scholarly journals Effect of Loading Speed on the Mechanical Properties of Nail Joints

Author(s):  
Shervin Shameli Derakshan ◽  
Lina Zhou ◽  
Chun Ni

Wood shear walls are the main lateral load resisting systems in light wood frame buildings to resist the wind and seismic loads. Sheathing to lumber nail connections are regarded as the key components that control the resistance and failure modes of wood shear walls. Considerable experimental tests have been conducted on performance of nail joints or wood shear walls under both static and reversed cyclic loads. However, these tests were usually conducted under different loading speed causing specimen failure in 1 min to an hour. It is unclear how the loading speed will affect the test results of nail joints or wood shear walls. Research on these topics is limited. This paper aims to evaluate the effect of loading speed on the mechanical characteristics of nail joints. 72 specimens have been tested under various loading speeds, ranging from 0.05 mm/s to 0.5 mm/s for monotonic tests and 1.5 mm/s to 15 mm/s for reversed cyclic tests. The range of loading speed was selected based on the total estimated loading time that both monotonic and reversed cyclic tests fail within around 1 min to 10 min. Two groups of nail joints, comprising two common nail sizes and two sheathing thicknesses, were assessed under both monotonic and reversed cyclic loads. From the test results, the effect of loading speed on the mechanical properties of nail joints was determined.

2012 ◽  
Vol 517 ◽  
pp. 135-140 ◽  
Author(s):  
Zhi Li ◽  
Yan Xiao ◽  
Bo Shan ◽  
Lei Li ◽  
Rui Wang

This paper reports the first step of a study to evaluate the lateral resistance capacity of Round bamboo shear walls and its mechanical properties under Monotonic and cyclic loading conditions. The bamboo shear walls are built with round bamboo as its stub and with ply-bamboo sheet as its sheathing. Load-displacement curves of six round bamboo shear walls, with three different connection types, were obtained in this experiment, and the test results showed that the lateral resistance capacity of round bamboo shear walls can exceed 4.0kN/m, satisfying the projects requirement. A combination of nail and panel failures were observed in the test.


2017 ◽  
Vol 2017 ◽  
pp. 1-20
Author(s):  
Ulf Arne Girhammar ◽  
Bo Källsner

The authors present an experimental and analytical study of slotted-in connections for joining walls in the Masonite flexible building (MFB) system. These connections are used for splicing wall elements and for tying down uplifting forces and resisting horizontal shear forces in stabilizing walls. The connection plates are inserted in a perimeter slot in the PlyBoard™ panel (a composite laminated wood panel) and fixed mechanically with screw fasteners. The load-bearing capacity of the slotted-in connection is determined experimentally and derived analytically for different failure modes. The test results show ductile postpeak load-slip characteristics, indicating that a plastic design method can be applied to calculate the horizontal load-bearing capacity of this type of shear walls.


1991 ◽  
Vol 81 (5) ◽  
pp. 2111-2126
Author(s):  
R. Shepherd ◽  
E. O. Delos-Santos

Abstract Extensive damage was experienced by wood-frame buildings during the Loma Prieta earthquake. A significant contributory factor was the collapse of cripple walls. This prompted the examination of the behavior of a group of full-scale retrofitted cripple walls subjected to in-plane cyclic loads. The results of investigating seven cripple walls, each 2 ft (0.61 m) high and 16 ft (5 m) long, are presented. Two are control panels, without retrofits. Two are strengthened with 1 by 6 inch (25.4 by 153 mm) braces. Two are retrofitted with 0.5 inch (12.7 mm) plywood and one with a steel strap tie. Stiffness, strength, and damping characteristics are summarized, together with cost aspects. It is shown that relatively cheap and straightforward modifications can substantially eliminate the vulnerability of many existing cripple walls to earthquake shaking.


