SIMPLIFIED CREEP ANALYSIS OF COMPOSITE BEAMS WITH FLEXIBLE CONNECTORS

The paper presents some approximate solutions for the time-dependent a nalysis of composite steel-concrete beams with flexible shear connecto rs. These permit evaluating the migration of the stresses from the con crete slab to the steel beam and the increment of the deflections, whi ch occur gradually with time as a result of creep and shrinkage of the concrete part. The mathematical formulation of this problem, which in volves a coupled system of three equations, with two being integral-di fferential-type equations, is reduced to a system of ordinary differen tial equations by applying the algebraic methods (age-adjusted-effecti ve-modulus, effective-modulus, and mean-stress methods). The simplific ations introduced by these methods permit obtaining solutions in close d form, which can be useful for practical applications. The accuracy o f the numerical results is successively estimated by comparing these v alues with those of the exact numerical solution, obtained by employin g the numerical algorithm proposed elsewhere using the numerical step- by-step procedures of the general method.