Structural engineers are primarily concerned with the design and assessment of load bearing structures. Of paramount interest is ensuring sufficient structural capacity (strength) to withstand the loads (demand). It is also important, in an increasingly energy-conscious world, not to waste material unnecessarily. In the design of reinforced concrete (RC) slabs, the engineer may use limit analysis to assess the flexural strength of a design but, until recently, this has involved a laborious hand calculation using either the yield line technique or the strip method. …
Author Archives : Edward Maunder, MA, DIC, Ph.D.
Edward Maunder, MA, DIC, Ph.D., FIStructE, is a consultant to Ramsay Maunder Associates and an honorary Fellow of the University of Exeter in the UK. He is a member of the Academic Qualifications Panel of the Institution of Structural Engineers. He acts a reviewer for several international journals, such as the International Journal for Numerical Methods in Engineering, Computers and Structures, and Engineering Structures. He can be contacted at e.a.w.maunder@exeter.co.uk.
Saint Venant established his theory of torsion (1853) by assuming axially invariant modes of tangential and axial (warping) displacements. In conjunction with known static boundary conditions, the equations of elasticity were satisfied leading to an exact solution for pure torsion. His theory assumes free warping displacement and, when this is restrained, the torsional stiffness is increased depending on the cross-sectional shape. …
The authors recently conducted a study into the elastic behaviour of thin (Kirchhoff) plates using commercial finite element (FE) software. In attempting to verify the FE solution, it was compared to results presented in Timoshenko’s text and a significant difference was observed. This article presents the work conducted to uncover the reason for this difference and reveals an error (probably typographical) in the text. The source of the error is identified and it is demonstrated how such errors might propagate into other texts on the subject of plates. The significance of the error to the practising engineer is also discussed. …
At a recent workshop, organized by the University of Sheffield in association with LimitState and held at the IStructE Headquarters in London, the authors of this article presented new computational tools for the limit analysis of reinforced concrete (RC) slabs. The workshop was attended by practising engineers from different fields, including those involved with the design of RC slabs and those with an interest in the assessment of existing RC slabs for changing service loads. …