Results of elasto-plastic finite element analysis are presented for panels having boundary conditions appropriate to full-depth web panels, for square, long and tall panels with side ratios ranging from 1 to 5 and with b/t ratios 80, 120, 180. Convergence studies are described, and it is noted that shear panels require a finer mesh than compression panels. Stress-strain curves are given for all solutions: whereas the ductility varies, maximum resistance occurs at a strain approximating to the shear yield strain. Principal stresses are compared with alternative tension field models, which differ more from each other than they do from the computed tension fields. Unlike the models, extensive yielded zones do not develop until after maximum resistance has been reached. J.C. Chapman and P.C. Davidson
Current practice assumes that restrained shrinkage causes tension in concrete, even when the concrete is cracked. This paradox leads to irrationality in the design of non-compact continuous composite beams. The results are given of long-term studies of the interactive effects of shrinkage, creep, and external loading, on the cracking and elastic stiffness of hogging moment regions of two 12m composite beams. A matching conceptual model is found, for use in design calculations. Primary shrinkage curvature is halved by cracking of the concrete. Allowance for this would lead to some economy in composite members with long regions in hogging bending and to more accurate predictions of deformations. Professor R.P. Johnson