Mechanical behaviour of glass and carbon fibre reinforced composites at varying strain rates

Review on the current practices and efforts towards pilot-scale production of metal-organic frameworks (MOFs)

Use of split Hopkinson pressure bar for testing off-axis composites

Constitutive model for high strain rate response of polymeric composites

A pulse-shaped split Hopkinson pressure bar (SHPB) was employed to determine the dynamic compressive mechanical responses and failure behaviors of a S-2 glass/SC15 composite along two perpendicular directions under valid dynamic testing conditions. The loading pulses in SHPB experiments were precisely controlled to ensure that the composite specimen deforms at a nearly constant strain rate under dynamically equilibrated stress during dynamic compression. Quasi-static experiments were conducted with an MTS and an Instron to study material rate sensitivity over a wider range. The compressive stress-strain behaviors along both directions were found to be strain-rate sensitive, but with different strain-rate sensitivities. A compressive constitutive model with strain-rate and damage effects was modified to accurately describe both quasi-static and dynamic compressive stress-strain behaviors of the composite material along the two perpendicular directions.

Quasi-Static and Dynamic Compressive Behaviors of a S-2 Glass/SC15 Composite

Dynamic compressive behaviour of unidirectional GFRP for various fibre orientations

Unidirectional glass-epoxy composite has been tested under dynamic compressive loading conditions to study the different modes of failure and characterize them fractographically. Specimens of six fibre orientationsθ = 0, 10, 30, 45, 60 and 90° with respect to the loading axis were loaded on Kolsky bars at an average strain rate of 265 sec−1. The failure occurs on three different types of plane such that the fibre direction is preserved in all cases. Type A planes are tensile split planes and 0° specimens fail only in this mode. 10, 30 and 45° specimens shear on Type B planes by the combined action of normal and shear stresses. 60° and 90° specimens also fail by shear by the combined action of normal and shear stresses but on different types of planes called Type C planes. In these specimens the normal of the failure plane is found to make an angle lying between 55° and 70° with respect to the loading axis. The fractographs indicate intense matrix deformation and breaking up of fibre-matrix bonds for shear failure and comparatively clean fracture surfaces for tensile failure.

Anita Garg

Papers

Dynamic compressive behaviour of unidirectional GFRP for various fibre orientations

Failure modes and fractographic study of glass−epoxy composite under dynamic compression