Shear Connections with Self-Tapping Screws for Cross-Laminated Timber Panels

Cross-Laminated-Timber (CLT) is increasingly gaining popularity in residential and non-residential applications in North America. To use CLT as lateral load resisting system, individual panels need to be connected. In order to provide in-plane shear connections, CLT panels may be joined with a variety of options including the use of self-tapping-screws (STS) in surface splines and half-lap joints. Alternatively, STS can be installed at an angle to the plane allowing for simple butt joints and avoiding any machining. This study investigated the performance of CLT panel assemblies connected with STS under vertical shear loading. The three aforementioned options were applied to join 3ply and 5-ply CLT panels. A total of 60 mid-scale quasi-static shear tests were performed to determine and compare the connection performance in terms of strength, stiffness, and ductility. It was shown that - depending on the screw layout - either very stiff or very ductile joint performance can be achieved.

[1]  M. Fragiacomo,et al.  Behaviour of Cross-Laminated Timber Panels under Cyclic Loads , 2014 .

[2]  Bertil Enquist,et al.  Experimental study of cross-laminated timber wall panels , 2009, European Journal of Wood and Wood Products.

[3]  R. Brandner,et al.  Cross laminated timber (CLT): overview and development , 2015, European Journal of Wood and Wood Products.

[4]  Bezaleel S. Benjamin,et al.  Deflections of Structures as Specified by the National Design Specification for Wood Construction , 2004 .

[5]  C. Sandhaas,et al.  Quasi-static and pseudo-dynamic tests on X-lam walls and buildings , 2006 .

[6]  BenjaminWard Richardson.  Examination of the Lateral Resistance of Cross-Laminated Timber in Panel-Panel Connections , 2015 .

[7]  Roberto Tomasi,et al.  Theoretical and experimental analysis of timber-to-timber joints connected with inclined screws , 2010 .

[8]  Frank Lam,et al.  Self‐tapping screws as reinforcement for rounded dovetail connections , 2009 .

[9]  C. Sandhaas,et al.  SOFIE Project - Cyclic tests on cross-laminated wooden panels , 2006 .

[10]  Thomas Lee Wilkinson.  Assessment of Modification Factors for a Row of Bolts or Timber Connectors. , 1980 .

[11]  Hans Joachim Blaß,et al.  Selbstbohrende Holzschrauben und ihre Anwendungsmöglichkeiten , 2003 .

[12]  Yu-Li Lin,et al.  Moment-Resisting Capacity of Bolt Connections in Japanese Cedar Structural Glulam Members , 2008 .

[13]  T. Tannert,et al.  Structural Design, Approval, and Monitoring of a UBC Tall Wood Building , 2017 .

[14]  M. Fragiacomo,et al.  Cyclic behavior of typical screwed connections for cross-laminated (CLT) structures , 2015, European Journal of Wood and Wood Products.

[15]  Ario Ceccotti,et al.  Analysis of X-lam panel-to panel connections under monotonic and cyclic loading , 2009 .

[16]  M Fragiacomo.  “Seismic behaviour of cross-laminated timber buildings: numerical modelling and design provisions.” , 2013 .

[17]  Hans Joachim Blaß,et al.  Self-tapping Screws as Reinforcements in Beam Supports , 2006 .

[18]  T. Wilkinson,et al.  Lateral and withdrawl resistence of tapping screws in three densities of wood. , 1970 .

[19]  H. Blass,et al.  Joints with inclined screws , 2002 .

[20]  Klavs Feilberg Hansen.  Mechanical properties of self-tapping screws and nails in wood , 2002 .

[21]  A.J.M. Jorissen,et al.  DOUBLE SHEAR TIMBER CONNECTIONS WITH DOWEL TYPE FASTENERS , 1998 .

[22]  Hans Joachim Blaß,et al.  Screws with continuous threads in timber connections , 2001 .

[23]  Gerhard Schickhofer,et al.  In Plane Shear Strength of Cross Laminated Timber (CLT): Test Configuration, Quantification and Influencing Parameters , 2013 .

[24]  Gernot Pirnbacher,et al.  Base Parameters of self-tapping Screws , 2009 .

[25]  Thomas Tannert,et al.  Cross-Laminated Timber Shear Connections with Double-Angled Self-Tapping Screw Assemblies , 2016 .

[26]  Reinhard Brandner,et al.  Group action of axially-loaded screws in the narrow face of cross laminated timber , 2016 .

[27]  John J. Zahn,et al.  Design Equation for Multiple‐Fastener Wood Connections , 1991 .

[28]  Naohito Kawai,et al.  SOFIE project – 3D shaking table test on a seven‐storey full‐scale cross‐laminated timber building , 2013 .

[29]  Ario Ceccotti,et al.  Cyclic Behavior of CLT Wall Systems: Experimental Tests and Analytical Prediction Models , 2015 .

[30]  Gerhard Schickhofer,et al.  Withdrawal resistance of self-tapping screws in unidirectional and orthogonal layered timber products , 2015 .

[31]  H. J. Larsen,et al.  Eurocode 5 - Design of timber structures: Joints , 1993 .

[32]  H. Blass,et al.  Design of solid wood panels with cross layers , 2004 .

[33]  R. Tomasi.  A new ductile approach design of joints assembled with screw connectors , 2006 .

[34]  Massimo Fragiacomo,et al.  “Experimental cyclic tests on cross-laminated timber panels and typical connections.” , 2011 .

[35]  Philipp Dietsch,et al.  Self-tapping screws and threaded rods as reinforcement for structural timber elements – A state-of-the-art report , 2015 .

[36]  Michael Fairhurst,et al.  Ductility Estimation for a Novel Timber–Steel Hybrid System , 2016 .

[37]  Min-Chyuan Yeh,et al.  Investigation of the structural performance of glulam beam connections using self-tapping screws , 2013, Journal of Wood Science.

[38]  Calvin O. Cramer.  Load Distribution in Multiple-Bolt Tension Joints , 1968 .

[39]  H. Blass,et al.  Models for the calculation of the withdrawal capacity of self-tapping screws , 2009 .

[40]  John W. van de Lindt,et al.  An Overview of CLT Research and Implementation in North America , 2016 .

[41]  浩一 楠,et al.  保有水平耐力計算とInternational Building Codeの比較と検討 , 2014 .

[42]  Ario Ceccotti,et al.  New Technologies for Construction of Medium-Rise Buildings in Seismic Regions: The XLAM Case , 2008 .

[43]  A. Frangi,et al.  Fully Threaded Self-tapping Screws Subjected to Combined Axial and Lateral Loading with Different Load to Grain Angles , 2014 .

[44]  B. R Ellis,et al.  Dynamic testing and stiffness evaluation of a six-storey timber framed building during construction , 2001 .

[45]  K. W. Johansen,et al.  Theory of Timber Connections , 1949 .

[46]  Simona Klobčar,et al.  Influence of openings on shear capacity of wooden walls , 2005 .

[47]  Andrea Frangi,et al.  Design model for inclined screws under varying load to grain angles , 2014 .

[48]  Andrea Frangi,et al.  Experimental analysis of cross-laminated timber panels in fire , 2009 .

[49]  G. Lantos.  Load distribution in a row of fasteners subjected to lateral load , 1969 .