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The twenty-first century is one of the most complex in the history of humanity, mainly due to the ecological crisisit is going through. The construction sector generates about 40% of CO2 emissions into the environment; the foregoingshould motivate this sector to seek new alternatives to develop new building practices. Taking these current needs intoaccount, this document classifies and presents a multidisciplinary solution that integrates biology, engineering andarchitecture to develop a new and innovative lightweight timber structure; it divides with a main structure made oftimber and an innovative joint system made of bio-polymers connecting all the panels. Through the study of diatoms,it was able to analyze the bio-morphology of the structure, joints and in particular the geometry since they were theinspiration for the design of this structure that presents an innovative and novel design of structural optimization.Through parametric design and digital fabrication, it was able to create a complex geometry that obtains excellentstructural behavior. This research discusses and explores how materials, geometry led to the optimization of a structureand how new structures can arise, thanks to biology new solutions can be obtained that are completely sustainable,being a clear example of how to combat the effects of the climate change and in a precise way it highlights theadvantages of the bio-design in the architectural design.

Timber connection capacity, in case of beam-column joint connection provides significant impact on the wooden building structures. Strength and stiffness of timber connections using reinforcement technique of wooden building structures have not been studied intensively. This paper studies the use of nails and modified-washer to improve wood connection’s performance. The experimental tests were conducted in the laboratory by comparing the partial connection between test specimen timber without reinforcement (standard type) and the reinforcement (PRP type). The testing was conducted based on partial connection beam-column joint test using Universal Testing Machine’s with a modified holder. Wood studied includes Meranti (Shorea spp.) and Mersawa (Anisoptera spp.). PRP type connection was using nails and modified-washer strengthening, and standard type connection was using a classic washer. Parameters studied were strength and stiffness of the connection, reviewed both: proportional limit load and ultimate limit load conditions. Result obtained from this research indicates that the use of nails and modified-washer make a positive contribution to improving the performance of the beam- column timber joint connections, in terms of strength capacity (both of proportional limit and ultimate limit loads) and stiffness capacity (displacement ductility ratio). Meranti beam-column timber joint is more brittle than Mersawa beam column timber joint, it has an impact on the results. PRP-type of Mersawa timber connection produces a higher ductility than the standard type, while the PRP-type of Meranti timber connection produces a similar ductility to the standard type.

Batak Karo is one of the ethnic group that exists in North Sumatra. Wooden house of Batak Karo called with Siwaluh Jabu. This wooden house has a structure system of pillars on top of stone foundations. This type of foundation is able to improve the performance of the overall structure due to lateral style caused by the earthquake. This research was conducted to know the behaviour of the structure of a wooden Batak Karo home especially the restoration of wooden style joints by comparing the results of a laboratory test, numerical analysis and analysis with SAP2000. Experimental testing in the lab do the test objects as much as 3 pieces. Testing by giving a cyclic load with a capacity of 10 tons in each of the test object to damaged object. Then conduct an evaluation the behavior of the structure consist of failure modes and moment-rotational angle relationship. After the experimental test was completed, the analysis continued with validate test results with laboratory of numerical analysis. Then conducted an analysis of the power structure by using SAP2000 program to know the power of elements against the maximum tension. The analysis conducted on the overall structure of the system and the structure of mast above the foundation stone. The program was conducted with input data: the work load, etc. As the output from these programs is the element force, etc. The final results of this program are the weaknesses and advantages of structural system observed from wooden Batak Karo.

The paper presents the development of numerical modeling for a traditional dovetail timber joint. The objective is to find the influence of its geometrical properties on the mechanical stiffness of the joint as well as to assess the main problems and limitations faced during the numerical modeling of the structure. An experiment with a replicated timber joint was used to validate the model. Material properties were ascertained and contact adjustment was made. Parametric study was performed: two angles of the joint beams were varied. Suitable ranges of the angles for each type of loading were found. Main limitations and problems present in the modeling are depicted in the discussion.

This paper analyses the optimisation studies of a pre-stressed embedment-type timber joint system, the Kusabi–Nageshi (K–N) timber joint system, designed to be used for structures in seismic-prone countries. The K–N joint is composed of a triangular-sectioned beam and wedges in combination with bolts. Its resistive mechanism utilises the embedment strength of timber and the pre-stress in association with friction. In addition, elastic energy deposited in the bolt as storage fills the gap as it is deformed during the embedment. With the aim of optimising both mechanically and physically, several alterations were tested in terms of shape (taper angle) and of combining densified veneer wood (DVW) with the joint members. A cyclic loading test of the cross joints was made to examine their structural behaviour. The use of less tapered wedges showed higher stiffness and strength, but the beam beneath was undesirably embedded. Different combinations of reinforcement with densified veneer wood showed that the use of the wedges alone provided high optimisation, and an increase in bolt axial force. The successful test results observed in the alteration using the densified veneer wood are expressed using the ‘analytical K–N joint diagram', an analytical method modified from a conventional joint diagram used in mechanical engineering, which showed itself to be an applicable method to predict the trend of the altered K–N joint. The use of the new tapered angle and densified veneer wood for optimisation, and the performance predictions using the analytical K–N joint diagram, will need further precise investigations but their great benefits are potentially promising.

