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 present paper evaluate slaminatedcarbonbi-wove fibers Reinforced with vinyl ester composites. Vinyl ester was used as a matrix to prepare composites by in situ polymerization technique. Four planar layers were made simultaneously by keeping one over the other and each layer made sure to be weighed off by 15% which was maintained in all layers with different orientations. Pre-assumed Layer-1 is (50/50)50%,0º; Layer-2 is (35/35/30) 35% 0º, 35% +45º,30%,0;Layer-3is (25/50/25) 25% 0º, 50%+45º,25-45º; and Layer-4is (25/25/25/25) (25% 0º, 25% +45º,25% -45º,25% 90º.The composite was prepared with the help of hand layup technique. Test ready specimens were tested with the help of shearing machine in accordance with ASTM Standards .It was observed that vinyl ester made good interface with parent fiber material. Flexural strength and Tensile strength have improved up to 3rd layer and decreased afterwards whereas Flexural modulus and Tensile modulus have linearly increased up to 4th layer. Thermal stability and Glass transition temperature have also been found to be satisfactory for all the laminated layers. Chemical resistance was good for the entire chemicals except sodium hydroxide.
In Japan, the moment resistance connections of large-scale timber building are inefficiency in terms of time and economic, because connections and column base hardware are custom-made to obtain the required performance. To improve this problem, it is necessary to unify standardization of their connection. At first, in this study, we focused on column-base connection, the horizontal...
A concrete-filled steel tube (CFT) column system has many advantages compared with ordinary sttel or reinforced concrete system. One of the main advantages is the interaction between steel tube and concrete: occurrence of the local buckling of steel tube is delayed by the restraint of concrete, and the strength of concrete is increased by the confining effect provided from the steel tube. Extensive research work has been done in Japan over the last 15 years, including "New Urban Housing Project" and "US-Japan Cooperative Earthquake Research Program", in addition to the work done by individual universities and industries, which has been presented at the annual meeting of Architectural Institute of Japan (AIJ). This paper introduces the merits, design provisions and recent construction trends of CFT column systems in Japan, and discusses the results of trial designs of CFT theme structures which have been carried out to look for the advantages in the performance and construction cost compared with other constructional system.
The paper presents some experimental data and phenomenon on bracket anchor connections for Cross-Laminated-Timber. The goal of this research is to provide a better understanding of the seismic performance of bracket connections subjected to seismic actions and how to choose and design bracket connections for Cross-Laminated-Timber structures. Test configuration and experimental setups are illustrated in details; cyclic displacement schedules of the connections in two directions are presented considering that CLT wall has horizontal sliding in the plane and uplift at the end in quasi-state tests. Different failure modes and force transmission mechanisms of different connections under the loading protocol were analysed. And important quantities for seismic design such as strength, and stiffness, equivalent yield load, peak load and ductility of the connections are evaluated and compared among different kinds of connections; an excellent connector is revealed in ductility and load capacity by test data analysis. In addition, some suggestions to choose and design bracket anchor connections are given.
Recently, the Japanese government enacted a new law in order to promote large wooden building. As a result, the momentum in the construction of large wooden building especially multi-stories wooden buildings in local area has been growing rapidly. In order to achieve these buildings, the higher structural performances than that by usual technique are required.GIR joint system is widely adapted for the joint part of wooden structures. Glued in rod joint-system(GIR) have high strength and high rigidity compared to existing joint-system. On the other hand, the structural LVL with the flexibility performance of cross-section and high structural performance is expected as a material for multi-stories wooden building. So, in this study, the pull-out tests of GIR joints inserted to structural LVL are carried out. And structural characteristics of this type of joint is discussed. Maximum strength and allowable load for temporary loading obtained by pull-out tests are presented.