Research On Bending Behavior Of Bolted Glulam Beam-to-column Connections

Modern wood structures are often used in large-span,multi-story or high-rise buildings,so the joints need to be sufficiently rigid under external loads to withstand large shear forces and bending moments to meet design and application requirements.The wood bolt-steel filler node replaces the traditional connection method and is widely used in the modern glulam structure connection method because the node has high bearing capacity and good ductility.Glued wood bolts-Steel slab joints can withstand bending moments and can be rotated,with the common characteristics of hinged and rigid joints,exhibiting semi-rigid properties.The stiffness of the joint decreases with the increase of the load and changes nonlinearly.It has been shown that the joints are prone to brittle failure of wood transverse grain splitting under the action of bending moment,which in turn affects the seismic performance and safety of the overall structure.At present,there are few studies on the mechanical behavior of glulam beam-column joints in China,and it is of practical significance to strengthen this research.In this paper,the refined finite element analysis of the glulam beam-column joints is carried out.According to the classical finite element theory and the analysis of solid modeling,the experimental results are compared with the existing experimental results.The verification shows that the finite element model deformation and stress The distribution and test results are in good agreement,and the size of BCJ1(20mm diameter,70 mm bolt margin)is more reasonable from the calculation results.This node size design makes the joints have better ductility;When the number is increased from 2rows to 3 rows,the strength of the node is increased by more than 25%,and the stiffnessis increased by more than 10%.When the friction coefficient increases from 0.2 to 0.5,the joint stiffness and ultimate load increase gradually;when the elastic modulus of the grain and the transverse grain is increased,the joint stiffness and the ultimate load do not increase substantially.On this basis,the joint form of the glulam bolt-steel filler joint is briefly introduced.When the joint is subjected to the axial force,the lateral force and the bending moment,the force state is theoretically analyzed,and the glulam bolt is proposed.-The method of establishing the skeleton curve of the steel filling plate and the appropriate theoretical calculation model to calculate the nominal yield point load and displacement of the joint,the peak point load and displacement,and the calculation method of the joint stiffness,and the theoretical calculation of the skeleton curve and experimental fitting The skeleton curves were compared and matched well.