The incremental contour method using asymmetric stiffness cuts

An incremental Contour Method (iCM) of residual stress measurement is proposed where residual stresses in the body of interest are sequentially reduced by successive contour cuts and the risk of stress re-distribution plastic- ity is mitigated or eliminated. The cutting-induced plasticity is known to cause significant inaccuracies when try- ing to measure the near-yield residual stresses using a conventional single cut contour method. The iCM procedure implements a new displacement data processing approach for the general case of sectioning at an ar- bitrary plane where the cut parts do not possess mirror-symmetric elastic stiffness. The basis for the new asymmetric stiffness data analysis approach is presented and the accuracy of the new method demonstrated using both numerical and experimental case studies

Delamination properties of laminated glass windows subject to blast loading

Delamination processes absorb significant amounts of energy in laminated glass windows when they are subjected to blast loads. Blast tests were performed previously and their results had been used to calculate the loads imposed on the support systems. In this research, the delamination process at realistic deformation rates was studied to understand the reaction force response obtained. Laboratory tensile tests were performed on pre-cracked laminated glass specimens to investigate their delamination behaviour. The experiments confirmed the presence of a plateau in the force-deflection graphs, suggesting that the delamination process absorbed significant energy. The experimental results were then employed to calibrate FEA models of the delamination process with the aim of estimating the delamination energy of the polyvinyl butyral (PVB) membrane and glass layers and its relationship with deformation speed. The delamination energies obtained through this research, if used with the appropriate PVB material model, are a valuable new tool new tool in the modelling and design of laminated glass façade structures