Among the various forms of material damage, delamination due to drilling is one of the major concerns in machining a composite laminate. The thrust force has been cited as the primary cause of the delamination. The analysis for multidirectional composite laminates is based on linear elastic fracture mechanics (LEFM), classical bending plate theory and the mechanics of composites. This paper presents a general closed-form mechanical model for predicting the critical thrust force at which delamination is initiated at different ply locations. Good correlation is observed between the model and the experimental results.

The aims of this study were to investigate suitable LED lighting conditions for viewing fine art paintings in a museum environment and to test Kruithof's rule that defines pleasant lighting in terms of correlated colour temperature (CCT) and illuminance. The experiment was conducted in a room designed to simulate the exhibition of real paintings in museums. Twenty-four observers of different gender and educational background participated to evaluate oil and gouache paintings under different lighting conditions. Each painting was assessed via 14 word pairs using the categorical judgment method. The results showed that illuminance had a larger impact than CCT on visual perception, and three factors dominate visual perceptions: Comfort, Vividness and Definition. The present results only partially agreed with Kruithof's rule. A comfort zone of illuminance and CCT for paintings in museums has been developed.

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An experiment has been carried out to investigate the effect of lighting on the perception of atmosphere in a living room, using three types of light sources: halogen, fluorescent and LED lamps. In a psychophysical experiment, 29 native Chinese observers assessed eight lighting conditions having different luminances and correlated colour temperatures. For each condition, 71 scales were employed using the categorical judgment method. Factor analysis identified two underlying dimensions: liveliness and cosiness. This agrees with those found by Vogels who used Dutch observers to assess atmosphere perception. Both observer groups also agreed that an increase of luminance would make the room more lively. However, there were also some disagreements such as a higher CCT source would make the room more lively for Chinese observers but less lively for Dutch observers.