2011 ◽  
Vol 413 ◽  
pp. 529-534
Author(s):  
Hui Feng Yang ◽  
Wei Qing Liu ◽  
Wei Dong Lu ◽  
Shu Ai Yan

In this paper, a total of five structural insulated panel shear walls (SIPSW), in which with plywood facing and polystyrene foam board core, were tested under low cyclic horizontal loading. For the test specimens, different wall depth-width ratio and the opening sizes have been considered. The failure modes, failure mechanics, bearing capacity, lateral stiffness and ductility are discussed in detail. The test results showed that the hysteretic curve of SIPSW shows a reversed S-shape. Also the depth-to-width ratio and the opening dimensions of the shear walls have significant effects on load bearing capacity, ductility and elastic stiffness. What’s more, the performance of the SIPSW specimens was controlled by the fastener slip behavior of the SIP-to-spline connection, especially along the bottom spline. Finally, it is indicated that SIPSW have a good satisfaction upon seismic performance when used to timber structures.


2012 ◽  
Vol 517 ◽  
pp. 164-170 ◽  
Author(s):  
Juan Francisco Correal ◽  
Sebastian Varela

Wood frame buildings have shown good performance on past earthquakes mainly because the lateral system of those buildings was able to dissipate energy without significant loss of lateral capacity. Typically, the lateral load resisting system is provided by wood shear walls, which consist of a wood frame sheathed with wood or wood-based composites, such as Plywood or OSB panels. Taking into account the increasing forest demand for wood, there is a global need to find alternative energy-efficient, renewable and eco-friendly construction materials. Giant bamboo like Guadua Angustifolia kunt emerges as an interesting construction material, since it has a fast growing rate (3 to 4 years), high strength to weight ratio and high carbon (CO2) capture capabilities. Results of a past study conducted at the Universidad de los Andes in Bogotá-Colombia reported that Glued Laminated Guadua Bamboo (GLG) has mechanical properties comparable to those of the best structural timbers in Colombia. Potential applications of GLG include not only laminated beams and columns, but also structural panels to be used as a sheathing material for wood frame shear walls. A comprehensive experimental study has been performed on GLG sheathed shear walls in order to find an alternative sheathing material for wood frame buildings as well as to explore their possible application for residential and/or commercial construction in Colombia. A series of tests were conducted on full-size shear wall specimens in order to study the influence of the wall aspect ratio and the edge nail spacing on the shear wall performance. Based on cyclic tests on shear walls, it was found that the stiffness and maximum load carrying capacity of the wall increases as edge nail spacing decreases. In contrast, the displacement ductility capacity decreases, since the rotation of the panels is restricted when the edge nail spacing is reduced. Experimental results also revealed that stiffness, maximum load capacity, and ductility of the GLG sheathed shear walls are not affected by the aspect ratio of the wall. The final stage of the present study included dynamic shake-table tests on full-size one and two-story housing units using GLG sheathed shear walls. Results showed that the units had similar performance characteristics to those of OSB and Plywood sheathed shear walls, and it was concluded that wood-GLG combination could be a viable construction alternative from a structural point of view.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jing Di ◽  
Hongliang Zuo

PurposeThe sheathing panels of traditional light wood frame shear walls mainly use oriented strand board (OSB) panels, and the damage of the traditional walls is mainly caused by the tear failure at the bottom corner of the OSB panel. In order to improve the lateral performance of the traditional light wood frame shear wall, a new type of end narrow panels reinforced light wood frame shear wall is proposed.Design/methodology/approachThe monotonic loading tests and finite element analysis of nine groups of walls, with different types of end narrow panel, types of fasteners used on the end narrow panels and the end narrow panels edge fastener spacing, are carried out. The effects of different characters on lateral performance of light wood frame shear walls are reported and discussed.FindingsThe failure modes of the wall reinforced by parallel strand bamboo narrow panels with 150 mm edge nails spacing are similar to the traditional wall. Conversely, the failure modes of other groups of walls reinforced by end narrow panels are the tears of the bottom narrow panel or the bottom beam. The end narrow panel reinforced light wood frame shear wall can make full use of the material property of sheathing panels. Compared with the lateral performance of traditional walls, the new-type end narrow panels reinforced walls have better lateral performance.Originality/valueA new type of end narrow panels reinforced light wood frame shear wall is proposed, which can enhance the lateral performance of the traditional light wood frame shear wall. The new-type walls have advantages of convenient operation, manufacture cost saving and important value of engineering application.


