Sandwich panels fabricated by attaching facing plates to a folded-plate, directional stiffening core and penetrated by holes present a difficult analytical problem which can be solved by the use of large finite element packages. K.H. Tan and Professor P. Montague
Dr. D. Johnson (M) (Nottingham Polytechnic) Dr. Creed’s emphasis on the physical operations involved in moment distribution as illustrated by the calculation of rotations and, hence, deflected shapes is an approach which has been adopted by at least one recent text. There is also certainly a school of thought which feels that ‘topics like moment distribution are now anachronistic and can go’, in which context it is interesting to observe that the survey contained in the Institution report ‘Qualitative analysis of structures’ found that moment distribution was the topic most frequently used in practice by recent graduates. Perhaps most teachers would concur with Dr. Creed’s restricted coverage of moment distribution which emphasises physical principles and the stiffness nature of the technique. However, if this is the view of the teachers, what about the learners?
Concrete flat slabs are a popular form of flooring system used for a wide range of buildings such as offices, warehouses and carparks, since they provide large, uninterrupted floor areas with no downstand beams within a minimum construction depth. In flat slab construction without beams, two problems have to be avoided: (1) large deflections at service loads and (2) punching shear failures at column-slab connections. This note is concerned with the second of these problems. Deflections in flat slabs will be the subject of a subsequent technical note. P.S. Chana
One of the main problems in assessing the structural response of RC elements during fire is the non-linear temperature profiles through the depth of exposed elements, leading to a non-linear distribution of strains which violates the principle 'plane cross-sections remain plane'. To fulfil the planeity of cross-sections under fire conditions, self-generating self equilibrating stresses are developed, arising from the self-restraint of the cross-sections. As a consequence, and disregarding the side-effects of possible internal microcracking, an 'effective' temperature profile should be determined, resulting in a reduced effective imposed curvature and a reduced axial deformation of the element. T.P. Tassios and M.P. Chronopoulos