共查询到20条相似文献，搜索用时 15 毫秒
1.
Okumu Gordon Wanyama Kei Sawata Takuro Hirai Akio Koizumi Yoshihisa Sasaki 《Journal of Wood Science》2012,58(4):315-321
In this study, an experimental study was conducted on the nailed timber–plywood–timber joints extended from the standard wall–floor joints of wooden light frame constructions, where the bottom plates of shear walls are nailed to the floors consisting of joists and floor sheathings nailed to them. The principal conclusions are as follows: The allowable lateral resistance of the nailed timber–plywood–timber joints can roundly be estimated by neglecting the plywood panels if their densities are higher than those of the timber main-members and they are fastened effectively onto the timber main-members. The stiffness of the timber–plywood–timber joints is less than that of the control timber–timber joints, which is improved by increasing the number of nails used to fasten the plywood panels onto the timber main-members. The stiffness of the joints whose floor sheathings are glued onto the joists is equivalent to the control timber–timber joints. The timber–plywood–timber joints with appropriate specifications have greater energy capacity until the failure than that of the control timber–timber joints. This ensures their energy capacity, which is important in dynamic resistance, to be equivalent to the control timber–timber joints. 相似文献
2.
This article summarizes an experimental and numerical study on seismic behavior of wood-framed shear walls with an opening.
The objectives of this study were to compare the results of static and pseudodynamic tests of plywood-sheathed shear walls
with numerical simulation by the Finite Element (FE) model and to validate a finite element code EFICOBOIS for such an application.
This software is based on a macroelement approach to limit the number of degrees of freedom for the whole system. Nonlinear
laws for connections such as nails and hold-down connections, among others, are applied through macroelements that link plate
elements to beam elements. Numerical results obtained for the various loading conditions showed good agreement with the experiments.
Both static and dynamic computations are presented here.
Received: February 15, 2002 / Accepted: April 25, 2002
Correspondence to:M. Yasumura 相似文献
3.
Jung-Kwon Oh Jung-Pyo Hong Chul-Ki Kim Sung-Jun Pang Sang-Joon Lee Jun-Jae Lee 《Journal of Wood Science》2017,63(1):45-55
A cross-laminated timber (CLT) wall plays the role of resisting shear stress induced by lateral forces as well as vertical load. Due to the press size, CLT panels have a limitation in size. To minimize the initial investment, some glulam manufactures wanted to make a shear wall element with small-size CLT panels and panel-to-panel connections and wanted to know whether the shear wall would have equivalent shear performance with the wall made of a single CLT panel. In this study, this was investigated by experiments and kinematic model analysis. Two shear walls made of small CLT panels were tested. The model showed a good agreement with test results in the envelope curve. Even though the shear walls were made of small panels, the global peak load did not decrease significantly compared with the wall made of a single CLT panel, but the global displacement showed a large increase. From this analysis, it was concluded that the shear wall can be designed with small CLT panels, but displacement should be designed carefully. 相似文献
4.
Kei Sawata Masahiko Toda Satoru Kanetaka Yoshihisa Sasaki Takuro Hirai 《Journal of Wood Science》2011,57(6):536-541
When it is necessary to repair conventional Japanese wooden houses, the decayed lower parts of columns should be replaced
with new wood material. The bending resistance of columns repaired by four methods and the shear resistance of opening frames
with those repaired columns were investigated in this study. Bending tests of the repaired columns showed differences in initial
bending stiffness and maximum bending moment related to the repair methods and loading direction. Racking tests were conducted
on door opening frames with conventional door head members or upper partial walls sheathed with 12-mmthick plywood. The conventional
frame specimens broke at door head-column joints with no obvious bending deformation of the columns, resulting in little difference
in load-shear deformation curves among the repair methods. The columns of plywood-sheathed specimens, on the other hand, clearly
were bent after the nails at the plywood-to-wood frame joints started to pull off. The load-shear deformation curves of the
plywood-sheathed specimens did not vary regardless of the repair methods when shear deformations were small but were affected
by repair methods as shear deformation increased. 相似文献
5.
6.
Minghao Li Frank Lam Ricardo O. Foschi Shiro Nakajima Takafumi Nakagawa 《Journal of Wood Science》2012,58(1):20-30
This paper presents a structural model called “PB3D” to perform nonlinear time history analyses of post and beam timber buildings
under seismic loads. The model treats the three-dimensional structure as an assembly of roof/floor diaphragms and wall subsystems.
The roof/floor diaphragms are modeled by beam elements and diagonal brace elements in order to take into account the in-plane
stiffness. The wall system consists of vertical beam elements, for wall posts, as well as nonlinear shear springs to consider
the contribution of diagonal wall bracing members or sheathing panels. The hysteretic characteristics of the shear springs
are represented by a simplified, mechanics-based model named a “pseudo-nail”. Standard finite element procedure is used to
construct the system’s equation of motion, which is solved by Newmark’s integration. The model was verified against shake
test results of a three-story post and beam building subjected to strong ground motions scaled to the 1995 Kobe earthquake.
Model predictions agreed very well with the test results in terms of base shear forces and inter-story drift responses. This
model provides a robust and efficient tool to study the seismic behavior of post and beam timber buildings. 相似文献
7.
8.
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
9.
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
10.
11.
