Analysis of inelastic buckling of rectangular plates with a free edge using polynomial deflection functions

The inelastic buckling behaviour of different rectangular thin isotropic plates having a free edge is studied. Various combinations of boundary conditions are subject to in-plane uniaxial compression and each rectangular plate is bounded by an unloaded free edge. The characteristic deflection function of each plate is formulated using a polynomial function in form of Taylor–Maclaurin series. A deformation plasticity approach is adopted and the buckling load equation is modified using a work principle technique. Buckling coefficients of the plates are calculated for various aspect ratios and moduli ratios. Findings obtained from the investigation are found to reasonably agree with data published in the literature.

3D Imaging of Indentation Damage in Bone

Bone is a complex material comprising high stiffness, but brittle, crystalline bio-apatite combined with compliant, but tough, collagen fibres. It can accommodate significant deformation, and the bone microstructure inhibits crack propagation such that micro-cracks can be quickly repaired. Catastrophic failure (bone fracture) is a major cause of morbidity, particularly in aging populations, either through a succession of small fractures or because a traumatic event is sufficiently large to overcome the individual crack blunting/shielding mechanisms. Indentation methods provide a convenient way of characterising the mechanical properties of bone. It is important to be able to visualise the interactions between the bone microstructure and the damage events in three dimensions (3D) to better understand the nature of the damage processes that occur in bone and the relevance of indentation tests in evaluating bone resilience and strength. For the first time, time-lapse laboratory X-ray computed tomography (CT) has been used to establish a time-evolving picture of bone deformation/plasticity and cracking. The sites of both crack initiation and termination as well as the interconnectivity of cracks and pores have been visualised and identified in 2D and 3D.