Research On Size Effect Of GFRP-concrete-steel Double Skin Tubular Columns Under Axial Compression

In order to study size effect on the mechanical properties of GFRP-concrete-steel double skin tubular columns,on the basis of geometrical similarity,this paper analyzed factors of curves of load-displacement, load strain curves and stress-strain relationship under the several conditions of different sizes and strength grade of concrete by experimental study of 9 specimens.On the basis of experimental result,this paper established the numerical simulation model and analyzed the load strain curve, ultimate stress changes and stress-strain curves of specimens of 20 under 3 conditions of different size,strength grade of concrete and GFRP tube wall thickness.Combined with the experimental results, corresponding conclusion be obtained.The main contents and results are as follows:1, By controlling length to diameter ratio, GFRP tube wall thickness, concrete strength grade,according to the results of the experiment, this paper had analyzed change laws of limit stress,curve of load- strain, curve of load-displacement, curve of stress-strain, failure mode under different size of specimens.2, By controlling length to diameter ratio, GFRP tube wall thickness, improve the grade of concrete strength, according to the experimental results, this paper had analyzed change laws of limit stress, curve of load- strain, curve of load-displacement, curve of stress-strain, failure mode under different size of specimens.3, By controlling length to diameter ratio,concrete strength grade, changing the wall thickness of GFRP tube,according to the results of experiments, this paper had analyzed change laws of limit stress, curve of load- strain,curve of load-displacement,curve of stress-strain, failure mode under different size of specimens.4, Finally, on the basis of data obtained from above,this paper summarized the influence of size effect on mechanical properties of GFRP-concrete-steel double skin tubular column by analyzed the influence factors of limit bearing force,curve of load- strain, curve of load-displacement,curve of stress-strain, failure form under the conditions of different size,strength grade of concrete and GFRP tube wall thickness to reveal the influence of size effect on the mechanical properties of GFRP-concrete-steel double skin tubular column under compression.