The Interlaminar Fracture Properties of Fibre Reinforced Thermoplastic Composites:The Efect of Processing Temperature and Time

An experimental study has been conducted to study the effect of processing temperature and dwell time on the critical energy release rate, Gc of unidirectional carbon fibre-reinforced poly ether imide (CF/PEI) under Mode II and Mixed-Mode I/II loading. Under Mode II loading, the value of GIIc, increased as a function of both processing temperature as well as with dwell time at the required temperature. A linear relationship was observed between the value of GIIc and the logarithm of the dwell time, t. Under Mixed-Mode loading conditions, the R-curves showed a continuous increase in the value of GI/IIC as a function of crack length, possibly due to the effect of fibre bridging. A comparison between the fracture toughness under Mode II shear loading and Mixed-Mode I/II loading indicated that Mode II loading yielded higher fracture energies for the same temperature and dwell time, possibly due to the occurrence of additional toughening mechanisms. The results suggest that the optimum processing temperature and dwell time for this material are 300°C and 60 minutes respectively. It is planned that these processing parameters will be employed in the repair of impact-damaged panels based on this thermoplastic material

Low-impulse blast behaviour of fibre-metal laminates

This paper presents three dimensional (3D) finite element (FE) models of the low-impulse localised blast loading response of fibre-metal laminates (FMLs) based on an 2024-O aluminium alloy and a woven glass-fibre/polypropylene composite (GFPP). A vectorized user material subroutine (VUMAT) is developed to define the mechanical constitutive behaviour and Hashin’s 3D failure criteria incorporating strain-rate effects in the GFPP. In order to apply localised blast loading, a user subroutine VDLOAD is used to model the pressure distribution over the exposed area of the plate. These subroutines are implemented into the commercial finite element code ABAQUS/Explicit to model the deformation and failure mechanisms in FMLs. The FE models consider FMLs based on various stacking configurations. Both the transient and permanent displacements of the laminates are investigated. Good correlation is obtained between the measured experimental and numerical displacements, the panel deformations and failure modes. By using the validated models, parametric studies can be carried out to optimise the blast resistance of FMLs based on a range of stacking sequences and layer thicknesses

Modelling of the low-impulse blast behaviour of fibre–metal laminates based on different aluminium alloys

A parametric study has been undertaken in order to investigate the influence of the properties of the aluminium alloy on the blast response of fibre–metal laminates (FMLs). The finite element (FE) models have been developed and validated using experimental data from tests on FMLs based on a 2024-O aluminium alloy and a woven glass–fibre/polypropylene composite (GFPP). A vectorized user material subroutine (VUMAT) was employed to define Hashin’s 3D rate-dependant damage constitutive model of the GFPP. Using the validated models, a parametric study has been carried out to investigate the blast resistance of FML panels based on the four aluminium alloys, namely 2024-O, 2024-T3, 6061-T6 and 7075-T6. It has been shown that there is an approximation linear relationship between the dimensionless back face displacement and the dimensionless impulse for all aluminium alloys investigated here. It has also shown that the residual displacement of back surface of the FML panels and the internal debonding are dependent on the yield strength of the aluminium alloy

PAREJA [Material gráfico]

ADQUIRIDA POR EL COLECCIONISTA EN LAS PALMAS G.C.FOTO DE SEÑORA SENTDA EN SILLA CON CABALLERO DE PIE A SU LADOCopia digital. Madrid : Ministerio de Educación, Cultura y Deporte. Subdirección General de Coordinación Bibliotecaria, 201

Morphing and control of a smart fibre metal laminate utilising plastic optical fibre sensor and Ni-Ti sheet

ICCM International Conferences on Composite Material