The Study On Joint Size Parameters Of Oval-tenon Of Pine

This thesis has studied systematically on joint size parameter of Oval-tenon joint of pine. The research divides into three parts: Impacting of tenon's shoulder over knot characteristic property; the impacting of distance between mortise and end of post over node characteristic property; Effect of Tenon width on characteristic property of joint. Obtain the following results:(1)For T-type joint, the ultimate bending moment capacity of joint increases along with the tenon shoulder size increasing. The relationship between the bending strength of the node and tenon shoulder is linear. When the tenon's width is 15mms, 20mms, 25mms, 30mms, the relationship between the bending strength of the node and tenon shoulder is given by these expressions: y=0.6786x+21.192,y=0.736x+27.722,y=0.8048x+29.531,y=0.3331x+45.443。The stiffness of joint increases along with the tenon shoulder size increasing.When the tenon size is large enough,the tenon shoulder is giving little contribution to the knot stiffness.(2)The increasing of end dishtance will enhance strength of L-type node. For L-type joint, relationship between the strength of the node and end dishtance is Quadratic. When the tenon's width is 15mms, 20mms, 25mms, 30mms, the relationship between the bending strength of the node and end dishtance is given by these expressions: y=-0.0133x~2+0.6042x+14.351,y=-0.0366x~2+1.3733x+22.576,y=-0.0218x~2+0.6192x+28.204,y=0.0056x~2+0.0991x+34.448。The relationship between the torsion strength of the node and end dishtance is given by these expressions: y=-0.009x~2+0.302x+8.2442,y=-0.0057x~2+0.1863x+11.029,y=-0.0569x~2+1.5739x+16.784,y=-0.0034x~2+0.5177x+23.923。The stiffness of joint increases along with the tenon shoulder size increasing.If the tenon size is large enough, the end distance is giving little contribution to the knot stiffness. When the mortise's end distance is less than 5mms from the end of the post, mortise is easy to crack in assembly process.(3)For T-type joint, the ultimate bending moment capacity of joint increases along with the tenon width increasing. relationship between the bending strength of the node and tenon width is Quadratic. When the size of tenon's shoulder is 0mms, 5mms, 10mms, 15mms, 20mms, the relationship between the bending strength of the node and tenon width is given by these expressions: y=0.0965x~2-2.6477x+38.857,y=0.1578x~2-5.4239x+72.475,y=0.0877x~2-2.3466x+44.826,y=0.1388x~2-4.3149x+67.864,y=0.2237x~2-7.484x+96.424。The stiffness of joint increases along with the tenon width increasing.Under the action of the shoulder, tenon sizes will play a greater role on joints characteristics property.