Research On Behavior Of Core Steel-tube Reinforced Concrete Column Post Fire During Constant Loading In Axial Compression

Core steel-tube reinforced concrete column can be reasonably utilized the advantagesof steel and concrete material, which has high bearing capacity, simple construction,convenient nodes, good anti-seismic performance, fire resistance and good performanceadvantages, in recent years has been widely used in large span, high buildings. But themodern society with the development of economy, the improvement of people's livingstandard, the frequency of fires increased year by year, causing economic losses andcasualties increasing. Therefore, the core of concrete filled steel tube column, in itsanalysis of the fire under the force performance is very important.In this paper, using finite element analysis software ABAQUS reasonable selection ofthermal parameters, accurate boundary conditions as well as the actual fire temperaturecurve, solve the core of concrete filled steel tube columns in fire condition the sectiontemperature distribution, and the test results are verified; home, on the steel and concretethermodynamic performance parameters, selection of suitable constitutive relation, failurecriterion and the solving method, the concrete filled steel tubular column in force-heatunder the action of mechanical properties were studied, focusing on loading at normaltemperature, temperature rise during constant loading, loading to disrupt this processunder fire, steel and steel pipe concrete, mechanical properties and room temperatureloading to destruction of the difference; effect on concrete filled steel tubular column loadholding temperature limit bearing capacity parameters were analyzed, the initial axialcompression ratio, reaction time, fire tube restraint coefficient, coefficient of position isthe effect of core column load holding temperature limit carrying capacity of the mainfactors, and the longitudinal reinforcement ratio and stirrup rate on the core column loadholding temperature limit bearing capacity has little effect on the conclusion.