Cconcrete-encased CFST box stub columns under axial compression

In this lesson, the analysis of the concrete-encased CFST box stub columns under axial compression is investigated. The concrete column is modeled as a three-dimensional solid part. The steel pipes are modeled as a three-dimensional solid part, and the steel bar and strips are modeled as the wire part. The concrete parts that filled the steel tube are modeled as three-dimensional solid parts. The concrete-encased concrete-filled steel tubular (CFST) box column, which consists of the reinforced concrete (RC) box column with several CFST components embedded in web walls and corners, has been developed and increasingly used in bridge arches and piers in China. There are six CFST components in this hollow composite column: four in the corners and two in the RC web walls. The diameter of the CFST components in the corners is usually set to be larger than that of the CFST components in the web walls to increase their flexural capacity. Compared with the conventional RC columns or the concrete-encased CFST columns, this composite column has a higher bearing capacity and construction efficiency. The concrete Damaged Plasticity material model is selected. The CDP material model represents a constitutive model that is based on a combination of the theory of plasticity and the theory of damage mechanics. This material model is often used in solving geotechnical problems due to its realistic description of the mechanical behavior of concrete material. The steel material with elastic-plastic behaviour is used for all steel parts. The dynamic explicit step with the mass scale technique is considered. The general contact algorithm for all parts is selected. All constraints are assigned to the part.