Relationship between clamp force and pull-out strength in lag screw timber joints
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This study empirically examines the relationship between clamp force and pull-out strength in lag screw joints of timber members, using data obtained in tightening tests and pull-out tests. Maximum clamp force per unit screw length as determined from the tightening tests was lower than the lower bound for the 95% tolerance range for pull-out strength per unit screw length as determined from the pull-out tests. Moreover, X-ray CT (computed tomography) observations of anchor members from both tests revealed that failure behavior clearly differed between the tightening test and the pull-out test: tightening caused damage to the wooden, female thread in addition to major splitting damage in the wood perpendicular to the grain near the tip of the lag screw.
KeywordsLag screw joints Clamp force Pull-out strength Tightening test
This work was supported in part by the Science and Technology Research Promotion Program for Agriculture, Forestry, Fisheries and Food Industry.
- 1.Japan Timber Engineering Society (2012) ISBN:978-4-7530-1856-7 C3052. Inoue-shoin Co. Ltd., Tokyo, pp 173-175Google Scholar
- 2.Tokuda M, Hirashima Y, Matsubara H (1989) The strength of lag-screw joints I. Lateral strength parallel to the grain (in Japanese). Mokuzai Gakkaishi 35(6):473–481Google Scholar
- 3.Tokuda M, Hirashima Y, Matsubara H (1989) The strength of lag-screw joints II. Lateral strength perpendicular to the grain (in Japanese). Mokuzai Gakkaishi 35(6):482–488Google Scholar
- 4.McLain TE (1997) Design axial withdrawal strength from wood I. Wood screws and lag screws. Forest Prod J 47(5):77–84Google Scholar
- 5.Pirnbacher G, Brandner R, Schickhofer G (2009) Base parameters of self-tapping screws. In: Proceedings, CIB-W18, Dubendorf, paper 42-7-1Google Scholar
- 6.Frese M, Blass HJ (2009) Models for the calculation of the withdrawal capacity of self-tapping screws. In: Proceedings, CIB-W18, Dubendorf, paper 42-7-3Google Scholar
- 8.Kobayashi K, Yasumura M (2013) Influences of number and spacing of fasteners on single shearing properties of steel-to-timber joints with lag screws (in Japanese). Kozo Kogaku Ronbunshu B 59B:537–543Google Scholar
- 10.Wakashima Y, Shimizu H, Fujisawa Y, Ishikawa K, Kitamori A, Matsubara D (2016) High damping shear walls using wood friction joints. In: Proceeding of world conference on timber engineering, Vienna, AustriaGoogle Scholar
- 13.Architectural Institute of Japan (2006) Standard for structural design of timber structures (in Japanese). Architectural Institute of japan, Tokyo, pp 373–375Google Scholar
- 14.Murakami S, Jung K, Nakatani M, Kitamori A, Komatsu K (2010) Study on the pull-out performance of the screw type fasteners (in Japanese). In: Summaries of technical papers, annual meeting of the Architectural Institute of Japan: structure system, pp 189–190Google Scholar