Analysis of symmetric and asymmetric glass fiber reinforced plastic laminates subjected to low-velocity impact

Abstract

Low-velocity impact induced damage in symmetric and asymmetric laminates is analyzed. A generalized lay-up sequence is proposed for asymmetric laminate. Asymmetric laminate fabricated according to the proposed lay-up sequence have its stiffness characteristic almost identical to those of a symmetric laminates. Proposed lay-up sequence provides a laminate which have zero bending-extension coupling and behaves as quasi-isotropic laminate. A cylindrical impactor with hemispherical nose having mass 5.23 kg is impacted with a velocity of 3 ms⁻¹, 4 ms⁻¹, and 6 ms⁻¹. Damage pattern and energy–time relation of proposed asymmetric laminate are compared with symmetric laminate having similar stiffness matrices. Energy absorbed by proposed quasi-isotropic asymmetric and symmetric laminate is also compared with laminate of different stacking sequence proposed by various researchers. Numerical analysis is done by commercially available software LS-DYNA.