A novel method and validation for obtaining the optimal interference fit of round-end mortise-and-tenon joint

ABSTRACT

To determine the optimal interference fit of mortise-and-tenon (M&T) a novel method is proposed. To validate its effectiveness, compression tests were conducted considering the effects of wood species (beech and western hemlock), tenon widths (30, 40, 50 mm), and grain orientations (radial, diagonal, and tangential) to obtain the optimal interference fit and contact force (CF). Furthermore, the mounting force (MF) and withdrawal force capacity (WFC) of T-shaped M&T joints constructed by the control and optimal interference fit were evaluated by compression and withdrawal tests, respectively. The results indicated that (1) all three evaluated factors had significant effects on the tenon compression behavior and CF; (2) the derived optimal fits showed that the tenon with a larger width required a higher fit value based on regression equations; (3) the MF and WFC were significantly affected by the three evaluated factors and proportional to the tenon fit; (4) the maximum WFC occurred at the M&T joints made of western hemlock with 50-mm tenon width in tangential orientation with 0.99-mm interference fit, and the beech with 30-mm tenon width in diagonal orientation with 0.78-mm interference fit. The proposed method will assist the wood product manufacturers to design M&T joints rationally.

KEYWORDS:

• Wood furniture joint
• mortise-and-tenon
• tenon fit
• withdrawal force capacity
• mounting force

Acknowledgments

The authors would like to express their heartfelt thanks to Canada Wood China Representative Office for providing the experiment materials and Yan Liu and Zhonghui Tian from the Department of furniture design of Nanjing Forestry University for their help during the experimental test. Meanwhile, the authors thank the anonymous reviewers and editors for their valuable comments and suggestions for improving the quality of this paper.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was partially supported by the Postgraduate Research & Practice Innovation Program of Jiangsu Province [grant number KYCX21_0905] and partially supported by a project funded by the National First-class Disciplines (PNFD).