Honeycomb sandwich structures (HSSs) with carbon fibre reinforced polymer (CFRP) composite face sheets are extensively used as light-weight structures in aerospace engineering due to their high strength-to-weight ratio and energy absorption properties. However, the composite face sheets are highly vulnerable to impact loads and cause damage to the structure based on the impact energy. This study investigates the structural response of HSS with CFRP face sheets under quasi-static indentation and a wide range of impact energy: low to high velocity impact. A finite-element model was developed and numerical simulations were carried out at various impact energies, thereby providing deeper insights into the impact dynamics and understanding various damage states such as dent, front face sheet perforation, core damage and rear face sheet penetration. The numerical simulation result was compared with the experimentally tested HSS using a single-stage gas gun under 53.6 J to validate the finite-element model in terms of deformation and damage status. A quasi-static indentation test was conducted and numerically predicted force data under impact test for the complete perforation case was compared to address the dependency of rate of loading. The carbon nanotube (CNT) with various weight percentages (wt%), such as 0.2, 0.4 and 0.6, was added to the matrix system through a vacuum assisted resin transfer technique and experiments were conducted at 79, 107 and 135 J. The impact resistance increases with CNT addition and hence no perforation was recorded for all the test cases of 0.6 wt% CNT addition. The influence of CNT addition on the damage area is more on the bottom face sheet and a 57% reduction in damage area was recorded for the case of 0.6 wt% CNT addition at 135 J impact energy when compared to the neat carbon/epoxy composite.

The present work discusses the bending, buckling and free vibration of natural fibre reinforced composite (NFC) plates initially. Numerical formulation is done based on higher order shear deformation theory and programming in Matlab environment is performed. The results for NFC plates are presented for several parametric variations. Finally, as an application of NFC panels, the cylindrical pressure vessel structure is analysed by considering flax-epoxy as inner laminate layers in combination with carbon-epoxy as outer laminate layers. The deformation and stress values are presented for various load conditions on the NFC pressure vessel.

Structural architecture plays a vital role in the design of solar powered aircraft. Wing analysis is critical as wings experience different loads and stresses. The objective of this work is to explore the use of renewable energy sources in aircraft technology in the form of solar-powered aircraft. The number of solar panels needed for a manned aircraft is determined based on the several solar factors. Thus this paper initially deals with the design of the wing structure for a solar powered two-seater aircraft. Also, the present work experimentally analyses the structural responses of a composite wing panel with and without the solar panel which makes this study significant.