Based on equilibrium and compatibility conditions, as well as a stress
-strain relationship for softened concrete, a truss model theory for r
einforced/prestressed concrete box tubes subjected to static torsions
was applied to determine the torque-twist relationship as the primary
curve for the purpose of dynamic analysis. In this Paper, the inelasti
c response of reinforced/prestressed concrete box tubes to dynamically
applied torsions is predicted using the primary curve obtained by the
truss model theory, the hysteresis loops model proposed for shearwall
s and the linear acceleration step-by-step method. Furthermore, the al
gorithm is described, and a numerical example is given.