LOW VELOCITY IMPACT OF COMPOSITE CROP STRAW PANELS

Abstract The shock behaviour of crop straw reinforced composites with unsaturated polyester epoxy was studied. In this research an attempt has been made to design and manufacture protective composite vests for soldiers. The low velocity impact loading was generated by a drop weight impact machine with drop heights varying from 100 to 200 mm. The drop mass used in these experiments was 15 kg. The shock-absorbing capacity of the vests was found to be strongly affected by straw type, straw weight percentage per unit volume of composite panel (the permanent composite volume of the panel is equal to 434.2 cm3), and broken short rounded straight steel wire to straw weight ratio. This research concerns the evaluation of all the low velocity drop weight test parameters such as peak dynamic force, duration time, and impulse due to free falling of drop mass at different impact energies: 1.5, 2.25, and 3 J. In addition, indentation parameters such as contact force and absorbed energy could be evaluated. Mathematical models describing these parameters are presented in a form that can be easily predicted. The predicted shock-absorbing capacity shows good agreement with the experimental results. In addition, the optimum tailoring variables affecting the shock-absorbing performance of the composite vest system could be determined.