Embedment is a key feature of timber joints envisioned as the ultimate solution in avoiding the devastating full collapse of timber structures in seismic countries. The Japanese traditional timber post-and-beam structural system utilizes moment-resisting joints based on embedment. Despite the joint's advantages having the ductile and energy-absorptive behavior continuously to the post-elastic phases, a primary shortcoming needs to be resolved - specifically of having the low and unreliable initial stiffness due to the gap formation between the contacting members. Further, large-dimensioned timber most suitable for the embedment-type joint is scarce and the lower quality of available timbers is making the modern applications difficult. A new timber joint capable of sustaining future seismic impacts is being pursued using various approaches. As a result of the optimization to satisfy the manifold studies, two traditional elements, namely Kusabi wedge and side-penetrating Nageshi beam, are combined and tightened by the penetrating steel bolt. Its tightening system eliminates the gap formation in the joint, and heightens its performance over the traditional embedment-type joints. Additional features, such as the damage-inducing and fast seismic-retrofitting ability, are also integrated. This new proposal for the Kusabi-Nageshi (K-N) timber joint system aims to provide a new alternative to the joints used in seismic countries.

We, in this article, propose a manual calculation method for the skeleton curb of single bolted timber joint. The calculation method takes into account the edge distance, the end distance, and the slenderness ratio as the parameters. The validity of the proposed calculation method was confirmed by the experimental results, the edge distance of 1d, 2d, 4d, 6d, 7d, the end distance of 1d, 2.5d, 4d, 7d, 10d, the slenderness ratio of 0.625 d, 3.75d, 7.5d, 10d.

We, in this article, propose a manual strength calculation method of single bolted timber joint loaded parallel to the grain. The strength calculation method takes into account the edge distance, the end distance, and the slenderness ratio as the parameters. The validity of the proposed calculation method was confirmed by the experimental results, the edge distance of 1d, 2d, 4d, 6d, 7d, the end distance of 1d, 2.5d, 4d, 7d, 10d, the slenderness ratio of 0.625d, 3.75d, 7.5d, 10d.

Widely used for light frame structures or for heavy laminated wood structures, dowel-type fasteners are the most commonly used kind of connectors in timber construction. The purpose of this work is to develop a tool for the semi-rigid analysis and design of such joints. Firstly, interests and approaches described in literature for the semi-rigid modeling of timber plane frames are summarized. Secondly, for a better understanding of the problem, the main characteristics of wood used as a structural material are presented. Finally, a method for an efficient study of joints built with dowel-type fasteners is proposed and developed. This method consists of the introduction of a specific finite element called “Finite Semi-Rigid Element (FSRE)” between the ends of the jointed members. This joint element consists of two nodes, each with three degrees of freedom. These nodes will be tied with common beamelements during the FE analysis. The stiffness of the FSRE is computed from the geometry of the joints and embe...

本研究では，一般的な褐色腐朽菌であるオオウズラタケ（Fomitopsis palustris）を用いて強制腐朽処理を行ったトドマツ（Abies Sachalinensis）の縦圧縮試験および鋼板添え板釘打ち接合の一面せん断試験を実施した。また試験終了後に鋼製ピンの衝撃打ち込み深さを測定した。試験の結果，腐朽初期の釘せん断耐力の低下は，縦圧縮強度の場合に見られるような指数曲線的な急激な減少とは異なる傾向を示していた。また腐朽した釘接合部では，釘頭部の破断が生じずに釘が引き抜ける破壊形態であったため，最大耐力に達した後は荷重がゆるやかに低下しながら変形が進行していった。鋼製ピンの衝撃打ち込み深さから推定した木材の支圧強度を用いてヨーロッパ型降伏理論に基づいて求めた釘せん断耐力の低下傾向を実験結果と比較した結果，腐朽した釘接合部の終局せん断耐力を，ピン打ち込み深さから評価することが可能であると示唆された。

This paper presents a new paradigm that is possible to aid the traditional experimental analysis in timber joints research. Laboratory experiment has incurred a lot of cost and times to find optimize end distance of a timber joint. Particle swarm optimization (PSO) is applied and tested focusing on a single shear timber joints. The determination of fitness function is based on the findings from the previous datasets of the traditional laboratory experiments. The dataset includes the timber species of Kapur that emphasizes on 2D and 3.5D in diameter of end distance. Several PSO parameters were tested to find the maximum load carrying capacity of timber joint for different end distances. The findings show that PSO can give a feasible solution for a single shear strength timber joint performance. It demonstrates that the PSO has a potential to be used as a timber joint simulations that would be beneficial to timber joint researchers in predicting the load carrying capacity of a joint and contributes in reducing time and cost.