Publications
217 results found
Pinho ST, Robinson P, Iannucci L, 2009, Developing a four point bend specimen to measure the mode I intralaminar fracture toughness of unidirectional laminated composites, COMPOSITES SCIENCE AND TECHNOLOGY, Vol: 69, Pages: 1303-1309, ISSN: 0266-3538
- Author Web Link
- Open Access Link
- Cite
- Citations: 49
Pimenta S, Gutkin R, Pinho ST, et al., 2009, A micromechanical model for kink-band formation: Part II-Analytical modelling, COMPOSITES SCIENCE AND TECHNOLOGY, Vol: 69, Pages: 956-964, ISSN: 0266-3538
- Author Web Link
- Open Access Link
- Cite
- Citations: 73
Galvanetto U, Robinson P, Cerioni A, et al., 2009, Assessment of the performance of two formulations of interface elements for the simulation of fatigue induced delamination
Recently interface elements have been used in the simulation of fatigue induced crack propagation. This work presents a one degree of freedom mathematical model which can be used to assess systematically the performance of different interface element formulations in an efficient and rational way.
Pimenta S, Pinho ST, Robinson P, 2009, Experimental study on the mechanical performance of recycled CFRP
The mechanical behaviour of a recycled CFRP (rCFRP), with fibres reclaimed by pyrolysis and manufactured via resin infusion of recycled-fibre mats, is studied. The mechanical properties are characterised, demonstrating that rCFRP can replace GFRP. The rCFRP failure modes in tension and compression are also investigated, at the microcopic scale.
Gutkin R, Pinho ST, Robinson P, et al., 2009, Investigation of kink-band formation under biaxial stress state
This paper investigates longitudinal compressive failure. Two failure modes were observed experimentally for pure longitudinal compression: shear-driven fibre compressive failure and kink-band formation. In a micromechanical numerical study, failure envelopes for combined longitudinal compression and in-plane shear were predicted.
McCarroll CA, Robinson P, Pinho ST, et al., 2009, High rate fractue toughness test design for tensile fibre failure modes
The compact tension specimen has been investigated numerically for the measurement of Mode I fracture toughness associated with fibre tensile failure,GIc, at crack speeds of the order of 200 m/s. This paper develops a load-independent data reduction scheme for analysing such tests using the compressive strain measured at the back edge of the specimen.
Pinho ST, Robinson P, Schuecker C, et al., 2009, Pressure-dependent constitutive and failure model for laminated composites
This paper presents a non-linear, pressure-dependent, three dimensional constitutive law and associated failure criteria for laminated composites with UD plies. The failure criteria result from a physical model for each failure mode. In-situ strengths are used for matrix failure and fibre kinking. The model is validated against experimental data.
Carvalho NV, Pinho ST, Robinson P, 2009, Compressive failure of 2D woven composites
This paper presents experimental and numerical research on the compressive failure of orthogonal 2-D woven composites with different stacking emphasizing the role of the interlacing region of tows. Resulting optical micrographs demonstrate the influence of the support of adjacent layers on the sequence of events leading to failure of woven composites.
Robinson P, 2009, A self-indicating mode I interlaminar toughness test
This paper reports on the development of a Mode I interlaminar test which has been designed to indicate the crack position on the load-displacement curve so avoiding the requirement to monitor the crack length during the test. Results of the self-indicating test show good agreement with the conventional Mode I test method.
Laffan MJ, Pinho ST, Robinson P, et al., 2009, Fracture toughness measurement for mode i fibre tensile failure in FRP
The compact tension specimen was used to measure the fracture toughness of the fibre tensile failure mode, in UD plies. An optimal data reduction scheme was identified and used to investigate specimen geometrical and lay-up effects. It was demonstrated that is not simply a material property, but dependent upon specimen lay-up.
Greenhalgh ES, Rogers CE, Robinson P, 2009, Fractographic Observations on Delamination Growth and the Subsequent Migration Mechanisms Through the Laminate, Composites Science and Technology, Vol: 69, Pages: 2345-2351, ISSN: 0266-3538
This paper describes fractographic observations from the detailed examination of delamination fracture surfaces and offers an interpretation of the key growth mechanisms. Firstly, the relationship between toughness, delamination failure criteria and fracture morphology is presented and the influence of cusp formation and deformation on toughness is discussed. Observations regarding delaminations migrating through the lamina at multidirectional ply interfaces are then discussed. It is demonstrated how this migration process can be avoided in fracture toughness coupons and consequently the toughness of multidirectional ply interfaces can be characterised. The influence of migration on delamination growth from embedded defects in laminates under compression is presented, and these results are extended to demonstrate how migration influences damage growth in structures. The paper concludes by making recommendations for realistic modelling of migration, and suggests how it can be exploited in damage tolerant structural design.
