Application of commercial FEM program Abaqus to investigate delamination behavior of post-tensioned concrete curved walls

The concrete delamination induced by prestressing forces is a potential problem of post-tensioned concrete containments with curved geometry. To investigate the concrete delamination mechanism, the researchers of the University of Texas at Austin completed an experimental research project in 2017. In this research project, the academic finite element method (FEM) program VecTor4, which has powerful shell-type elements for cracked reinforced concrete shells, was modified and proved to be an appropriate tool to predict the level of applied prestressing load at the delamination failure. VecTor4 has a well-defined reinforced concrete material model and capability to analyze the structures on an overall system level with low computational resources. However, its user interface has limitations, and the details of the local behavior of structures may not be captured due to its simplicity. On the other hand, commercial FEM programs generally provide a convenient graphical-based user interface and various analysis features. Still, typical commercial FEM programs are not designed to analyze the concrete structures. Some commercial FEM programs provide concrete material models; however, they tend to require significant calibration analyses to capture the behavior of reinforced concrete structures. Specifically, to capture the delamination of concrete walls with those programs, solid elements should be selected, which should increase the computational costs. However, commercial FEM programs can potentially provide the details of the local behavior of structures. Recently, an experimental test investigating the concrete delamination phenomenon was conducted. In this recent test, numerical analyses with the commercial FEM program Abaqus ware conducted as well as the analysis with VecTor4 to explore other options in commercial FEM programs. This paper will show the analysis results of both Abaqus and VecTor4 for the recent test. Additionally, the discussion on the relative merits and limitations of these programs obtained from the experience of the analyses for the recent test is presented.