The use of computational mechanics to simulate structural and fluid behaviour and to assess and solve civil engineering problems is growing, and industrial applications are becoming increasingly automated and integrated with so-called design engines for code of practice checking. There is a danger however, that in applying increasingly automated processes, engineers can avoid truly understanding the problem and, therefore, the ability to be innovative and creative in design could be weakened, or designs becoming increasingly predetermined in form. It is fair to say that the application of computational mechanics in most cases plays no part in helping to conceptualise an engineering design, but is enormously valuable in proving an idea, refinement, solving combined problems and in effect offering a virtual prototype for specific behaviour. A fundamental understanding of the basics and the ability to be imaginative is still required to produce innovative and elegant design. It is now increasingly important, because the choice exists, to recognise the stages where hand calculations, semi empirical solutions, and simple and complex computational approaches are most usefully applied. With issue 3 of Engineering and Computational Mechanics, papers using both semi-empirical and detailed numerical approaches are presented, and as with previous issues, are on both solid and fluid mechanics.
The briefing by Alistair Borthwick focuses on the history of research into engineering fluid mechanics at the University of Oxford. The second paper, by Vardy, is concerned with the generation and alleviation of sonic booms caused by trains travelling through railway tunnels and presents design expressions so that their amplitude and disturbing effects can be estimated. It is targeted primarily at designers wishing to make initial assesments without any need for specialist software or specialist expertise and for cases where disturbance is calculated to be excessive; it describes the potential effectiveness of some remedial measures.
In the third paper, Kuang presents a semi-analytical method which will be of interest to designers and assessors of plate-and-grid structures such as waffle slabs, ribbed plates and slab-girder bridges. Developed for vertical loads, the author suggests the principal benefit over equivalent finite-element analyses is in the reduced time required to calculate bending and deflection results. Consequently, this approach should be of particular interest to engineers in conceptual stages of design as well as for rapid structural assessment.
