Development of CSMM-Based Shell Element for Reinforced Concrete Structures

Reinforced concrete (RC) shell structures have been widely used in a variety of modern engineering applications. It is found from the earthquake reconnaissance that the RC shell structures, such as nuclear containments, cooling towers, roof domes, shear walls, are the key elements to resist earthquake disturbances. This research presents the development of a finite element analysis (FEA) program to predict the inelastic behavior of RC shell structures. In the program, a new shell element, so-called CSMM-based shell element, was developed based on the formulation of the degenerated shell theory with layered approach and taking into account the Cyclic Softened Membrane Model developed at the University of Houston. An analysis procedure was developed to perform nonlinear analyses of RC shell structures using the developed CSMM-based shell element. To develop the FEA program, the developed shell element and the proposed analysis procedure were implemented into a finite element program development framework, OpenSees, which was developed at University of California, Berkeley. Several large-scale structural tests were used to validate the developed FEA program, including panels subjected to pure shear or combination of shear and bending, a three-dimensional (3D) RC shear wall, a cylindrical RC tank, and circular and rectangular RC hollow bridge columns. More importantly, the versatile application of the developed finite element analysis program SCS-3D was further investigated by the modeling of two 1/13-scaled nuclear containment vessel specimens and a two-story unsymmetrical RC building subjected to reserved cyclic loadings. Both test programs were undertaken as part of an international collaboration projects between the National Center for Research on Earthquake Engineering (NCREE) in Taipei, Taiwan, and the University of Houston (UH), Houston, Texas. The experimental work was performed at NCREE, and the specimen design and study of the experimental results were performed at UH.