Effects of tightening speed on torque coefficient in lag screw timber joints with steel side plates

Author

• Doppo Matsubara
  • 1
  Email author
• Yoshiaki Wakashima
  • 2
• Yasushi Fujisawa
  • 2
• Hidemaru Shimizu
  • 3
• Akihisa Kitamori
  • 4
• Koichiro Ishikawa
  • 5

1. 1.Tokyo Metropolitan Industrial Technology Research InstituteTokyoJapan
2. 2.Toyama Prefectural Agricultural, Forestry and Fisheries Research CenterImizuJapan
3. 3.Sugiyama Jogakuen UniversityNagoyaJapan
4. 4.Research Institute for Sustainable HumanosphereKyoto UniversityUjiJapan
5. 5.University of FukuiFukuiJapan

Original Article

First Online: 12 December 2017

Abstract

To investigate the effects of tightening speed on the torque coefficient in lag screw timber joints with steel side plates, tightening tests were conducted on main timber members made from Cryptomeria japonica, Chamaecyparis obtusa and Pseudotsuga menziesii, under four tightening speed conditions (1, 4, 10, and 20 rpm). Major stick-slip behavior was observed in C. obtusa based on the relationship of tightening angle with clamp force, tightening torque, and thread torque at tightening speeds of 1 and 4 rpm. In addition, tightening speed’s effects on the torque coefficient (K) varied depending on the wood species of the main member. In P. menziesii, K was not affected by the tightening speed: the ratio of torque expended on tightening was 25% on average, and the ratio of torque expended on bearing surface friction was higher than the ratio of torque expended on thread friction.

Acknowledgements

This work was supported in part by the Science and Technology Research Promotion Program for Agriculture, Forestry, Fisheries and Food Industry.

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Copyright information
© The Japan Wood Research Society 2017

For further details log on website :
https://link.springer.com/article/10.1007/s10086-017-1679-3