Analytical study and finite element modelling of timber connections with glued-in rods in bending

Abstract The behaviour of glued-in ribbed steel bars in timber beam-to-beam connections has been analysed experimentally and numerically. The experimental results exhibit two different failure modes due to the internal stiffness distribution between steel and timber in bending. They are used to validate a 3D finite element model developed considering the actual geometry of the connections. This model considers the elasto-plastic behaviour of steel and the orthotropic elasto-plastic behaviour of timber. Timber plasticity is considered for compression in parallel and perpendicular to grain directions. The compression arises mainly in the local contact zone between the connected timber beams and in the vicinity of the glued-in rods. These sources of non-linearities, due to the elasto-plastic behaviour and the contact, control partially the load-carrying capacity of the connections. To take account of the quasi brittle behaviour of timber in shear and tension perpendicular to grain, a failure criterion is used. The numerical results show a good agreement with the experimental results. In addition, analytical models are proposed to predict the initial stiffness and the ultimate moment of the glued-in rods connections. The comparison of the analytical and the numerical results shows the good capability of the analytical model to be used as a design approach for the glued-in rod connections.

[1]  Emilio Martín Gutiérrez,et al.  Model for predicting the axial strength of joints made with glued-in rods in sawn timber , 2010 .

[2]  M. Taazount,et al.  Numerical 3D finite element modelling and experimental tests for dowel-type timber joints , 2009 .

[3]  J. Estévez Cimadevila,et al.  Experimental behaviour of threaded steel rods glued into high-density hardwood , 2007 .

[4]  René Steiger,et al.  State-of-the-art review on timber connections with glued-in steel rods , 2011 .

[5]  Erik Serrano,et al.  Fracture mechanics in timber engineering – Strength analyses of components and joints , 2007 .

[6]  P. Racher,et al.  Analysis of dowelled timber to timber moment-resisting joints , 2007 .

[7]  Y. Iijima,et al.  Axially loaded glued-in hardwood dowels , 2001, Wood Science and Technology.

[8]  Erik Serrano,et al.  Glued-in rods for timber structures - a 3D model and finite element parameter studies , 2001 .

[9]  P. Racher,et al.  Effect of web stiffness on the bending behaviour of timber composite I-beams , 2007 .

[10]  M. Taazount,et al.  Numerical and experimental analyses of multiple-dowel steel-to-timber joints in tension perpendicular to grain , 2009 .

[11]  Per-Johan Gustafsson,et al.  Shear strength of beam splice joints with glued-in rods , 2003, Journal of Wood Science.

[12]  R. P. Johnson,et al.  General rules and rules for buildings , 2004 .

[13]  Marie Johansson,et al.  Design of Timber Structures , 2011 .

[14]  M. Piazza,et al.  Axial glued-in steel timber joints—experimental and numerical analysis , 2004, Holz als Roh- und Werkstoff.

[15]  Chanakya Arya,et al.  Design in timber to BS 5268 , 2009 .

[16]  R. Brandner,et al.  Glued laminated timber in bending: new aspects concerning modelling , 2008, Wood Science and Technology.

[17]  Erik Serrano,et al.  Glued-in rods for timber structures—An experimental study of softening behaviour , 2001 .

[18]  J. A. Cabezas,et al.  Reduction of perpendicular-to-grain stresses in the apex zone of curved beams using glued-in rods , 2010 .

[19]  Stephen Gilbert,et al.  Behaviour of joints with bonded-in steel bars loaded parallel to the grain of timber elements , 2011 .

[20]  O. Hoffman.  The Brittle Strength of Orthotropic Materials , 1967 .

[21]  R. Widmann,et al.  Pull-out strength of axially loaded steel rods bonded in glulam parallel to the grain , 2007 .

[22]  A. Rossignon,et al.  Experimental assessment of the pull-out strength of single rods bonded in glulam parallel to the grain , 2008, Holz als Roh- und Werkstoff.

[23]  Pierre Morlier,et al.  Geometric parameters which affect the short term resistance of an axially loaded glued-in rod , 2007 .