• Journal of Korean Society of Steel Construction
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• v.24 no.2
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• pp.189-197
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• 2012

The cold-formed steel stud, which has been used as a load-bearing member of wall panels for steel houses, poses a significant problem in insulation due to heat bridging of the web. Therefore, some additional thermal insulating materials are required. In order to solve this problem, the cold-formed steel thermal stud with slits in the web was developed. However, estimating the structural strength of thermal studs is very difficult because of the arrangement of perforations. In this paper, an analytical and experimental research on thermal studs is described. Three types of studs with different length, pitch and arrangement of slits were tested to failure. A simple design approach was proposed based on the test results. The proposed method adopted the direct strength method, based on the elastic local and distortional buckling stress of plain studs with equivalent thickness in the web instead of thermal studs. The predictions using the proposed method were compared with test results for verification and the adequacy of the proposed method was confirmed.

• Steel and Composite Structures
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• v.16 no.6
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• pp.657-679
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• 2014

This paper describes a series of compression tests performed on cold-formed steel channel sections with perforations in the web (thermal studs) fabricated from a galvanized steel plate whose thickness ranged from 1.0 mm to 1.6 mm and nominal yield stress was 295 MPa. The structural behavior and performance of thermal studs undergoing local, distortional, or flexural-torsional buckling were investigated experimentally and analytically. The compression tests indicate that the slits in the web had significant negative effects on the buckling and ultimate strength of thin-walled channel section columns. The compressive strength of perforated thermal studs was estimated using equivalent solid channel sections of reduced thickness instead of the studs. The direct strength method, a newly developed and adopted alternative to the effective width method for designing cold-formed steel sections in the AISI Standard S100 (2004) and AS/NZS 4600 (Standard Australia 2005), was calibrated to the test results for its application to cold-formed channel sections with slits in the web. The results verify that the DSM can predict the ultimate strength of channel section columns with slits in the web by substituting equivalent solid sections of reduced thickness for them.

• Journal of the Korean Solar Energy Society
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• v.34 no.3
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• pp.107-114
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• 2014

Modular systems are widely used in various building types including housing, dormitory, and barracks. Steel studs have many advantages over other materials as construction components of modular buildings in terms of seismic performance, durability and maintenance. However, steel stud modular systems also have weakness in condensation resistance due to high thermal conductivity of steel. The purpose of this study is to investigate the condensation resistance of steel stud wall corner details in modular buildings by thermal simulation. The condensation resistance was evaluated by temperature difference ratio according to ISO 13788. The result showed that there was little difference between the alternatives of adding cavity and insulation. Separation of interstitial steel studs showed outstanding effect on the improvement of temperature difference ratio.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.05a
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• pp.527-528
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• 2010

Previous experimental results performed by many researchers for a couple of decades in South Korea have shown that an absorbing sheet inserted in a conventional floating slab system for thermal insulation or vibration absorption may amplify the vibration of the slab system at specific frequency ranges depending on the material properties of the sheet. The amplified vibration, consequently, results in the heavy weight floor impact noise exceeding the sound level limit for an apartment house, 50dB. In this study, the amplification mechanism is examined through numerical analysis and a new slab system is proposed to reduce the amplification and control the noise. The new slab system consists of studs connecting the base slab and upper concrete finishing yielding the dramatically increased stiffness of the slab. The numerical simulation is performed to investigate the effect of the slab system with studs on the vibration and noise control. The results show that the performance of the slab is sensitive to the number and location of studs, and the heavy weight floor impact noise can be reduced up to 6-7dB compared to the conventional slab system at the optimal stud location.

• Steel and Composite Structures
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• v.43 no.4
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• pp.483-500
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• 2022

Cold-formed steel wall panels sheathed with gypsum plasterboard have shown superior thermal and structural performance in fire. Recent damage caused by fire events in Australia has increased the need for accurate fire resistance ratings of wall systems used in low- and mid-rise construction. Past fire research has mostly focused on light gauge steel framed (LSF) walls under uniform axial compression and LSF floors under pure bending. However, in reality, LSF wall studs may be subject to both compression and bending actions due to eccentric loading at the wall to-roof or wall-to-floor connections. In order to investigate the fire resistance of LSF walls under the effects of these loading eccentricities, four full-scale standard fire tests were conducted on 3 m × 3 m LSF wall specimens lined with two 16 mm gypsum plasterboards under different combinations of axial compression and lateral load ratios. The findings show that the loading eccentricity can adversely affect the fire resistance level of the LSF wall depending on the magnitude of the eccentricity, the resultant compressive stresses in the hot and cold flanges of the wall studs caused by combined loading and the temperatures of the hot and cold flanges of the studs. Structural fire designers should consider the effects of loading eccentricity in the design of LSF walls to eliminate their potential failures in fire.