Wood-based panels are subjected to cyclic panel shear load caused by wind and seismic forces in such an application as the sheathing of bearing walls. The fatigue behavior of structural plywood under panel shear load with two different loading frequencies was examined. Pulsating panel shear load with a triangular waveform and loading frequency of 0.5 or 5 Hz was applied to the plywood specimens. Stress−strain hysteresis loops were measured throughout the fatigue tests. Fatigue life was highly dependent on loading frequency at more than 0.5 stress level. The deterioration of mechanical property and damage accumulation in plywood specimen was observed to be slower at higher loading frequency at more than 0.5 stress level. Analyses based on energy loss suggest that panel shear load with higher loading frequency causes less damage to the plywood specimen during one loading cycle at higher stress level, and that the fatigue damage accumulation causing failure might be dependent on stress level although it seems to be unaffected by loading frequency. Based on these results, a new fatigue failure model for plywood specimen was qualitatively developed by combining Weibull’s weakest link model and Daniels’ fiber bundle model. 相似文献
12.
介绍轻型木结构楼、屋面板冲击荷载性能试验的条件、装置和方法,根据规范要求研制加载装置,并进行木结构用意杨结构胶合板的冲击荷载性能试验研究,旨在为国产速生林用于轻型木结构的研究提供一些试验数据。试验结果表明：与国外结构胶合板具有相同厚度的轻型木结构用意杨屋面板和楼面板,其冲击荷载受弯性能均优于我国木结构工程施工质量验收规范标准要求。 相似文献
13.
国产轻型木结构用落叶松胶合板覆板生产技术与性能评价 总被引：1，自引：0，他引：1
介绍了我国常规工艺生产的落叶松结构胶合板产品的各项物理、力学和结构性能,研究开发了轻型木结构用落叶松胶合板覆板的生产技术.通过采用厚单板组坯工艺,在工业化条件下生产了落叶松墙面板产品,并对其外观质量、规格尺寸、物理力学及结构性能进行了全面检验和分析比较.结果表明,国产落叶松结构胶合板墙面板的各项性能均达到和超过北美及相关标准要求,可以用作轻型木结构房屋覆板. 相似文献
14.
1 INTRODUCTIONConservation of natural forests is a key issue in China’ssustainable rural development. One of the problems inrural China is the use of large quantities of wood andred bricks in house construction. This causesdestruction of forests, and the consequent watershortage and soil erosion problems.With the increase in living standards in rural areas,demand for housing is growing, and so is the demandfor high quality and attractive hotels for tourists.Moreover, many schools in Chi… 相似文献
15.
竹胶合梁制造及在建筑中的应用 总被引：12，自引：0，他引：12
在国际竹藤组织和中国林业科学研究院的技术支持下,第一所用竹材制作的云南省屏边小学校舍于2004年建成.它的校舍屋架,屋顶板和内外墙板均为竹集成材和竹胶合板制成.这使竹材从天然传统建筑材料向现代工程建筑材料转变,扩大了竹材在建筑领域的应用范围,对中国竹产业和建筑材料产业的发展将有积极深远影响. 相似文献
16.
17.
18.
In the previous report of this ongoing study, results of an extensive field survey were collated and a theoretical model was
proposed to predict the mechanical behavior of timber shear walls of traditional design in Taiwan. The initial objective of
the present report was to propose a simplified calculation method for estimating the initial stiffness and yield strength
of traditional timber shear walls. Based on the results of the field survey, a total of 15 full-scale specimens were tested
to verify the theoretical model and simplified calculation proposed previously. Good agreement was found from comparison of
analytical and experimental results. The results of this study show that the friction behavior between board units and beams
plays the major role in resisting the lateral force applied on the timber shear wall, followed by the resistance supplied
by embedment. The resistance provided by bamboo nails is minor due to the small section. Another trend found was that for
set dimensions of a timber shear wall, the board width can be increased to obtain higher stiffness and strength of the shear
wall. 相似文献
19.
Wood-based panels such as plywood, oriented strand board, particleboard, and medium-density fiberboard are used for roof, wall and floor sheathing materials in residential construction. However, the service life of these panels is still unknown due to the lack of long-term durability data. In this paper, test results from six different indoor exposure experiments were integrated to investigate the long-term durability of wood-based panels. The indoor exposure tests lasted for a maximum of 10 years, providing the panels with the changes in moisture content that ranged between 5 and 18%. The reduction in mechanical properties was determined to be in the range of 0–16% for the bending strength, 3–22% for the modulus of elasticity, 11–31% for the internal bond strength and 0–8% for the nail-head pull-through strength. No reduction was recognized for the lateral nail resistance. Furthermore, the concept of deterioration intensity (DI) based on the moisture content history was introduced to predict the long-term durability of the panels, and various calculation methods for DI were discussed so as to increase the correlativity of this property with the reduction in a mechanical property. 相似文献
20.
In this study we tried to develop an analysis program that can simulate the collapsing process of timber-frame structures under dynamic loading by adopting the extended distinct element method (EDEM). Using the EDEM, it is possible to trace the movement of any parts that were separated from unity after the failure of connecting elements, a property that fits our purpose well. As a preliminary study, simple two-story frame structures were modeled and examined by our program. Each model is an assembly of frame members composed of the EDEM elements. The spring elements of the joints have less rigidity than those of the frame members. Several models were analyzed under dynamic loading. The models varied in the configuration of bracing shear walls. Experiments with a one-ninth model were carried out under similar conditions, and the results were compared with the results from numerical simulations. Simulated results showed various collapsing processes corresponding to the arrangement of the bracing shear wall, and the simulated aspects gave good agreement with the results of the experiments under similar conditions.Part of this paper was presented at the 50th Annual Meeting of the Japan Wood Research Society, Kyoto, April 2000 相似文献