International Conference on Innovative Materials, Structures and Technologies
September 30-October 2 2015, Riga, Latvia
Cross laminated timber (CLT) is one of the structural building systems based on the lamination of multiple layers, where each layer is oriented perpendicularly to each other. Recent requirements are placed to develop an alternative process based on the mechanical lamination of the layers, which is of particular interest to our research group at the University Centre for Energy Efficient Buildings. The goal is to develop and verify the behaviour of mechanically laminated CLT wall panels exposed to shear stresses in the plane. The shear resistance of mechanically jointed CLT is ensured by connecting the layers by screws. The paper deals with the experimental analysis focused on the determination of the torsional stiffness and the slip modulus of crossing areas for different numbers of orthogonally connected layers. The results of the experiments were compared with the current analytical model.
Cross laminated timber (CLT) has become very popular for all types of structures all around the world in last years. CLT consists of uneven number of plank layers oriented in 90° angle to each other and bonded together. Various types of adhesives and technologies are used for bonding and manufacturing of final product. In some cases, gluing is not ideal manufacturing method and there is a demand of other manufacturing processes. Mechanical jointing is logical result of current research at the Czech Technical University. Research is focused on developing and verifying mechanical behaviour of mechanically jointed CLT solid wood panels. Sets of experiments focused on mechanical behaviour of these mechanically jointed CLT panels were performed. This paper summarizes results of wall, floor and timber-concrete composite elements, which have been tested.
Twenty real dimensions beams from the glued laminated timber were tested in our previously works. Twenty advanced FE models were created precisely according to tested beams. Input files for FE models are lengths of segments and local moduli of elasticity. The segment is part of lamella between two finger joints. Each local modulus of elasticity was obtained via non-destructive penetration test. The output for comparison between real beam and FE model is displacement in half span. The quality of input data file from experiments is very important for the good agreement between real tested beams and FE models. In advanced FE models is described distribution of local moduli of elasticity via distribution function. The solution is based on the LHS. Accuracy of each distribution function is dependent on the number of measured local moduli of elasticity. In presented work was used probabilistic approach for determination of corresponding number of penetration tests as function of segments lengths. Results of this analysis will be used in the latter series of bending tests of new real dimensions beams and corresponding advanced FE models.
This paper deals with behavior of timber-concrete composite structures with mechanical connection systems. The paper is focused to two different connection systems: using dowel-type fasteners and using special surface connector. Analytical model of dowel-type connection system is based on modification of Johansen´s equations valid for timber to timber connections. Behavior of connection system with special surface connector is evaluated by experiments and numerical simulations. The paper deals also with the evaluation of structural timber and the determination of the performance of structural timber elements.