Analysis On The Structural Performance Of Traditional Chinese Furniture And The Design Improvement Of Mortise And Tenon Joint

Mortise and tenon joint is the main structure of the traditional furniture, which is theunification of technology and art. From the cultural perspective, the mortise and tenon structureis a typical feature of traditional Chinese furniture. From the mechanical perspective, thedestruction of most of the furniture is caused by insufficient strength of the joint, so it’s necessaryto design the joints according to the accurate strength. In the process of modernization oftraditional furniture, some enterprises pursuit to improve production efficiency with theinappropriate simplification of the structure of the traditional furniture, resulting in the loss of themost essential joining technology.The inheritance and innovation of traditional furniture lies in the mortise and tenon structure,which is not only the main structure of the traditional furniture having a certain artistic value, butalso an important indicator of whether traditional furniture could exist or not. Most studies ontraditional furniture ignore the importance of the structure, mostly paying more attention to thecultural factors such as appearance and shapes, or the application of pattern or lines, while notshowing the process of transformation of the image inherent in the spirit and technical qualities inthe structure of traditional furniture. This paper attempts to understand and apply the virtue ofmortise and tenon structure in traditional furniture from the broader view of point, transformingfrom the original studies of single linear models to the dynamic, diversified models oftransformation. Through organizing and classifying the origin, type, and cultural connotations ofdifferent kinds of mortise and tenon joints, also with the comprehensive applications oftheoretical mechanics and wood science theory, in-depth analysis of the structural characteristicsof the traditional furniture is carried out to verify the scientific and artistic nature of the mortiseand tenon joint structure, and explore possible ways of modernization of traditional furniturestructures, which will help integrate traditional furniture with modern life.In this paper, the main conclusions are as follows:(1) Proposing the concept of "key joints" from the perspective of the production andutilization of traditional furniture joint, classifying the joints into4types, namely joining thehorizontal and vertical member of top panel, joining the top panel with the main frame,assembling the main frame and joining decorative member to the main frame, this classificationwill build up the basis for the follow up improvement of traditional furniture structures.(2) Attempting to construct the mortise and tenon based modeling approach, the traditionalfurniture tenon joint structure as a symbol of the cultural context or system, and given a passsignificance as the carrier in order to arouse people’s cultural resonance.(3) Analyzing the integrity of the framed structure of traditional furniture while referring tothe mechanism of beam and beam reinforcement structures. The application of the beam in traditional furniture can be divided into three categories, namely variable cross-section beam,outrigger beam, and continuous beam. The reinforcement structure of the beam is mainly used inthe joining of legs, the waist apron and the top panel, which can be divided into three categories,namely horizontal stretcher, giant arched brace and brackets.(4) More representative mortise and tenon joints in traditional furniture are selected, namelythe mitered joint (two-dimensional), the mitered shoulder joints, the three-way mitered joints,andthe walking horse tenon, to carry out mechanical testing. The results of the test show that with theuse of the modern adhesives, the maximum of the strength of the mitered joints (two-dimensional)are as follows with the descending order, mitered bridle joint> rectangular mortise and tenon>traditional three-way mitered joint. Comparing with other forms of joining types, theperformance of the durability of the traditional three-way mitered joint is better than the otherjoints, with the curve of load-displacement not immediately descending when the destructionoccurs; The anti-pulling strength of the mitered shoulder tenon is higher than the rectangularmortise and tenon, it can be said that the design of the mitered shoulder tenon (virtual shoulder)is to solve the structural problems of traditional furniture, especially for anti-pulling out, ratherthan to enhance the bending moment strength; The bending strength and durability of traditionalthree-way mitered joint is good and it is worth paying attention that the bending moment capacityof traditional three-way mitered joint is different when we hold the short member or hold thelong member. It explains that the design of this structure is not only for avoiding cutting throughwhen two tenon meet together, but also considers about the strength; The running horse tenonlead to low pulling strength, which is not suitable for use in load-bearing parts. The anti-pullingstrength is decided by the shear strength of the wood. Usually the edge of the mortise and thetenon get sheared with the break line parrel to the grain.(5) With the application of the knocked down structure, Clamex P system has the greatpotentials, but the system is now only suitable for the members with the thickness greater than16mm, and width greater than85mm. According to the test of bending moment capacity, thestrength of the Clamex P system is decided by the mechanism that connect the plastic plate withmetal hook inside itself, while not influenced by the width of the member, so it’s necessary tostrengthen the mechanism that connect the plastic plate with the metal hook inside the Clamex Psystem, which will help this new joining system widely used in the joints of traditional furniture.(6) With the exploration of the improvement of three-way mitered joints,30specimens out of6groups which has different joining types are made to carry out the bending moment capacitytest. The test intimates the damage on the corner of the table, showing the strength of thedifferent joints as follows in descending order, double pin dowel> loose tenon> traditionalthree-way mitered tenon> dovetailed key> single pin dowel> magnetic screw. Invis magneticscrew gets low strength due to the magnetic screw system specially designed for the connectionsin MDF panel furniture, while not considering the connection of wood. The length of theembedded nut pieces, the height of the tooth, the distance between the pitch needs to be further improved if it is used in the joining of wood.(7) From the point of view of joint analysis, mortise and tenon joint in traditional furniture isdivided into two-dimensional and three-dimensional structures. By comparing the load anddisplacement curve of the bending moment capacity of two-dimensional structure withthree-dimensional structure, it is found that the three-dimensional tenon will not immediatelydecline after the breaking point, but showing a slow decline curve, which indicate that thethree-dimensional mortise and tenon structure has a better performance of bending durability,with the components interlocking and constraining with each other.