• Journal of the Korean Wood Science and Technology
• /
• v.30 no.3
• /
• pp.97-103
• /
• 2002

This study was carried out to obtain basic information on racking resistance of shear walls and the factors affecting racking resistance of shear walls. Shear walls constructed by larch lumber nominal 50 mm × 100 mm framing and various sheathing materials were tested by applying monotonic and cyclic load functions. Shear walls with various stud spacing such as 305 mm, 406 mm, and 610 mm were tested under both of monotonic and cyclic loads and shear walls with various aspect (height-width) ratios were tested under cyclic load functions. The effect of hold-down connectors in shear walls was also tested under cyclic load functions. Racking resistance of shear walls has very close linear relation with stud spacing and width of shear walls. The ultimate racking strength of shear walls was reached at around or before the displacement of 20 mm. It was proposed in this study that the minimum racking strength and minimum width for shear wall be 500 kgf and 900 mm, respectively. Load-displacement curves obtained by racking tests under monotonic load functions can be represented by three straight line segments. Under cyclic load functions, envelope curves can be divided into three sections that can be represented by straight lines and the third section showed almost constant or decreasing slope.

• Steel and Composite Structures
• /
• v.30 no.5
• /
• pp.457-469
• /
• 2019

Steel pallet racking industry has globally used from the industrial revolution and has deeply evolved from hot-rolled profile into cold-formed profile to raise the optimization in engineering field. Nowadays, some studies regarding cold-formed steel profile have been performed, but fewer studies in terms of cold-formed pallet racking specifically in connection due to the semi-rigid behavior by lug-hooked into the upright have been conducted. The objective of this study is to review the related literature on steel storage racking connection behavior.

• Journal of the Korean Wood Science and Technology
• /
• v.30 no.4
• /
• pp.96-105
• /
• 2002

Shear wall is the most important component resisting lateral loads imposed to a building by wind or earthquake. In shear walls, lateral load applied to framing is transmitted to sheathing panel through nailed joints between sheathing and framing so that the load is resisted by in-plane shear strength of sheathing. Therefore, nailed joints are the most basic and important component in the viewpoint of stiffness and strength of shear walls. In this study, stiffness and strength of single nailed joint were measured by single shear tests of nailed joints and used as input for theoretical models developed to estimate racking behavior of shear walls. And shear walls were tested to check the accuracy of theoretical models estimating racking resistance of shear walls. Stiffness of nailed joint was affected by grain direction of stud but direction of sheathing panel had little effect. Behavior of nailed joint and shear walls under lateral loads could be represented by three lines. Theoretical model II was more accurate than theoretical model I in estimating racking behavior of shear wall under loads.

• Structural Engineering and Mechanics
• /
• v.20 no.1
• /
• pp.45-67
• /
• 2005

This paper presents a new approach to predict the racking load-displacement response of plasterboard clad walls found in Australian light-framed residential structures under monotonic racking load. The method is based on a closed-form mathematical model, described herein as the 'Modularised' Closed-Form Mathematical model or MCFM model. The model considers the non-linear behaviour of the connections between the plasterboard cladding and frame. Furthermore, the model is flexible as it enables incorporation of different nailing patterns for the cladding. Another feature of this model is that the shape of stud deformation is not assumed to be a specific function, but it is computed based on the strain energy approach to take account of the actual load deformation characteristics of particular walls. Verification of the model against the results obtained from a detailed Finite Element (FE) model is also reported. Very good agreement between the closed form solution and that of the FE model was achieved.

• Journal of the Korean Society for Advanced Composite Structures
• /
• v.3 no.2
• /
• pp.19-27
• /
• 2012

Structural insulated panels, which are structurally performed panels consisting of a plastic insulation bonded between two structural panel facings are one of emerging products with a viewpoint of its energy and construction efficiencies. These components are applicable to fabricated wood structures. By now, there are few technical documents regulated structural performance and engineering criteria in domestic market. This study was conducted to suggest fundamental reports such as racking resistance, axial capacity, transverse load capacity, and lintel load capacity for SIPs. Test results showed that maximum load was 44.3kN, allowable load was 14.7kN for racking resistance, and that maximum load was 137.6kN, allowable load was 37.4kN/m for axial compression capacity. For transverse load capacity, test results showed $10.3kN/m^2$ of maximum load, $3.4kN/m^2$ of allowable load. For lintel load capacity for SIPs dependent to lengths, allowable loads were 20.4kN for 600mm long lintel, 23.9kN for 1,200mm long lintel, 19.3kN for 1,800mm long lintel, and 2,400mm long lintel had 14.1kN of allowable load. In the near future, when the allowable load for wall application is established, SIPs is considered to substitute the existent post-and-lintel construction to bearing wall structure.

