Study On Mechanical Properties Of Corner Joint Of Glued Laminated Bamboo Furniture

The corner structure of furniture is a very important part of the whole furniture structure.The strength of corner joint will affect the stability of the whole furniture.The corner bonding strength of glued laminated bamboo furniture connected by hardware connectors is different from that of other timber.This study takes the corner joint of glued laminated bamboo furniture as the research object,and compares and analyses the strength performance of different hardware connectors m the corner joint.On this basis,the corner joint of self-tapping screw with better connection performance was selected,and its fatigue resistance was further studied.Combining Burger model and Kelvin model,a mechanical model describing its deformation and recovery was established,which could provide some reference for improving the corner joint performance of glued laminated bamboo furniture and structural design of glued laminated bamboo furniture.The main conclusions of the study are as follows:(1)Corner structure is ubiquitous in different types of glued laminated bamboo furniture,such as chairs and tables,mainly in the L-shaped coner structure,cabinet glued laminated bamboo furniture mainly in the "T" corner structure.The main reasons for the destruction of corner structures connected by hardware connectors are:the destruction of glued laminated bamboo,the destruction of hardware connectors,the destruction of both glued laminated bamboo and hardware connectors.(2)In the test of bonding strength of cormer structure of glued lammated bamboo furniture,mean values of the maximum static load mean values of self-tapping screw connection,t,wo-in-one connection and three-in-one connection are 330.06N,348.30N and 115.26N respectively in the close direction,and 272.13N,305.78N and 106.61N in the open direction.Through comprehensive companson and analysis of these three kinds of hardware connectors,self-tapping screw was selected for subsequent fatigue resistance test.(3)In the fatigue resistance test of comer structure of glued laminated bamboo furniture,the fatigue resistance was tested and analyzed according to the four gradients of 80%,70%,60%and 50%of the maximum static load.The change of the angular displacement of the sample structure was obtained under the impact of 5000 times of force,and the linear regression analysis was earried out with the angular displacement data obtained.The results show that the impact force(F)and impact force(50%).The number of hits(n)and the direction of impact(D)have significant effects on the angular displacement(degree)at a significant level of 1%.(4)Combining Burger model and Kelvin model,the mechanical model of corner structure connected by self-tapping screw is deduced,and the corresponding equations describing the deformation and recovery are obtained.The difference between the delayed elastic constants kde and the damping constants rde is not more than 14.52%and 9.02%respectively,and the delayed elastic constants and the damping constants for deformation recovery are larger than the delayed elastic constants and the damping constants for deformation recovery.In the deformation process,the cumulative loss of the specimen structure leads to the decrease of its delayed recovery ability,which leads to the higher values of the delayed elastic constants and damping constants derived from the deformation recovery curve.