The Experts below are selected from a list of 22026 Experts worldwide ranked by ideXlab platform
Wim Van Paepegem - One of the best experts on this subject based on the ideXlab platform.
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fatigue and post fatigue stress strain analysis of a 5 harness satin weave carbon fibre reinforced Composite
Composites Science and Technology, 2013Co-Authors: Subbareddy Daggumati, Joris Degrieck, Wim Van Paepegem, Ivan De Baere, Stepan Vladimirovitch Lomov, Ignace VerpoesAbstract:Abstract This paper presents the experimental fatigue damage analysis of a carbon-PPS (PolyPhenylene Sulphide) 5-harness satin weave Composite under tension–tension fatigue. Evolution of the longitudinal strain as well as the longitudinal stiffness of the Composite Specimen was monitored throughout the cyclic load process. During the fatigue test, instrumentation of the Composite structural response is categorized into two parts: (i) the first priority was to monitor the macro-scale structural response such as the increase in the longitudinal strain and hence decrease in the Composite longitudinal stiffness; (ii) the second priority was to capture the micro-scale damage events which are occurring in correlation with the observed fluctuations in the macro-scale structural response. Finally, comparison of the strength as well as stress–strain behaviour of the virgin Composite samples to the fatigue tested Specimens gives an overview of the effect of the induced fatigue damage on the strength and stiffness of the Composite Specimen.
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comparison of different techniques for strain monitoring of a biaxially loaded cruciform Specimen
Strain, 2011Co-Authors: Carla Ramault, Andreas Makris, D Van Hemelrijck, Ebrahim Lamkanfi, Wim Van PaepegemAbstract:: This study focuses on the evaluation of several strain measuring techniques for the instrumentation of an in-plane biaxial test bench. Strain gages, electronic speckle pattern interferometry (ESPI) and digital image correlation (DIC) were used combined or separately to measure the strains in the central gauge area of a biaxially loaded cruciform Composite Specimen. Applicability of the technique for this specific test and accuracy of the results are important parameters in the evaluation process of the different strain measuring techniques. The results of the three techniques are compared with the results obtained with a 3D finite element (FE) model. It is shown that DIC is the most promising technique because of its full-field character and ability to cope with vibrations of the test bench. The main drawback remains its incapability to correlate across discontinuities.
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effect of tab design on the strain distribution of a biaxially loaded cruciform Composite Specimen
17th International Conference on Composite Materials (ICCM-17), 2009Co-Authors: Carla Ramault, Andreas Makris, D Van Hemelrijck, Ebrahim Lamkanfi, Wim Van PaepegemAbstract:In general, Composite laminates are developing multiaxial stress states [1]. To get an accurate representation of the behaviour of Composite materials in a structure, tests under a uniaxial stress state do not satisfy. Therefore biaxial testing has to be considered. Despite the large demand for this experimental biaxial information there is little existing experimental capability to evaluate the multi-axial response of Composite materials [2].
Carla Ramault - One of the best experts on this subject based on the ideXlab platform.
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comparison of different techniques for strain monitoring of a biaxially loaded cruciform Specimen
Strain, 2011Co-Authors: Carla Ramault, Andreas Makris, D Van Hemelrijck, Ebrahim Lamkanfi, Wim Van PaepegemAbstract:: This study focuses on the evaluation of several strain measuring techniques for the instrumentation of an in-plane biaxial test bench. Strain gages, electronic speckle pattern interferometry (ESPI) and digital image correlation (DIC) were used combined or separately to measure the strains in the central gauge area of a biaxially loaded cruciform Composite Specimen. Applicability of the technique for this specific test and accuracy of the results are important parameters in the evaluation process of the different strain measuring techniques. The results of the three techniques are compared with the results obtained with a 3D finite element (FE) model. It is shown that DIC is the most promising technique because of its full-field character and ability to cope with vibrations of the test bench. The main drawback remains its incapability to correlate across discontinuities.
