Paper number 429
|IMPACT RESPONSE OF CARBON FIBRE ROD, WITH AND WITHOUT A TENSIONED KEVLAR OVERWIND|
K.D. Potter, M.R. Wisnom
Department of Aerospace Engineering, Bristol University
Queen's Building, University Walk, Bristol, BS8 1TR. UK
|Summary||Sensitivity to impact plays a major role in limiting the design strains available in carbon fibre composite laminates and structures. Relatively low energy impacts can give rise to splitting in unidirectional composites, and delamination in multi-axial laminates, due to transverse and through thickness tensile stresses induced by the impact. This damage can then propagate under compressive loading leading to a great reduction in compressive strength. If the components could have imposed on them a transverse compressive pre-stress this would offset the effects of impact and lead to structures that are less sensitive to impact. The work reported here covers the imposition of such a pre-stress by overwinding structural elements with aramid fibre under considerable tension. The level of prestress in overwound rods has been investigated. Rod specimens have been impacted and tested after impact; a very substantial increase in compressive strength after impact has been observed.
||Keywords|| impact, compressive strength after impact, aramid fibres, overwinding.
Theme : Mechanical and Physical Properties ; Dynamic, Impact and crashworthiness
[ HOME ] [ BACK ]