ABSTRACT
The paper describes a combined numerical and experimental study of the high strength CHS steel stub columns which material is Grade 590 centrifugal cast steel. The purpose of the research was to obtain some fundamental information about elastic-plastic behaviour of the high strength CHS steel columns with small diameter-to-thickness ratio.
The experimental work consisted of 15 stub column tests (D = 200 mm, L = 3D) with parameters of diameter to thickness ratio (D/t = 13,17, 25, and 33) and the yield ratio of material (Y = 0.73-0.81 and 0.87) was carried out. The numerical work was carried out by ABAQUS version 5.3 using with the axisymmetric elements. It was involved 15 numerical analyses of Finite Element models simulating the specimens tested and 25 numerical analyses of Finite Element models with parameters of diameter to thickness ratio (D/t = 10, 20, 30,40, and 50) and the yield ratio of material (Y = 0.5, 0.6, 0.7,0.8, and 0.9) for investigating the effect of the parameters on the strength and the deformation capacity of the column members.
Evaluations of the test and the analysis results showed as follows: (1) the high strength CHS steel columns with D/t < 20 had some excellent characteristics compared with others (D/t > 20), (2) the effect of the difference between the mild and the high-strength steel on the strength and the deformation capacity of CHS column is evaluated as the yield ratio of material, F, being their parameter, and 3) finally, the experimental formulae for predicting the maximum stress index and the deformation capacity of CHS columns were proposed from the regression analysis considering the test and numerical results.