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effect of tab design on the strain distribution of a biaxially loaded cruciform Composite Specimen
17th International Conference on Composite Materials (ICCM-17), 2009Co-Authors: Carla Ramault, Andreas Makris, D Van Hemelrijck, Ebrahim Lamkanfi, Wim Van PaepegemAbstract:In general, Composite laminates are developing multiaxial stress states [1]. To get an accurate representation of the behaviour of Composite materials in a structure, tests under a uniaxial stress state do not satisfy. Therefore biaxial testing has to be considered. Despite the large demand for this experimental biaxial information there is little existing experimental capability to evaluate the multi-axial response of Composite materials [2].
A. Murphy - One of the best experts on this subject based on the ideXlab platform.
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Quantifying the Influence of Lightning Strike Pressure Loading on Composite Specimen Damage
Applied Composite Materials, 2019Co-Authors: P. Foster, G. Abdelal, A. MurphyAbstract:Experimental work has shown that a component of lightning strike damage is caused by a mechanical loading. As the profile of the pressure loading is unknown a number of authors propose different pressure loads, varying in form, application area and magnitude. The objective of this paper is to investigate the potential contribution of pressure loading to Composite Specimen damage. This is achieved through a simulation study using an established modelling approach for Composite damage prediction. The study examines the proposed shockwave loads from the literature. The simulation results are compared with measured test Specimen damage examining the form and scale of damage. The results for the first time quantify the significance of pressure loading, demonstrating that although a pressure load can cause damage consistent with that measured experimentally, it has a negligible contribution to the overall scale of damage. Moreover the requirements for a pressure to create the damage behaviours typically witnessed in testing requires that the pressure load be within a very precise window of magnitude and loading area.
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Sequential finite element modelling of lightning arc plasma and Composite Specimen thermal-electric damage
Computers & Structures, 2019Co-Authors: S.l.j. Millen, G. Abdelal, A. Murphy, Giuseppe CatalanottiAbstract:Abstract Highly complex phenomena such as lightning strikes require simulation methods capable of capturing many different physics. However, completing this in one simulation is not always desired or possible. In such instances there can be a need for a methodology to transfer loading boundary conditions from one simulation to the next while accounting for the characteristic form of the loading and the dissimilar domain and mesh geometries. Herein, the objective is to combine two models to enable the automatic sequential simulation of a lightning arc and a Composite test Specimen. The approach is developed using Finite Element models, with a Magnetohydrodynamics model representing the lightning plasma and a thermal-electric model representing the Specimen. The Specimen mesh and loading boundary conditions are automatically generated based on the predicted output of the preceding plasma model. The precision, run-time and flexibility of the proposed approach is demonstrated, with thermal damage predictions generated in approximately 33 h. Resulting from the integrated modelling capability is the first time prediction of damage representing the test electric boundary conditions rather than assumed Specimen boundary conditions (herein using test ‘Waveform B’).
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understanding how arc attachment behaviour influences the prediction of Composite Specimen thermal loading during an artificial lightning strike test
Composite Structures, 2018Co-Authors: P. Foster, G. Abdelal, A. MurphyAbstract:Abstract High speed image analysis of experimental lightning strike testing on Composite Specimens has demonstrated complex time-dependent arc attachment behaviour. To date simulation studies of lightning strike direct effects on Composite materials have overlooked or idealised the observed arc attachment behaviour. This is significant as these preceding studies have also demonstrated joule (resistive) heating is a major contributor to Composite material damage and thus the application of the current load is critically important. The objective of this paper is to quantify how arc attachment behaviour influences the prediction of Composite Specimen thermal loading during a simulated lightning strike test. This is achieved through a simulation study modelling experimental arc attachment behaviours referenced in the literature. The simulation results are compared with measured test Specimen damage. The results quantify for the first time the significance of arc attachment behaviour, demonstrating how realistic representation of arc expansion and arc movement can alter the predicted thermal loading and generate thermal damage patterns comparable to measured experimental damage.
