No abstract

Automating the manufacturing process associated with composite components from prepreg presents new engineering challenges. To design, implement and operate machinery to handle and lay-up prepreg sheet material requires a clear understanding of the processes involved. Manipulation of sheet material is an integral part of the lay-up procedure. This paper presents the main automation issues concerning the production processes and defines a mathematical model for predicting the shape of prepreg sheets for the purposes of manipulation. This provides an aid towards the control of shape during the process of lay-up. Critical mould parameters, which determine prepreg sheet shape, are presented. Lay-up trajectories for a multi-arm robotic system have been derived, utilizing the models formulated. Practical trials with an existing multi-arm robotic system have proved satisfactory control of the process.

No abstract

Crashworthiness has recently become an increasingly important design consideration in the railway industry.Many old vehicles, however, do not meet today's safety standards and hence modifications to these structures can be made in order to improve their crash performance. Cost and ease of implementation are of particular concern in the design of such modifications. This paper discusses recent work on modifications to improve crashworthiness of a 45 year old carriage design, generally known as Mark 1 . The modifications were divided into three categories, namely: crush initiators, anti-overriding devices and shear-out components. Designs were carried out with the aid of dynamic finite element modelling tools and their outcomes validated with full-scale static and impact testing. The programme has shown that low-cost modifications to existing rolling stock are a viable method of improving their safety.

No abstract