A multi-scale structural model for coupling 1d with 3D elements

In most framed structures the nonlinearities and the damage are localized, extending over a limited length of the structural member. Therefore the segments of a member that have entered the nonlinear range may need to be analyzed by three-dimensional (3Delements whereas the rest of the member can be modeled by simpler one-dimensional (1Dbeam elements with fewer degrees of freedom. The proposed Multi-scale model couples the small scale solid 3D elements with the large scale 1D beam elements. The mixed dimensional element coupling based on the kinematic coupling technique of ABAQUS software is implemented for the analysis of the solid and the beam elements. The analysis results are compared with test results of a reinforced concrete pipe column and a structure consisting of reinforced concrete columns and a steel space truss subjected to static and dynamic loading. The same structures are analyzed using 3D solid elements for the entire structure. A comparison of the accuracy and the computational effort indicates that by the proposed Multi-scale method the accuracy is almost the same but the computational effort is significantly reduced.