共查询到20条相似文献，搜索用时 109 毫秒
1.
Ciprian Pîrvu Hiroaki Yoshida Masahiro Inayama Motoi Yasumura Kinji Taki 《Journal of Wood Science》2000,46(3):193-201
In past years high priority was given to developing a seismic design for wood structures, including research on the response of wood structures to earthquakes. In this study a new type of portal frame with relatively large span was developed for the traditional Japanese wooden houses with large openings at the front to strengthen the structure. Stainless steel plates coated with zinc and glued with epoxy adhesives on laminated veneer lumber (LVL) members, composed of Douglas fir veneer and bonded with phenolformaldehyde resin, were used. The connection between the frame's beam and columns and between the columns and groundsills was mechanical, with bolts. The subject of this research was to analyze strength properties and failure behavior of glued LVL metal joints used as structural components and to evaluate the response of LVL portal frames under cyclic lateral loading. The results show that portal frames using glued LVL metal plates have a good multiplier for the shear walls and may be applied to traditional Japanese structures. The equivalent viscous damping provided good energy dissipation in the frames. The joints displayed good mechanical behavior during tests; moreover, the structures demonstrated high strength, stiffness, and ductility, which are necessary for a seismic design.Part of this paper was presented at the 47th annual meeting of the Japan Wood Research Society, Kouchi, April 1997; and at the 5th world conference on timber engineering. Montreux, Switzerland, August 1998 相似文献
2.
Chun-Young Park HyungKun Kim Chang-Deuk Eom Gwang-Chul Kim Jun-Jae Lee 《Journal of Wood Science》2014,60(1):30-38
This study is aimed to evaluate whether lintel has structural effect because it has not been categorized as a structural member. This study experimentally evaluated the horizontal load-carrying capacity of post-beam timber frame structures with bi-linear model and energy dissipation mechanism. To evaluate the effect on horizontal performance of lintel which has been widely used as wall frame in Korean traditional post-beam structure, two frames were tested in different types. One had no lintel and the other one had lintel at the height of 800 mm, respectively. Cyclic loading tests were conducted for each frame according to the standard loading protocol. Frame which had lintel showed slightly higher stiffness. And it showed noticeably significant energy dissipation performance after yield point of the joint. And that leads to the conclusion that lintel has structural effect and it should be considered as an important factor when evaluating horizontal performance of the structure after yield point of the joint. 相似文献
3.
为研究空心胶合木梁柱式结构体系抗侧力性能,对纯框架及框架-人字撑两种单跨结构试件进行了单调及低周反复加载试验,考察了结构破坏模式、耗能能力、刚度等抗震性能。结果表明:纯框架与框架-人字撑结构均具有一定抗侧力性能,但纯框架结构承载能力较弱,不建议单独用于工程实践;框架-人字撑结构具较大抗侧刚度及承载力,分别为纯框架的6.3倍及2.68倍,但其延性仅为纯框架的67%。两种结构失效前强度退化小于30%,具足够剩余承载力。 相似文献
4.
5.
在木家具结构设计中,特别是具有中国传统家具风格的实木家具结构设计中,木框角部斜角榫接合强度是人们既关注又无法回避的问题。抗拉强度和抗弯强度是衡量木框斜角榫接合性能高低的两个重要指标。笔者对三种常用的、易于机械加工的斜角榫接合试件的强度(抗拉强度,抗弯强度)进行了实验测定,并从各个方面对其进行比较、分析。研究结果表明:斜角榫接合形式,胶黏剂种类,加压时间等各个因子都不同程度地影响着木框角部接合的整体结构性能。单肩斜角明榫接合效果最好。 相似文献
6.
Compressed wooden plates and dowels were used to connect members in post-and-beam structures as a substitute for a steel fastener.
In order to take advantage of the characteristic properties of compressed wood and to achieve optimum joint performance, two
compressed wooden plates were used in each joint to give multiple shear planes for each compressed wooden dowel. Consequently,
this type of joint showed very good properties in pull-out and momen-trotation performance, and its engineering design could
be further optimized. This joint is expected to be introduced to many kinds of structural systems, including long-span frame
structures made of domestic timber found in Japanese residential houses. 相似文献
7.