Guiamatsia I, Falzon BG, Davies GAO, et al., 2008, Improving Composite Damage Modelling through Automatic Placement of Cohesive Elements, 49th AIAA SDM conference
Raimondo L, Iannucci L, Robinson P, et al., 2008, A Numerical Material Model for Predicting the High Velocity Impact Behaviour of Polymer Composites, 1st ECCOMAS Thematic Conference on Mechanical Response of Composites, Publisher: SPRINGER-VERLAG BERLIN, Pages: 161-177
- Author Web Link
- Cite
- Citations: 8
López-Armas CA, Galvanetto U, Robinson P, 2007, A simple model for the evaluation of fatigue degradation laws for interface elements
A simple model that represents interface elements subjected to fatigue loading is proposed and used to evaluate three different constitutive laws as well as three different damage definitions. The three constitutive laws are bilinear, third-order polynomial and linear-polynomial while the damage definitions are based on the degradation of stiffness and the energy consumed. The behaviour of the constitutive laws and damage formulations has been found to be similar but with some variations in their sensitivity to the size of the elements and to the number of cycles applied in each load step. The results confirm that the more accurate results are found for smaller values of these two variables.
Gill AF, Robinson P, Hitchings D, 2007, Measurement of damage progression in open hole tension tests
To be completely confident in the accuracy of a damage propagation model for composite structures it is necessary to validate the predicted behaviour against experimental results. It is therefore desirable to develop techniques for identifying and tracking damage as it progresses through laminated composite specimens. This has been achieved for open hole tension (OHT) coupons by employing a combination of full strain field measurement, acoustic emission, microscopy and ultrasound Cscan techniques. Using this method, it has been possible to locate and distinguish damage by identifying areas that exhibit sudden increases in strain resulting from changes in laminate compliance. Correlation with recorded acoustic emission events and post-test microscopy was used to confirm that damage had occurred. The work described in this paper provides a means for validating predictive models as well as helping to develop a better understanding of damage mechanisms.
Raimondo L, Iannucci L, Robinson P, et al., 2007, Predicting the dynamic behaviour of polymer composites
This paper describes experimental and numerical research activities aimed at the development, implementation into an explicit FE code, and validation of a state-of-the-art composite material model for dynamic failure. The developed material model, which can predict the behaviour of UD Carbon Fibre Reinforced Polymer (CFRP) composites, is implemented into LS-DYNA3D for solid brick elements with one integration point. Though the developed model has wide applicability, this paper focuses on aspects related to validation against composites ballistic data.
Gill AF, Robinson P, Pinho S, et al., 2007, Effect of RTM defects on mode I & II delamination behaviour of 5HS woven composites
Composites produced by resin infusion techniques will inevitably suffer from variation in resin distribution due to imprecise fibre placement and distortion of the preform during mould closure and infusion. This paper describes an investigation into the effect of variations in fibre volume fraction (FVF) on mode I and mode II delamination behaviour for 5 harness satin (5HS) woven carbon-fibre/epoxy resin composites manufactured by resin transfer moulding (RTM). Additionally, the effect of satin face tow orientation on interlaminar toughness was investigated.
Robinson P, Message S, 2007, Interface effects in mode II interlaminar toughness testing of unidirectional composites
This paper reports on an investigation of the influence of friction and nesting on the Mode II toughness of unidirectional composites measured using the 4-point loaded end-notched flexure test. A special modification of this test configuration was developed which enabled the compressive force acting across the sliding interface to be reduced to zero. The results indicated that friction has a fairly small effect on the measured toughness. Specimens with different nesting characteristics were produced by using different crack starter methods. It was found that greater nesting resulted in significantly higher Mode II toughnesses, particularly at initiation. Further investigation revealed that the sliding surfaces separate in an opening mode and that the amount of separation increases with the magnitude of the nesting.
Dogra J, Hodgkinson JM, Robinson P, et al., 2007, Development of a compression test for thick composite laminates: finite element analysis, 16th International Conference on Composite Materials
Greenhalgh ES, Rogers CE, Robinson P, 2007, Fractographic Observations of Delamination Growth Mechanisms, 16th International Conference on Composite Materials
Oakeshott JL, Iannucci L, Robinson P, 2007, Development of a representative unit cell model for bi-axial NCF composites, JOURNAL OF COMPOSITE MATERIALS, Vol: 41, Pages: 801-835, ISSN: 0021-9983
- Author Web Link
- Cite
- Citations: 8
Gill AF, Robinson P, Pinho S, et al., 2007, Effect of RTM defects on mode I & II delamination behaviour of 5HS woven composites
Composites produced by resin infusion techniques will inevitably suffer from variation in resin distribution due to imprecise fibre placement and distortion of the preform during mould closure and infusion. This paper describes an investigation into the effect of variations in fibre volume fraction (FVF) on mode I and mode II delamination behaviour for 5 harness satin (5HS) woven carbon-fibre/epoxy resin composites manufactured by resin transfer moulding (RTM). Additionally, the effect of satin face tow orientation on interlaminar toughness was investigated.
