Strength parameters for fasteners determined in accordance with the methods prescribed for the European CE-marking leads to quite different values for seemingly similar products from different manufactures. The results are hardly repeatable, to some extent due to difficulties in selecting representative timber samples for the testing. Beside this uncertainty, the declared values available to the designer concerns only structural timber, so no strength parameters are available for common engineered wood products such as LVL or plywood
Wooden constructions are on the rise again – encouraged by a strong trend towards sustainable and resource efficient buildings. Load-bearing timber-glass composite elements – a novel concept to use the in-plane loadbearing potential of glass – could contribute to a more efficient use of materials in façades. The current study relates to...
In this paper, the relations between the load-deformation property of the CLT connections and the seismic performance of the 3 story CLT construction are analytically discussed. The static and the dynamic properties of the CLT connections led each from the static and the dynamic tests were obviously different, however the analytical results based on these properties were agree each with the results of the static and the dynamic tests proving the adequateness of estimated properties. The further study on the dynamic effects of CLT connections is necessary.
Timber structures are strongly depending on the design of connections, which are mostly constructed from steel components. However, these joints have a number of limitations such as the tendency to be heavy, proneness to corrosion and often poor aesthetic appearances. Therefore, this study aims to replace metallic joints by non-metallic materials. An experimental testing program was performed to investigate the use of glass fiber reinforced plastics (GFRP), densified veneer wood (DVW) and laminated veneer lumber (LVL) in the form of plates and dowels in different test configurations. Analytical and numerical models were developed to better understand the load-bearing behaviour and to perform static verifications. The models were validated based on the experimental results. The results demonstrate that the use of GFRP dowels in combination with GFRP plates can provide a robust connection system for contemporary applications.
The fracture characteristics and deformation ability in timber engineering is very important criteria for structural design. However those fracture patterns are complex and confusing, so the quantitative evaluation is very difficult. In our past study, we could see the three fracture types and defined them the brittle, ductile and inter-mediate type with bolted connections loaded perpendicular to the grain. This definition isn’t enough because it’s not clear definition and we couldn’t study the deformation ability or ductility factor.In this study, for those connections, we would apply the evaluation method proposed by Ian et al. In this evaluation method, fracture pattern would have relevance to ductility factor. And the evaluation methods proposed by us, AIJ code and Ian et al would be compared. As a result, it is confirmed that fracture pattern based on mechanical calculation proposed by Ian could be agree with the pattern based on our video observation. Then proposed method would be useful for structural design.
The paper describes experimental and numerical analyses on a completely new connection system developed for CLT (Cross Laminated Timber) constructions. The innovative solution herein proposed, named X-RAD, consists of a point-to-point mechanical connection system, fixed to the corners of the CLT panels. This connection, that is designed to be prefabricated, is made of a metal wrapping and an inner hard wood element which are fastened to the panel by means of allthreaded self-tapping screws. Such system permits to reduce significantly the number of bolts/fasteners required to assemble two or more panels together or to connect them to the foundation. This results in the enhancement of the installation process in terms of speed, quality and safety. One of the reasons that fuelled the development of the presented system, is the desire of offering a solution to those issues (e.g. to satisfy ductility and energetic dissipation requirements) commonly related to the seismic safety of timber structures. In other words there was the will of defining a system able to guarantee an adequate level of ductility and energetic dissipation.
Hybrid composite glulam timber reinforced using deformed steel bars and epoxy resin adhesive (RGTSB), was significantly developed in Kagoshima University. In this paper, a beam-to-beam connection for RGTSB and experimental data on the connection are presented. Two 2:3-scaled simply-supported beams under four-point flexural bending in short-term loading, connection elements under short and long-term tension loading were tested. The connection for RGTSB beam performed on bending behaviour such as non-connection RGTSB beam, especially better on ductility.
In a current research project the gluability of various soft- und hardwood species and their applicability in glued laminated timber are investigated. The influence of the processing parameters on the delamination resistance and shear strength of the glue lines are presented in this work.
The bonding forces, which are necessary for the integrity of a glue line, act in the interface within a distance that varies from nanometers to micrometers. The parameters that may have significant influence on the bonding strength and durability of adhesive joints are numerous and depend on the type of wood, adhesive and processing conditions.