Experimental Study And Analysis On The In-plane Deformation And Stiffness Performance Of A New Kind Of Assembly Composite Floor

It is of great significance for the overall structure analysis to verify the in-plan stiffness performance of floor structure system.Based on the assumption of rigid diaphragm of floor,the structural calculation process and analysis of calculation results are greatly simplified for the number reduction of analytical freedom;While,for the semi-rigid or flexible floor system,the overall structure analysis become a little more complex,because during the structural analysis,the deformation of the floor diaphragm must be taken into consideration.How to evaluate the in-plan stiffness performance of floor structure system,there are no specific regulations in Chinese design code at present.For a new kind of assembly composite floor system suitable for multi-columns bundle tubes tall steel structures system,experiments research and finite element analysis were carried out in this doctoral dissertation.The in-plan stiffness performance and correlation influential factors are analyzed and discussed in detail,which can provide an important basis for the engineering applications of such a floor structure system.(1)Firstly,based on the reveals in detail for the configuration and assembly method for the new kind of assembly composite floor system,experimental research and theoretical analysis were made to investigate the bearing capacity and initial stiffness of the key assembly joints for the floor system.For the shear-resistant connection and tensile-resistant connection of such kinds of assembly joints,like high-strength bolted joints with internal sleeve,high-strength bolted joints with filler plates,the full scale tests and correlative finite analysis are conducted.The research results show that,the connection behavior is good for the shear-resistant and tensile-resistant of the high-strength bolted joints with internal sleeve;the application of filler plates caused a certain adverse effect on the shear-resistant of high-strength connections,but such a influence is not significant,the decreased shear capacity is less than 8%.(2)Two sets with four 1/3 reduced-scale floor models are designed and produced,the first set is to consider the behavior of floor system which the direction of horizontal force in the floor plan is parallel to the assembly seams of floor system,and the other set is to consider the behavior of floor system which the direction of horizontal force is perpendicular to assembly seams of floor system.Each sets of model includes two reduced-scale floor samples with the same configuration,one is two storey frame with the test object located on the second floor,the other is a single storey frame with the test object located on the first floor.The research results show that:the integrity in the direction of perpendicular to slab seams of assembly composite floor system is worse than that in the direction of parallel to the slab seams,while,the in-plane stiffness performance in the direction of perpendicular to slab seams is better than that in the direction of parallel to the slab seams;for the floor system with the same configuration,the in-plane stiffness behavior is better located in the second floor than that in the first floor.According to the evaluation method specified in ASCE7-10,the second floor system and the first floor system all belong to semi-rigid floor when the horizontal force in floor plan is parallel to the slab seams of assembly composite floor system,if the horizontal force is perpendicular to the slab seams,the second floor system is rigid but the first floor system is semi-rigid.(3)Based on the experimental study and analysis on the behavior of the key assembly joints of floor system,the simplified mechanical analysis models can be get for these joints.Then we can make the simulation and analysis for the in-plan stiffness behavior of assembly composite floor system using the Midas finite analysis soft,and conduct the comparison between the analysis results and test results.The study shows that;the results based on the Midas analysis are consistent with the experiment data,the analytical model based on Midas is suitable and valid for the simulation analysis on the new kind of assembly composite floor system.(4)Analysis research are conducted on the in-plan stiffness behavior of practical engineering floor systems by using the simulation method with Midas soft.Combined with the comparative analysis of the two capabilities of in-plan deformation and transmit and transfer for horizontal force between the three kinds of floor system:assembly composite floor,assembly integrated composite floor and floor system rigid floor,the in-plan stiffness behavior of the new kind of assembly composite floor system has been analyzed and evaluated using the evaluation method specified in ASCE7-10.(5)In the case that all the assembly joints meet the design requirement,for the new kind of assembly composite floor system with the thickness of face plate 73mm,the floor system located on the second floor belongs to rigid floor,and the system located on the first floor belongs to semi-rigid floor when they are sustained horizontal force in the direction parallel to the slab seams,while,they will belongs to rigid floor whether in the direction parallel to the slab seams or perpendicular to the slab seams if they are sustained horizontal force in the direction perpendicular to the slab seams.1.The integrity behavior of the assembly composite floor system is better in the direction of parallel to slab seams than that in the direction of perpendicular to the slab seams.2.The in-plan stiffness behavior of the new kind of assembly composite floor system is better in the direction of perpendicular to the slab seams than that in the direction of parallel to the slab seams.3.The in-plan stiffness behavior of the new kind of assembly composite floor system is related to the floor location:as to the two floor system with the same configuration(the effective thickness of concrete face plate is 73mm),the one located on the second floor is rigid floor while the other located on the first floor belongs to semi-rigid floor system.4.The stiffness of key assembly joints affects the in-plan deformation and stiffness behavior of the assembly composite floor system greatly.Among all the assembly joints,the influence of these two kinds of joints is most marked:joints between slab to slab and joints between slab-corn column.