Analysis and design of furniture frames 总被引：2，自引：0，他引：2
Summary The engineering design of furniture frames was investigated. The stiffness method of matrix structural analysis was applied to furniture frame design, and modifications of it which are needed to treat frames with semi-rigid, elastically non-linear joints of finite size were developed. A method of designing two-pin moment-resisting dowel joints was also developed. An experimental furniture frame was designed using the theories formulated. Results of tests performed on this frame agreed satisfactorily with those predicted theoretically.
Journal Paper No. 3575 of Purdue University Agr. Expt. Station. 相似文献
Zusammenfassung Die technische Konstruktion von Möbelrahmen wurde untersucht. Ein Rechenverfahren zur Bestimmung der Steifigkeit wurde mit Hilfe der Matrizen-Analyse auf Möbelrahmen-Konstruktionen angewendet und entsprechende Abwandlungen, die zur Behandlung von Rahmen mit halbstarren, elastisch nicht-linearen Verbindungen bestimmter Größe benötigt werden, wurden entwickelt. Gleichzeitig wurde ein Verfahren zur Konstruktion von biegesteifen Doppel-Dübelverbindungen entwickelt. Ein Versuchs-Möbelrahmen wurde aufgrund der erarbeiteten Theorie gebaut. Die Ergebnisse aus den Versuchen mit diesem Rahmen stimmten weitgehend mit den hierfür theoretisch berechneten Werten überein.
Journal Paper No. 3575 of Purdue University Agr. Expt. Station. 相似文献
8.
《Wood material science & engineering》2013,8(3-4):131-139
Abstract The European yield model (EYM) has been accepted to determine the load-carrying capacity of structural timber connections. However, experiments of bolted connections are still not in agreement with the EYM unless the additional bearing capacity offered by the washers is taken into account. This bearing capacity is depending on the compressive strength perpendicular to grain of the structural timber. Tests results carried out with M16 and M24 washers on solid and glued laminated timber are used to verify the reliability of three strength capacity predicting models, one of which is an analytical model while the other two are empirical. It was concluded that the analytical model is the superior one. This model should be incorporated in all new structural timber design code revisions. 相似文献
9.
In Japan, the lifetime cycle of most housing lasts around 20–30 years. A governing factor in this respect is poor durability
due to old-fashioned use of the house. As a solution of this problem, houses can be built with a skeleton structure that allows
free partition of spaces by future owners. To develop the skeleton structure effectively, multistory frames with spans of
6 to 10 m are required. For this reason, attention has been focused on the behavior of multistory timber frame structures.
In this article, two types of wooden portal frame structures are proposed. Both structures have improved vertical columns
with short horizontal members glued in. The aim of this study was to investigate structurally effective solutions with these
types of columns. The first type of the new structure changed the location of the moment-transmitting ductile connection with
the improved columns. The second type of structure used an extended panel zone. Nine portal frame specimens were tested. The
stiffness values were improved by around 1.7 and 3.5 times when compared with the control, and the strength was improved by
around 1.25 and 1.45 times. 相似文献
10.
Pseudodynamic (PSD) lateral loading tests were conducted on conventional post and beam timber frames with plywood-sheathed
shear walls to validate the dynamic model of wall panels, each with an opening of a different configuration. The lateral forces
were applied step by step at the top of the wooden frames by the computer-controlled actuator, and the displacement response
for the next step was computed on the basis of the input accelerogram of the 1940 El Centro earthquake scaled up to 0.4g. The test results were compared with those of the lumped mass time-history earthquake response analysis using the hysteresis
model with pinching. The results of the dynamic analysis with this global model consisting of the envelope curves, unloading
and reloading with pinching agreed well with the experimental results of the PSD tests of this type of earthquake record.
Some parametric studies may be necessary, however, to validate the model with different earthquake records. The hysteretical
parameters obtained in this study showed similar values for each of the wall panels with different opening configurations.
This makes it possible to use the model and parameters for the plywood-sheathed shear walls to estimate the dynamic behavior
of entire structures without conducting expensive PSD tests or shaking table tests. 相似文献
11.