Raimondo L, Iannucci L, Robinson P, et al., 2007, Predicting the dynamic behaviour of polymer composites
This paper describes experimental and numerical research activities aimed at the development, implementation into an explicit FE code, and validation of a state-of-the-art composite material model for dynamic failure. The developed material model, which can predict the behaviour of UD Carbon Fibre Reinforced Polymer (CFRP) composites, is implemented into LS-DYNA3D for solid brick elements with one integration point. Though the developed model has wide applicability, this paper focuses on aspects related to validation against composites ballistic data.
López-Armas CA, Galvanetto U, Robinson P, 2007, A simple model for the evaluation of fatigue degradation laws for interface elements
A simple model that represents interface elements subjected to fatigue loading is proposed and used to evaluate three different constitutive laws as well as three different damage definitions. The three constitutive laws are bilinear, third-order polynomial and linear-polynomial while the damage definitions are based on the degradation of stiffness and the energy consumed. The behaviour of the constitutive laws and damage formulations has been found to be similar but with some variations in their sensitivity to the size of the elements and to the number of cycles applied in each load step. The results confirm that the more accurate results are found for smaller values of these two variables.
Gill AF, Robinson P, Hitchings D, 2007, Measurement of damage progression in open hole tension tests
To be completely confident in the accuracy of a damage propagation model for composite structures it is necessary to validate the predicted behaviour against experimental results. It is therefore desirable to develop techniques for identifying and tracking damage as it progresses through laminated composite specimens. This has been achieved for open hole tension (OHT) coupons by employing a combination of full strain field measurement, acoustic emission, microscopy and ultrasound Cscan techniques. Using this method, it has been possible to locate and distinguish damage by identifying areas that exhibit sudden increases in strain resulting from changes in laminate compliance. Correlation with recorded acoustic emission events and post-test microscopy was used to confirm that damage had occurred. The work described in this paper provides a means for validating predictive models as well as helping to develop a better understanding of damage mechanisms.
Dogra J, Hodgkinson JM, Robinson P, et al., 2007, Development of a compression test for thick composite laminates: Finite element analysis
Finite element stress analyses have been made for composite laminates loaded in compression with a thickness of 2 mm and 10 mm, where the main parts of the fixture have also been modelled. Different designs have been investigated and the results are compared with a 2 mm thick specimen. Results for a reverse chamfer design and width waisted design for two different profiles are presented for a 10 mm thick specimen. A width waisted design has shown to significantly reduce stress concentrations in the fibre direction. A profile defined by a cubic equation offers the most promising results. The effect of including a model of the fixture grip in the transverse fibre direction on the specimen stress distribution is also considered for a 10 mm thick specimen. This has shown to increase the longitudinal stress concentrations in the specimen.
Greenhalgh ES, Rogers C, Robinson P, 2007, Fractographic observations of delamination growth mechanisms
This paper provides an overview of fractographic observations from the detailed examination of delamination fracture surfaces. Firstly, the relationship between toughness, delamination failure criteria and fracture morphology is presented and the influence on toughness of cusp formation and deformation is discussed. Recent research is presented on macromodelling of cusps using shear loaded PVC foam. Delamination migration at multidirectional ply interfaces is then discussed and the mechanism by which delaminations migrate is presented. It is demonstrated how migration can be avoided in fracture toughness coupons and consequently the toughness of multidirectional ply interfaces can be characterised. The influence of migration on delamination growth from embedded defects in laminates under compression is presented, and these results are extended to demonstrate how migration influences damage growth in structures. The paper concludes by making recommendations for realistic modelling of migration, and suggests how it can be exploited in damage tolerant structural design.
Robinson P, Message S, 2007, Interface effects in mode II interlaminar toughness testing of unidirectional composites
This paper reports on an investigation of the influence of friction and nesting on the Mode II toughness of unidirectional composites measured using the 4-point loaded end-notched flexure test. A special modification of this test configuration was developed which enabled the compressive force acting across the sliding interface to be reduced to zero. The results indicated that friction has a fairly small effect on the measured toughness. Specimens with different nesting characteristics were produced by using different crack starter methods. It was found that greater nesting resulted in significantly higher Mode II toughnesses, particularly at initiation. Further investigation revealed that the sliding surfaces separate in an opening mode and that the amount of separation increases with the magnitude of the nesting.
Narita Y, Robinson P, 2006, Maximizing the fundamental frequency of laminated cylindrical panels using layerwise optimization, INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES, Vol: 48, Pages: 1516-1524, ISSN: 0020-7403
- Author Web Link
- Cite
- Citations: 41
Munoz JJ, Galvanetto U, Robinson P, 2006, On the numerical simulation of fatigue driven delamination with interface elements, 3rd International Conference on Fatigue of Composites (ICFC3), Publisher: ELSEVIER SCI LTD, Pages: 1136-1146, ISSN: 0142-1123
- Author Web Link
- Cite
- Citations: 63
This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.