2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Yun-liang Tan ◽  
Wei-yao Guo ◽  
Tong-bin Zhao ◽  
Feng-hai Yu ◽  
Bin Huang ◽  
...  

Many case studies have revealed that rock bursts generally occur in the high stress concentration area where layer-crack structures often exist, especially for brittle coal or rock masses. Understanding the mechanical properties of layer-crack rock models is beneficial for rational design and stability analysis of rock engineering project and rock burst prevention. This study experimentally investigated the influence of fissure number on the mechanical properties of layer-crack rock models through uniaxial compression tests. The digital speckle correlation method (DSCM) and acoustic emission (AE) techniques were applied to record and analyze the information of deformation and failure processes. Test results show the following: the bearing capacity of layer-crack specimen decreases compared with intact specimen, but their failure modes are similar, which are the splitting failure accompanied with local shear failure; the nonuniform deformation phenomenon begins to appear at the elastic deformation stage for layer-crack specimens; the AE behavior of intact specimens consists of three stages, that is, active stage, quiet stage, and major active stage, but for layer-crack specimens, it is characteristic by three peaks without quiet stage. In addition, as the fissure number of layer-crack specimens increases, the bearing capacity of specimens decreases, the appearing time of nonuniform deformation phenomenon in the specimen surface decreases, the AE events are denser and denser in each peak stage, and the risk of dynamic instability of layer-crack structure increases. At last, the failure mechanism of layer-crack structure and the related mitigation advices were discussed based on the test results. In general, the novelty is that this paper focuses on the failure mechanism of layer-crack structure directly.


2012 ◽  
Vol 602-604 ◽  
pp. 1566-1569
Author(s):  
Yun Cheul Choi ◽  
Hyun Ki Choi ◽  
Chang Sik Choi

Generally because of the economic advantage and stable behavior in seismic loading, shearwalls combined with coupling slabs are widely used in high-rise apartment buildings. When analyzing such structures for lateral loads, however, the question of the actual stiffness and strength of the coupling slabs arises. For more accurate analysis approach, an experimental investigation was conducted with half-scale representations of the reinforced concrete shearwalls with the opening and coupled with slabs were subjected to cyclic loads. The test results of opening installed specimen, severe decrease of strength was observed. The decrease of strength of the shear walls by installation of openings shows a great deal of difference compared to previous researches. This is because flexural capacity of the slabs is working as coupling elements for the shear walls. The critical section of coupling slabs that works as coupling elements for shear walls was a little different from the results of previous researches.


2010 ◽  
Vol 163-167 ◽  
pp. 1569-1573 ◽  
Author(s):  
Shi Xiang Huang ◽  
Xin Yu Zhao

The cyclic tests of three one-storey spatial RC frame-shear wall structures with slabs were conducted to investigate the failure modes and the base shear-floor displacement hysteretic responses of the model structures. Then three dimensional numerical simulations were performed using the finite element program ABAQUS/Standard and ABAQUS/Explicit. The test results are detailed in this paper and compared to those of the numerical simulations. It is shown that: (a) plastic hinges initiated at the bottom of the shear wall and followed by forming near the upper ends of columns, resulting in wall-column hinges side-sway failure mechanism; (b) to a certain extent, the horizontal force bearing capacity of the structure increases with the increasing of the vertical load; (c) it is verified that the pushover results of both ABAQUS/Standard and ABAQUS/Explicit solutions agree well with the test results in the case that the parameters are reasonably chosen.


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