Andrea Frangi Marco Bertocchi Sebastian Clau? Peter Niemz 《Wood Science and Technology》2012,46(5):793-812
Finger joints are commonly used to produce engineered wood products like glued laminated timber beams. Although comprehensive research has been conducted on the structural behaviour of finger joints at ambient temperature, there is very little information about the structural behaviour at elevated temperature. A comprehensive research project on the fire resistance of bonded timber elements is currently ongoing at the ETH Zurich. The aim of the research project is the development of simplified design models for the fire resistance of bonded structural timber elements taking into account the behaviour of the adhesive used at elevated temperature. The paper presents the results of a first series of tensile and bending tests on specimens with finger joints pre-heated in an oven. The tests were carried out with different adhesives that fulfil current approval criteria for the use in load-bearing timber components. The results showed substantial differences in temperature dependant strength reduction and failure between the different adhesives tested. Thus, the structural behaviour of finger joints at elevated temperature is strongly influenced by the behaviour of the adhesive used for bonding and may govern the fire design of engineered wood products like glued laminated timber beams. 相似文献
12.
13.
介绍平台框架式木结构的结构形式,并对其设计方法进行探讨,在此基础上以一栋建筑面积30m2、单层框架式木结构房屋为实例,参照最新的木结构设计规范以及相关荷载设计规范,采用LRFD法对结构所承受的荷载以及主要构件进行设计。通过此设计实例,分析轻型木结构的设计步骤,提出一些我国在木结构设计和研究方面所存在的问题,为相关设计和研究人员提供参考。 相似文献
14.
为准确评价斜螺钉连接钢 木节点的剪切性能,探明其受力机理,以云杉胶合木、钢板和自攻螺钉作为研究材料,测试不同荷载方向与受力情况下斜螺钉连接节点的承载性能,将试验数据与国外规范中的计算模型进行对比,提高了侧边钢板 胶合木(钢 木)斜螺钉连接节点承载性能的预测能力。结果表明:自攻螺钉与剪切面之间的角度变化对其在钢 木节点承受剪 压复合应力的承载力影响不明显,当偏转为剪 拉复合应力时,节点承载力明显增大,并在30°~45°获得最大值;剪 压复合应力时,现行EC5公式计算剪 压节点的极限承载力非常不安全;EC5的刚度预测结果在剪 压复合应力区和垂直剪切面钉入时,与试验值吻合度很高,但对剪 拉区节点的滑移模量没有预测性;将Tomasi模型应用于斜螺钉连接钢 木节点滑移模量理论计算时,在45°~90°时与试验值吻合度极高。单颗自攻螺钉的抗拔刚度计算节点滑移模量的方法极为有效,具有较高的借鉴意义。 相似文献
15.
The inter-storey drift limitations are meaningful reference values for structural seismic performance evaluation. This paper presents an analytical investigation into the seismic performance of multi-storey cross-laminated timber (CLT) structures to obtain the drift limitations under different earthquake hazard levels reasonably. The Pinching4 model was used to simulate the nonlinear mechanical behavior of three types of connections used in CLT structures, and a numerical model was further developed to capture the lateral load-resisting properties of CLT shear walls. Moreover, three benchmark multi-storey CLT apartment buildings were designed using the Equivalent Static Force Procedure according to National Building Code of Canada (NBCC), and simplified structural models were developed for these buildings. Depending on the results from numerous time-history dynamic analyses, the empirical cumulative distribution functions (CDFs) of the maximum inter-storey drifts were constructed for the three benchmark buildings. The probability of non-exceedance (PNE) of inter-storey drift thresholds under different earthquake hazard levels was proposed and validated. It is recommended that for low-rise CLT buildings within three stories, values of 0.30%, 0.75%, and 1.40% can be considered as the drift limitations for frequent, medium, and rare seismic hazard levels, respectively. For mid-rise or high-rise buildings without three stories, 0.25%, 0.70%, and 1.30% can be considered as drift limitations. 相似文献
16.