• Journal of the Korean Wood Science and Technology
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• v.45 no.1
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• pp.1-11
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• 2017

A lot of the energy are consumed on heating and cooling in buildings. The buildings need to minimize the heating and cooling loads for $CO_2$ emissions and energy consumption reduction. In recently, also demand of detached houses were increase while the residential culture was changed. The structure of the domestic detached houses can be divided into masonry, concrete, wood frame houses. Therefore, in this study, the heating and cooling load and energy demand were analyzed on the equal area detached house consisting of three structural methods (Masonry, Concrete, Wood frame). Layer of wall, roof, and floor were composited by structure. Thermal transmittance (U-value) of each layer was using the PHPP calculation for considering stud, such as the wood frame wall. In addition, the case of without considering for studs in wood frame wall (Non-studs) was analyzed in order to compare the difference between studs or not. Analysis was performed using self-developed heating and cooling load calculation program (CHLC) based excel and ECO2. The results of cooling and heating load and energy demand showed the highest values in the wood frame structure, and the concrete structure were confirmed to maintain a high value secondly. Two structure were determined to be disadvantageous on the energy consumption. Consequently, the masonry structure have an advantage over the other structure under the identical conditions. It was determined that if the except for thermal bridges due to the studs in the wood frame structure, it can be reduced the energy consumption.

• 한국태양에너지학회:학술대회논문집
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• 2009.11a
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• pp.236-240
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• 2009

Dry wall using steel stud has the advantage of possibility to install various building, so it used to many buildings inside and outside of the country very rapidly. Though Light gauge steel framed housing offers many advantages to the consumer and the builder, the use of steel studs in wall system cause thermal problems such as thermal performance and pattern staing on walls. The present study has been conducted to observe effect of stud by the shape, and two kind of stud is made for this test to compare thermal performance. The test was conducted by setting those stud on the chamber and heating them. As the results of test and photograping by using TVS, there was temperature gap of each stud, and surface temperature of each section was appeared differently due to shape of stud delaying thermal bridge.

• Journal of Korean Society of Steel Construction
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• v.16 no.5 s.72
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• pp.609-619
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• 2004

An investigation was conducted on the activities around Europe in order to solve the problem of the thermal bridging of steel studs, which had caused a significant disadvantage. This study included the following: diminishing the contact area between the studs and the sheathing, lengthening the heat transfer route, replacing the steel web with a less conductive material, and placing foam insulation in locations where the thermal shorts are most critical. Although energy efficiency is usually the focus of such foreign cases because their stud application is mostly limited to low-rise residential buildings, both structural and thermal performance are taken into consideration in this study because these target middle-story buildings. A hybrid stud composed of steel and polymer was also developed. This hybrid stud, which is 150 SL in size, is made of a galvanized steel sheet (SGC58) and a glass fiber reinforced polymer (GFRP) withepoxy bonding. A total of 32 specimens were manufactured. Its parameters comprise two types of connection detail,s: the thickness of steel (1.0mm and 1.2mm) and of the GFRP (4mm-4ply and 6mm-6ply), and the ratio of the length to the depth (L/D = 3, 6, 9, 12). Steel stud specimens with the same conditions were compared to the hybrid stud. The test revealed that in the case of the steel specimen with a thickness of 1.0mm, the maximum load of hybrid studs increased an average of 1.62 times comparedto that of the steel stud. In the case of the steel specimen with a thickness of 1.2mm, on the other hand, the average increase was 1.46times. All specimens showed full composite action until the collapse.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.7
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• pp.651-657
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• 2010

Previous experimental results performed by many researchers for a couple of decades in South Korea have shown that an absorbing sheet inserted in a conventional floating slab system for thermal insulation or vibration absorption may amplify the vibration of the slab system at specific frequency ranges depending on the material properties of the sheet. The amplified vibration, consequently, results in the heavy weight floor impact noise exceeding the sound level limit for an apartment house, 50 dB. In this study, the amplification mechanism is examined through numerical analysis and a new slab system is proposed to reduce the amplification and control the noise. The new slab system consists of studs connecting the base slab and upper concrete finishing yielding the dramatically increased stiffness of the slab. The numerical simulation is performed to investigate the effect of the slab system with studs on the vibration and noise control. The results show that the performance of the slab is sensitive to the number and location of studs, and the heavy weight floor impact noise can be reduced up to 6~7 dB compared to the conventional slab system at the optimal stud location.

• Journal of Korean Society of Steel Construction
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• v.18 no.5
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• pp.543-551
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• 2006

Cold-formed steel studs that are being used as load-bearing members of wall panels for steel houses have a problem with their insulation due to the heat bridging of their web. Some additional thermal insulating materials should be used. To solve this problem, the new-concept hybrid stud, which consists of a galvanized steel sheet (t = 1.0 m - 12.0 m) and a GFRP panel (t = 4.0-6.0 mm), has recently been developed. An investigation on the structural behavior and the strength capacity of this new hybrid stud has been conducted so that it can be used in load-bearing wall panels of residential buildings. This paper describes the axial compression-torsion test results of the hybrid studs under both axial compression and torsion using ATTM. The main factors of the test were the stud length, the magnitude of the initial compressive force, and the loading method of the monotonic or cyclic loading. The torsion was applied increasingly while the initial compression was kept constant to the failure of the hybrid section. The advanced analysis results obtained form the finite element procedure that considered the material properties of the high-strength galvanized steel and the GFRP were compared with the test results for verification.