The Study On Joint Property Of Oval-tenon Of Pine

This article has studied systematically on the mechanics characteristic of Oval-tenon joint of pine . From four parts that the tolerance parameter about the thickness of tenon and the width of mortise , the tolerance parameter about the width of tenon and the length of mortise based on the transverse compress estimate of wood , the length change of tenon and the tolerance parameter about the width of tenon and the length of mortise by fission-tenon to study on the influencing elements about the ultimate pullout of Oval-tenon , and obtain the following results :(1) Both T-type joint or L-type joint, When the Tolerance parameter (a) is 0-0.2mm, the ultimate pullout capacity of the junction point of in the Oval-tenon joint is the best, and the numerical value is 3823.54N, The Expression of the connection about the ultimate pullout capacity (P) and the Tolerance parameters(a) is: P= -9842a2+2746.1a+3460.4.(2) Both the radial grain and the chordwise grain have a rule that, by the growth of the width of tenon, the ultimate parameter also become higher, the trend line of the radial grain is small than the chordwise grain's. It is because that the the radial grain compress is to press springwood and the chordwise grain is to press summer wood.(3) As the length of tenon became longer, the ultimate pullout of Oval-tenon also became higher as a bias line. When the length of tenon reached about 30mm, the ultimate pullout did'nt become higher any more. The Expression of the connection about the ultimate pullout capacity (P) and the length of tenon(L) is: P=-4.6936L~2+ 377.41L-2000.3.(4) When the Tolerance parameter (c) is in the range of 0.4-0.6mm, the ultimate pullout capacity of the junction point of in the fission-tenon joint is the best, and the numerical value is 5700N, The Expression of the connection about the ultimate pullout pullout capacity (P) and the Tolerance parameters(c) is: P=-1628.5c~2 +1633.2c+4794.4.