Study On The Seismic Performance Of New Assembly-type Concrete-filled Steel Tubular Frames

According to the uniform design standard, the assembly-type structure system, which consists of integrated modules and parts, achieves the anticipated function and meets the safety requirement in a manufacturing way involving factory prefabrication, in-place assembly and so on. In terms of the theory concerning with assembly-type structure and its practical application, this paper proposed a new assembly-type wall-board system.The new system has many advantages including normalization of standard design, industrialized production, integrated decoration, convenient transportation, construction assembly manner, energy efficiency and so on. The mechanical properties of plug-in beam-column joint,component,one common framework and overall structure in this new system had been stuied at present.It indicates that the joint can effective axial force, shearing force and bending moment,has good mechanical properties;the component and framework have high bearing capacity,stiffness and good hysteretic;the lateral ability, interlayer displacement and plastic hinge of the overall structure in accordance with the requirements of the specification.To ensure the mechanical property of the assembly-type concrete-filled steel tubular structure and provide useful sources of information for further research, this paper investigated the seismic performance of the ‘beam-column’ connection and the ‘double-deck, single-span’ frame by means of the finite element software(ABAQUS6.10). Results of the non-linear analysis can be seen as follows:(1) On the basis of given testing data, the structure was modeled using finite elements. For consistency, same condition and loading process were constructed for calculations and analyses. Compared with experimental researches, it can be noted that the calculation results involving the stress and strain nephogram, the failure mode, the hysteretic curve and the skeleton curve coincide well with the experimental situation. Therefore, such modeling approach and numerical calculation are so rational that they can model the seismic performance of the ‘beam-column’ connection and of the ‘double-deck, single-span’ frame in an accurate way.(2) Whilst applying monotonic and low-cycle loads, the hysteretic curve of assembly-type concrete-filled steel tubular column is plumper, which implies good properties of the column involving bearing capacity, rigidity, ductility and energy consumption. The failure mode in these results also meets the required characteristics of ‘strong column, weak beam’ and ‘strong connection, weak connected member’ mechanism. The effects on seismic performance associated with the steel ratio, the brace thickness, the width-thickness ratio of muff, the axial compression ratio and the property of filled concrete were taken into account in the meantime. As shown in calculation, the increase in the steel ratio or in the brace thickness leads to the improvement of bearing capacity and rigidity. For the width-thickness ratio of muff and the axial compression ratio, however, they are almost irrelevant. In addition, the seismic performance of structure can be improved greatly whilst filling concrete into the square steel tube.(3) Performing similar numerical modeling for the ‘double-deck, single-span’ frame, we can conclude that:(a) the stress and strain nephogram and the failure mode are acceptable,(b) the hysteretic curve presents a spindle-shaped profile which implies a good seismic performance,(c) the increase in these parameters involving the steel ratio, the brace thickness and laminate thickness of truss is beneficial for the improvement of bearing capacity and rigidity,(d) the axial compression ratio should be adjusted to a state of high energy efficiency and(e) the filled concrete play an important role in the improvement of above indicators related to the structural quality.