CREEP ANALYSIS METHOD OF CONCRETE STRUCTURES BASED ON COMPOSITE ELEMENTS

This paper evaluates the numerical calculation of concrete creep and proposes a calculation method for creep analysis of concrete structures. Based on the composite element, 3D model of concrete creep is created firstly. Then, according to the time-dependent variation of structural characteristics, recurrence formula is developed. Based on virtual work principle, concrete creep stiffness matrix is established, and equivalent load of free creep strain is obtained step by step. Generally, the composite element inherits and expands the features of original solid isoparametric elements, and considers contributions of steel and concrete to the element stiffness separately. Analyzing results show that the resistance effects of steel to the creep can be conveniently considered using the composite element, yielding more accurate prediction of the stress redistribution between concrete and steel and the calculation of displacements and internal forces of structures.