• Steel and Composite Structures
• /
• v.19 no.6
• /
• pp.1403-1419
• /
• 2015

When precast concrete infill panels are connected to steel frames at discrete locations, interaction at the structural interface is neither complete nor absent. The contribution of precast concrete infill panels to the lateral stiffness and strength of steel frames can be significant depending on the quality, quantity and location of the discrete interface connections. This paper presents preliminary experimental and finite element results of an investigation into the composite behaviour of a square steel frame with a precast concrete infill panel subject to lateral loading. The panel is connected at the corners to the ends of the top and bottom beams. The Frame-to-Panel-Connection, FPC4 between steel beam and concrete panel consists of two parts. A T-section with five achor bars welded to the top of the flange is cast in at the panel corner at a forty five degree angle. The triangularly shaped web of the T-section is reinforced against local buckling with a stiffener plate. The second part consists of a triangular gusset plate which is welded to the beam flange. Two bolts acting in shear connect the gusset plate to the web of the T-section. This way the connection can act in tension or compression. Experimental pull-out tests on individual connections allowed their load deflection characteristics to be established. A full scale experiment was performed on a one-storey one-bay 3 by 3 m infilled frame structure which was horizontally loaded at the top. With the characteristics of the frame-to-panel connections obtained from the experiments on individual connections, finite element analyses were performed on the infilled frame structures taking geometric and material non-linear behaviour of the structural components into account. The finite element model yields reasonably accurate results. This allows the model to be used for further parametric studies.

• Korean Journal of Agricultural Science
• /
• v.37 no.2
• /
• pp.271-276
• /
• 2010

In this study, the light-frame wood shear walls according to the sheathing materials was carried out to investigate the shear load performance. Most common sheathing materials are the structural OSB and gypsum board used to consist wall of wood-frame house. Seven different type of specimens are composed of several sheathing materials and shear test was taken to evaluate shear performance by KS F 2154. As a result, shear walls(G12.5/G12.5 and G12.5/OSB) show that maximum shear strength and shear rigidity modulus are 7316N/mm${\cdot}$118.25 N/mm and 11129 N/mm${\cdot}$184.66 N/mm respectively. The shear wall using gypsum board 15mm improve maximum shear strength and shear rigidity modulus about 30%. The shear wall using 15mm gypsum board showed intermediate value in one side specimens. Different types of shear walls could be compared with the shear load performance. Also, nailed joint failure aspects are different to sheathing material and installing method.

• Smart Structures and Systems
• /
• v.26 no.1
• /
• pp.103-115
• /
• 2020

The cold-formed steel storage racks are extensively employed in various industries applications such as storing products in reliable places and storehouses before distribution to the market. Racking systems lose their stability under lateral loads, such as seismic actions due to the slenderness of elements and low ductility. This justifies a need for more investigation on methods to improve their behavior and increase their capacity to survive medium to severe loads. A standardized connection could be obtained through investigation on the moment resistance, value of original rotational stiffness, ductility, and failure mode of the connection. A total of six monotonic tests were carried out to determine the behavior of the connection of straight 2.0 mm, and 2.6 mm thickness connects to 5 lug end connectors. Then, the obtained results are benched mark as the original data. Furthermore, an extreme learning machine (ELM) technique has been employed to verify and predict both moment and rotation results. Out of 4 connections, increase the ultimate moment resistance of connection by 13% and 18% for 2.0 mm and 2.6 mm upright connection, respectively.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1997.10a
• /
• pp.3-23
• /
• 1997

The growth in fast-track construction and repair has prompted major efforts to develop high-early-strength concrete mix compositions. Such mixtures rely on the use of relatively high cement contents and accelerator dosages to increase the rate of strength development. The measures, however, seem to compromise the long-term performance of concrete in applications such as full-depth patches as evidenced by occasional premature deterioration of such patches. The hypothesis successfully validated in this research was that traditional methods of increasing the early-age strength of concrete, involving the use of high cement and accelerator contents, increase the moisture and thermal movements of concrete. Restraint of such movements in actual field conditions, by external or internal restraining factors, generates tensile stresses which introduced microcracks and thus increase the permeability of concrete. This increase in permeability accelerates various processes of concrete deterioration, including freeze-thaw attack. Fiver reinforcement of concrete is an effective approach to the control of microcrack and crack development under tensile stresses. Fibers, however, have not been known of accelerating the process of strength gain in concrete. The recently developed specialty cellulose fibers, however, were found in this research to be highly effective in increasing the early-age strength of concrete. This provides a unique opportunity to increase the rate of strength gain in concrete without increasing moisture an thermal movements, which actually controlling the processes of microcracking and racking in concrete. Laboratory test results confirmed the desirable resistance of specialty cellulose fiber reinforced High-early-strength concrete to restrained shrinkage microcracking an cracking, and to different processes of deterioration under weathering effects.