EXPERIMENTAL RESEARCH ON MECHANICAL PROPERTIES OF DOUBLE-LAYER SHOULDER BEAMS WITH TRIPLE-LIMB SIDE COLUMNS OF CONCRETE-FILLED STEEL TUBES

In order to study the mechanical property and failure mode of double-layer shoulder beams, so as to provide theoretical support for the design of the double-layer shoulder beam, three specimens of double-layer shoulder beams with triple-limb side columns were designed and tested under monotonic loading. By changing the action position of the inner limb of the middle column on the lower shoulder beam, the effects on the yield load, strain of the main parts, yield mechanism and failure mode of specimens were analyzed. The results showed that the yield of the inner limb web of the lower shoulder beam was the control factor of the yield load for specimens, which could reflect the yield of specimens very well. The yield load of specimens could be determined by the yield of web plates; the bearing capacity of the double shoulder beam was improved in the process of outer shift for inner limbs of middle columns; the failure of specimens was due to the shear type convex deformation of side webs for inner limbs of lower shoulder beams.