Research On The Design Of Folding Tables And Chairs Furniture Based On Flattened Bamboo Laminate

As a new type of bamboo laminated timber,flattened bamboo laminate can retain the physical properties and original texture of the bamboo timber,achieve the maximum utilization of materials,and have a larger development space in the design and manufacture of furniture.But its current application is still limited to kitchen utensils and decorative panels.Folding furniture has the characteristics of small storage space and easy portability,and the market prospects are considerable.Among them,folding tables and chairs are the most frequently used and most popular.However,it has higher strength requirements for the folding joints,so materials such as metal and hardwood are mostly used.This study based on the exploration of the physical properties and design attributes of the flattened bamboo laminate,according to the classification and folding principle of the folding structure,the flattened bamboo laminate table and chairs are designed through the structural design,and the finite element software is used to carry out the static analysis of the folding furniture.And component size optimization,and the feasibility of the design scheme is evaluated through model verification.The main research content and results of this article are as follows:(1)By testing the mechanical properties of flattened bamboo laminate made from single-layer bamboo flat plate,it was found that its compressive elastic modulus,shear modulus,and Poisson's ratio were close to those of the bamboo laminated timber.At the same time,the tensile strength(138.52 MPa),compressive strength(62.71 MPa),shear strength(16.44 MPa),front screw holding force(4297 N),bending strength(133.61 MPa)and other properties are better;the average values of dry and wet bonding strength reached 10.53 MPa and 9.07 MPa,respectively,meeting the performance requirements of folding furniture.Use this as an evaluation index of material performance to provide basic data for folding furniture design,finite element analysis and reduction treatment.(2)Based on the folding structure and material properties,taking the use environment as the design positioning,starting from the folding structure type and folding principle,the structure design of folding furniture is carried out,thereby designing flattened bamboo laminate tables and chairs with different degrees of folding.(3)The finite element software is used to carry out statics analysis on the folding chair made of flattened bamboo laminate.The results show that the maximum equivalent stress is 82.7 MPa when the seat surface is stressed alone,and the safety factor is 2.84>1,and the component size can be optimized.Based on this,after reducing the length and width dimensions of the frame member section by 5 mm in the subsequent design,the maximum deformation of the folding chair increased from 0.495 mm to 0.51 mm,the maximum equivalent stress reached 122.7 MPa,and the safety factor was 1.92;stress and The deformation is basically the same as before the size reduction.This shows that flattened bamboo laminate timber can meet the performance requirements of furniture,and can achieve component size optimization.(4)In order to consolidate the strength of the folded structure,the carbon steel connectors at the junctions were replaced with lightweight and high-strength aluminum alloys,and a combined static analysis of the seat surface and the seat back was carried out according to GB/T 10357.3-2013.The results show that the force and deformation of the folding chair at the two levels are the same,and the maximum deformation appears at the top of the backrest,which is 24.5 mm and 20.1 mm,respectively.The overall maximum equivalent stress appears at the position of the aluminum alloy connector,395.2 MPa and 323.15 MPa,respectively.The maximum equivalent stress borne by the flattened bamboo laminate appears on the back leg of the chair,which is 46 MPa and 40 MPa,respectively,which are both less than The ultimate strength of the two materials(485 MPa and 62.7 MPa),the safety factor is about 1.23 and 1.5.It shows that the structural strength of the folding chair can meet the requirements of use.(5)Based on the above research,a physical model was made,and static load,durability and impact tests were carried out.The results show that the change value of the seat surface deflection in the static load test is 0.49 mm,which is basically consistent with the finite element analysis results;the overall appearance of the folding chair before and after the force does not change significantly,and the use function is not affected at all,which verifies the feasibility of the design scheme.After the impact test and durability test,some connectors of the chair have reversibly loosened,but it does not affect the use,which proves that the folding chair made of flattened bamboo laminate can fully meet the requirements of use strength.