ALGEBRAIC METHODS FOR CREEP ANALYSIS OF CONTINUOUS COMPOSITE BEAMS

This paper proposes a simplified time-dependent analysis for continuou s steel-concrete composite beams with flexible shear connection, subje cted to static actions, settlements of the supports, shrinkage, and pr estressing of the concrete slab. By approximating the integral terms w ith particular quadrature rules (algebraic methods), the integral-diff erential system, which governs the problem, reduces to a differential system. This provides approximate solutions of the viscoelastic proble m directly at the final time, without having to consider the real stre ss history. Some of the algebraic methods known in the literature (e.g ., effective modulus, mean stress, and age adjusted effective modulus methods) are applied to continuous composite beams subjected to the fo ur different actions examined separately. Subsequently, the numerical results obtained are compared with the results of the accurate numeric al analysis (general method), and the validity of each simplified meth od is discussed. Finally, some information on the practical applicatio n of the effective modulus and the mean stress methods by means of rou tine computer programs, are given.