Seismic Behavior And Design Methods For Semi-rigid Composit Joints To Concrete-filled Steel Tubular Columns

Steel tube concrete with high bearing capacity, plasticity and toughness, goodproduction and construction is convenient, refractory performance is good, theeconomy is good wait for a characteristic. In present the H steel composite columnthe endplate connected node to research more, but for steel tube concrete columnand the composite board connected node research is rare. By using the method ofcomponents of semi-rigid combination of concrete filled steel tubular frame nodeflexural strength, initial stiffness and rotation ability of the calculation model andthe calculation method, with the actual engineering as a reference and design basis,and carry out the research:(1) In this paper four-full scale semi-rigid steel tube concrete combination frame of thenode low cyclic loading test. Study the column section type parameters are and the boardtype, detailed survey of the combination of the node horizontal load-horizontaldisplacement hysteresis curve relationship with skeleton curves, moment-rotationrelationship hysteresis curve and skeleton curves, failure pattern, stiffness and strengthdegradation, ductility coefficient, energy dissipation capacity and key parts of straindistribution, etc. Experiment shows that the combination of concrete filled steel tubularframe board connected node with high strength, stiffness and ductility, can be safe andreliable used in multilayer bending combination frame structure.(2) Consider the bearing capacity of the concrete floor and destroy the form of influence,establish mechanics calculation model, the flexural strength into combination in the floorconcrete, steel and each of the high strength bolts are under tension or pressure.Determining concrete, steel, high strength bolt stress components such as the ultimatebearing capacity, according to the mechanical balance condition node and calculated atdifferent location in the shaft, the combination of the corresponding node tension capacity.(3) The calculation of European standard reference proposed initial stiffness componentswhilst node method, analyzes and discusses the contribution of connection stiffness have aseries of components: combination of floor concrete, steel, shear the stud, the high strengthbolts and bolt at the end of the welding of steel anchor role. Will these components fordifferent simplified stiffness, the force will deform ‘spring’, the ‘spring’ parallel or tandemcombination rises, a simplified model. Each component of the initial stiffness andsimplified model compatibility equations of deformation, get combination node of the initial rotary stiffness.(4) Discussed combination node in the negative moment is bending moment, under theaction of performance. For negative bending moment tension capacity corresponding to thelimit of the combination of the reinforced concrete floor reached its limit within strain; Forthe moment is the limit role tension capacity corresponding to the concrete composite floorpressure of destruction. In that column wall not occur under the condition of the localbuckling, the combination of the node rotation ability judgement this kind of semi-rigidconnection ductility whether meet the requirements.(5) In the comprehensive front of research contents of each chapter are put forward, basedon the combination of semi-rigid concrete filled steel tube bending moment-corner nodesframework design of some opinions relationship, through the test the reliability of thesimplified calculation method, and puts forward some Suggestions on the actual design.