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influence of reinforcement positioning on tension tension fatigue performance of quasi unidirectional gfrp laminates made of stitched fabrics
Composites Part B-engineering, 2017Co-Authors: Samuli Korkiakoski, Essi Sarlin, Reija Suihkonen, Olli SaarelaAbstract:Abstract In quasi-unidirectional (quasi-UD) laminates reinforced with stitched non-crimp fabrics (NCF), axial fibre bundles in neighbouring fabrics can lie on top of each other or they may be overlapped. Also, the stitch phase can vary between the neighbouring fabrics. In this study, the effect of mutual location of axial fibre bundles and stitch phase difference on tension-tension fatigue performance of quasi-UD laminates reinforced by glass-fibres was experimentally investigated. Damage development and accumulation were monitored by photographing and thermal-imaging in the specimens' Gauge Section during the fatigue tests. Internal structure characterisation of the laminates based on micrographs was performed to find possible reasons that might affect the fatigue life. The study revealed that the stitch phase difference clearly affects the damage progression, fatigue life and the slope parameter of fitted S-N curves, but the effect of the mutual location of axial fibre bundles on these parameters is minor.
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influence of specimen type and reinforcement on measured tension tension fatigue life of unidirectional gfrp laminates
International Journal of Fatigue, 2016Co-Authors: Samuli Korkiakoski, Essi Sarlin, Povl Brondsted, Olli SaarelaAbstract:Abstract It is well known that standardised tension–tension fatigue test specimens of unidirectional (UD) glass-fibre-reinforced plastics (GFRP) laminates tend to fail at end tabs. The true fatigue life is then underestimated. The first objective of this study was to find for UD GFRP laminates a test specimen that fails in the Gauge Section. The second objective was to compare fatigue performance of two laminates, one having a newly developed UD powder-bound fabric as a reinforcement and the other having a quasi-UD stitched non-crimp fabric as a reinforcement. In the first phase, a rectangular specimen in accordance with the ISO 527-5 standard and two slightly different dog-bone shaped specimens were evaluated by means of finite element modelling. Subsequent comparative fatigue tests were performed for the laminates with the three specimen types. The results showed that the test specimen type has a significant effect on the failure mode and measured fatigue life of the laminates. A significantly higher fatigue life was measured for the laminate with the powder-bound fabric reinforcement when compared to the laminate with the stitched reinforcement.
D Rittel - One of the best experts on this subject based on the ideXlab platform.
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thermo mechanical aspects of adiabatic shear failure of am50 and ti6al4v alloys
Mechanics of Materials, 2008Co-Authors: D Rittel, Z G WangAbstract:Abstract The thermo-mechanical aspects of adiabatic shear band (ASB) formation are studied for two commercial alloys: Mg AM50 and Ti6Al4V. Tests are carried out on shear compression specimens (SCS). The evolution of the temperature in the deforming Gauge Section is monitored in real-time, using an array of high-speed infrared detectors synchronized with a Kolsky apparatus (split Hopkinson pressure bar). The evolution of the gage temperature is found to comprise three basic stages, in agreement with Marchand and Duffy’s simultaneous observations of mechanical data and Gauge deformation patterns (1988). The onset and full formation stages of ASB are identified by combining the collected thermal and mechanical data. Full development of the ASB is identified as the point at which the measured and calculated temperature curves intersect and diverge thereon. At that stage, the homogeneous strain assumption used in calculating the maximum temperature rise is no longer valid.
-
thermo mechanical aspects of adiabatic shear failure of am50 and ti6al4v alloys
Volume 1: Advanced Energy Systems; Advanced and Digital Manufacturing; Advanced Materials; Aerospace, 2008Co-Authors: D Rittel, Z G WangAbstract:The thermo-mechanical aspects of adiabatic shear band (ASB) formation are studied for two commercial alloys: Mg AM50 and Ti6Al4V. Tests are carried out on shear compression specimens (SCS). The evolution of the temperature in the deforming Gauge Section is monitored in real time, using an array of high speed infrared detectors synchronized with a Kolsky apparatus (split Hopkinson pressure bar). The evolution of the gage temperature is found to comprise 3 basic stages, in agreement with Marchand and Duffy’s simultaneous observations of mechanical data and Gauge deformation patterns (1988). The onset and full formation stages of ASB are identified by combining the collected thermal and mechanical data. Full development of the ASB is identified as the point at which the measured and calculated temperature curves intersect and diverge thereon. At that stage, the homogeneous strain assumption used in calculating the maximum temperature rise is no longer valid.