B. Gangadhara Prusty - One of the best experts on this subject based on the ideXlab platform.
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Polymerisation Shrinkage Profiling of Dental Composites using Optical Fibre Sensing and their Correlation with Degree of Conversion and Curing Rate
Scientific Reports, 2019Co-Authors: Ginu Rajan, Raju Raju, Sagar Jinachandran, Paul Farrar, Jiangtao Xi, B. Gangadhara PrustyAbstract:Traditional polymerisation shrinkage (PS) measurement systems measure average PS of dental Composites, but the true local PS varies along the length and breadth of the Composite. The PS depends on the curing light intensity distribution, resultant degree of conversion (DOC) and the curing rate. In this paper, optical fibre Bragg grating (FBG) sensing based technology is used to measure the linear post-gel PS at multiple locations within dental Composite Specimens, and is correlated with DOC and curing rate. A commercial dental Composite is used, and its post-gel PS and DOC are mapped using embedded fibre Bragg grating sensors at different curing conditions. The distance between the curing lamp and the Composite Specimen is varied which resulted in different intensity distribution across the Specimen. The effect of curing light intensity distribution on PS, curing rate and DOC are investigated for demonstrating a relationship among them. It is demonstrated that FBG sensing method is an effective method to accurately profiling post-gel PS across the Specimen.
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Prediction of initiation and growth of single level delaminations in a transversely loaded Composite Specimen using fracture mechanics
International Journal of Fracture, 2008Co-Authors: Zoltan Mikulik, B. Gangadhara Prusty, Donald W Kelly, Rodney S ThomsonAbstract:The behaviour of a Composite test Specimen with an embedded delamination subjected to transverse tension has been investigated through experimental testing and finite element (FE) analyses. The testing program consisted of Specimens in two geometrical configurations; square and rectangular delamination. The initiation and growth of the delamination was numerically predicted by fracture mechanics. FE models were analysed with both MSC.Nastran and Abaqus FE codes. The MSC.Nastran model was used to calculate strain energy release rates employing a crack tip element methodology. The Abaqus model was evaluated using the virtual crack closure technique. Both approaches accurately predicted failure initiation locations as observed in the test Specimens. Failure loads were also well predicted. The mode mix at the crack tip in the proposed Specimen was found to be similar to the mode mix expected in a conventional in-plane compression Specimen.
Ebrahim Lamkanfi - One of the best experts on this subject based on the ideXlab platform.
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comparison of different techniques for strain monitoring of a biaxially loaded cruciform Specimen
Strain, 2011Co-Authors: Carla Ramault, Andreas Makris, D Van Hemelrijck, Ebrahim Lamkanfi, Wim Van PaepegemAbstract:: This study focuses on the evaluation of several strain measuring techniques for the instrumentation of an in-plane biaxial test bench. Strain gages, electronic speckle pattern interferometry (ESPI) and digital image correlation (DIC) were used combined or separately to measure the strains in the central gauge area of a biaxially loaded cruciform Composite Specimen. Applicability of the technique for this specific test and accuracy of the results are important parameters in the evaluation process of the different strain measuring techniques. The results of the three techniques are compared with the results obtained with a 3D finite element (FE) model. It is shown that DIC is the most promising technique because of its full-field character and ability to cope with vibrations of the test bench. The main drawback remains its incapability to correlate across discontinuities.
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effect of tab design on the strain distribution of a biaxially loaded cruciform Composite Specimen
17th International Conference on Composite Materials (ICCM-17), 2009Co-Authors: Carla Ramault, Andreas Makris, D Van Hemelrijck, Ebrahim Lamkanfi, Wim Van PaepegemAbstract:In general, Composite laminates are developing multiaxial stress states [1]. To get an accurate representation of the behaviour of Composite materials in a structure, tests under a uniaxial stress state do not satisfy. Therefore biaxial testing has to be considered. Despite the large demand for this experimental biaxial information there is little existing experimental capability to evaluate the multi-axial response of Composite materials [2].