Boeing (United Kingdom)

Squeeze Film Damping (SFD) is used extensively in vibration control, particularly in rotor dynamics. In the aeronautical and astronautical industries, aircraft and spacecraft components are commonly produced in shell form to keep their mass to a minimum. When machining shell components, it is found that large vibrations are produced which can be detrimental to the accuracy of the machining process or the shell components themselves. In this paper SFD is analysed based on Reynolds theory and the damping coefficient of a spring-mass system with SFD is formulized. SFD is successfully applied in shell machining with a bottom thickness 0.3 mm in an area of 65 × 65 mm2.

Compressive failure behavior of composite laminates containing open hole was investigated systematically through the mechanical tests and damage monitoring studies of the multidirectional composite laminates (T300/924C [45/-45/0/90]3s and T800/924C [45/0/-45/90]3s ). Fibre microbuckling in the 0( plies, surrounded by delamination, occurred in the vicinity of the hole prior to catastrophic fracture. The microbuckling, which leads to extensive in and out-of-plane fibre kinking, extends stably under increasing load before becoming unstable at a critical length of 2-3mm (depends on the specimen geometry) along the specimen width. The effect of a single 3mm diameter hole in a 30mm wide plate is to reduce the gross section strengths by about 40% and 38%, respectively when compared to the unnotched failure strength. The failure strengths were predicted successfully the open hole strength for both materials, less than 7% difference when compared to the measured experimental results.

This research presents findings from two studies conducted by the Universities of Cranfield and Sheffield, which investigated two complimentary, but unrelated, areas of research – manufacturing cladistics, an evolutionary classification scheme from the biological sciences, and evolutionary systems modelling, from the physical sciences. Using this new evolutionary framework, designed to model through simulation the evolution of manufacturing form, new structural organizations were explored. A second study is presented that explores the diversity of management decision-making and the potential consequences on the evolution of manufacturing form. This research compares and contrasts the different opinions of decision-makers. The results, in terms of the evolutionary trajectories that the firm may take, provide interesting insights into the consequences of decision-making of different managers that inevitably base their decisions on different information, values and beliefs. The aim of this and related research is to develop a user-friendly decision-support tool for management.