Low-Velocity Impact Response of Hybrid CNTs Reinforced Conical Shell Under Hygrothermal Conditions

In the present analysis, low-velocity impact investigation of a hybrid CNT-fibernano composite twisted conical shell is carried out under varying moisture and thermal environment using finite element methodology. The impact is caused by a spherical impactor at the centre of the panel. The twisted conical shell made of CNT-fibernano composite with cantilever boundary condition can be idealized as turbo machinery blade. The first order shear deformation theory (FSDT) is used to compute the strains and an eight noded isoparametric shell element, which comprises of 5 degree of freedom per node, is used to discretize the panel. The modified Hertzian contact law is used to measure the contact force due the impact between the impactor and the panel. Using Lagrange's equation of motion, dynamic equation is formulated, considering cantilever boundary condition. The solution of the dynamic equation is obtained by Newmark's time integration algorithm. The finite element programme is developed and validated with the existing literature to analyse the effect of weight fraction of CNTs, twist angle of the conical shell and the effect of velocity of impact on the contact force, impactor displacement, initial velocity of impactor and indentation. Numerical results reveal that by increasing the weight fraction of CNT, increases the stiffness of the panel thereby the contact forces. However, by increasing the temperature and moisture, the contact force decreases as a result of decrease in stiffness of the structure. The twist angle has striking effects in the contact force histories.