Numerical analysis of furniture constructions 总被引：2，自引：0，他引：2
J. Smardzewski 《Wood Science and Technology》1998,32(4):273-286
Summary Trying to rationalize principles of furniture design and construction whose objective function is minimization of material use and maximization of the strength of elements and construction nodes, a research project was undertaken with the objective to work out, write and test the effectiveness of a program designed for rigidity-strength analysis of furniture side frames constructions. The program provides results of computation of values of cross section forces, node translocations and dimensions of connectors (dowels or tenons) in selected places of connection of component elements. It was found that tenon connections in constructions of chair side frames ensure sufficient strength and rigidity of the system and maintain optimal dimensions of cross sections of component elements. Dowel connections can replace tenon joints reaching the same strength, but the areas of cross sections of the elements to be joined will have to increase from 18 to 45%. The strength of connections and their dimensions do not constitute the function of the position of the connecting member in the chair and the rigidity of the chair side frame depends directly on the position of the connecting member and increases as the position of this element is lowered. The developed computer program allows accurate, rapid and multiple rigidity-strength analysis of furniture frame constructions made of wood. 相似文献
17.
The shear strength of dowel-type timber connections with multiple slotted-in steel plates was estimated based on European
yield theory. The values calculated based on the yield theory were compared with experimentally obtained results. An experiment
was performed on dowel-type timber connections with two and three slottedin steel plates under lateral loads parallel to the
grain. The yield mode of the dowel-type connection assumed in this study corresponds approximately to the failure mode of
the connection obtained from the experiment. The shear strength of the dowel-type connections calculated based on the yield
theory showed good agreement with the results for shear strength obtained in the experiment. The yield theory was useful for
estimating the shear strength of the doweltype connection with multiple slotted-in steel plates. The shear strength of the
dowel-type connection was greatly affected by the spacing of the steel plates, the number of steel plates, and the timber
thickness. The values of these parameters that showed the proper shear strength of the dowel-type connection could be estimated
based on the yield theory.
Part of this paper was presented at the 9th Timber Engineering Forum of the Japan Timber Engineering Society, December 2005 相似文献
18.
J. C. M. Schoenmakers A. J. M. Jorissen A. J. M. Leijten 《Wood Science and Technology》2010,44(4):579-595
Different test setups for determining perpendicular to grain embedment strength of timber have been reported in literature.
In addition, different definitions of strength have been used associated with the deformation level underneath the fastener.
It is shown that all reported experimental results can be related, which enables comparison on a common basis. Furthermore,
several models for embedment strength perpendicular to the grain which primarily depend on timber density (specific gravity)
and fastener diameter are evaluated. It is shown that the model currently prescribed by the European structural timber design
code [Comité Européen de Normalisation (CEN) EN 1995-1-1: 2004: Eurocode 5—design of timber structures. Part 1.1: general
rules and rules for buildings. CEN, Brussels, 2004] is unable to accurately predict the strength and an alternative is proposed. This may result in more reliable timber connections
in applying the European Yield Model to determine the connection strength. 相似文献
19.
Strength grading of Norway spruce structural timber: revisiting property relationships used in EN 338 classification system 总被引：1，自引：0，他引：1
Solid timber for structural applications has to be strength graded prior to its use. In order to remain economic the grading process usually focuses on the most important physical and mechanical properties: density, modulus of elasticity (MOE) and bending strength. Based on respective limits given in standards, the timber is assigned to strength classes. Additional mechanical properties such as tensile and compression strength parallel to the grain are derived from the basic property values by empirical relationships. The objective of this study was to review some of these property relationships based on recently compiled large data sets as a contribution for a future revision of the grading standards. Based on mechanical tests of Norway spruce structural timber with different cross-sections, the following characteristic values and property relationships were evaluated: (a) strength and MOE in bending, (b) in-grade characteristic values of bending strength, bending MOE and density, (c) relationship of characteristic values of tension and compression strength parallel to the grain with respect to the corresponding characteristic value of bending strength, (d) ratio of fifth percentiles and mean values of density and MOE, as well as (e) the ratio of MOE in bending, tension and compression. Mechanical tests were accompanied by measurements of density and ultrasonic wave speed. Resulting dynamic MOE was partly used as an indicator of timber quality. 相似文献