• Structural Engineering and Mechanics
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• 제54권1호
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• pp.149-168
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• 2015

In the bolted connections, bolt placements are generally described and are generally made in the direction of design effects and in the perpendicular direction to design effects. In these both directions, the reliability of the distance of bolts to the edges of connection plate and the distance of bolts to each other is investigated for high strength steel connections built up with high strength bolts in this study. For this purpose, simple SL (bearing type shear connection) and SLP (bearing type shear connection for body-fit bolts) type steel connections with St 52 grade steel plates with 8 different thicknesses and with 8.8D grade high strength bolts (HV) were constituted and analyzed under H (Dead Loads+Live Loads+Snow Loads+Roof Loads) and HZ (H Loads+Wind Loads+Earthquake Loads) loadings. Geometric properties, material properties and design actions were taken as random variables. Monte Carlo Simulation method was used to compute failure risk and the first order second moment method was used to determine the reliability indexes of those different distances describing the placement of bolts. Results obtained from computations have been presented in graphics and in a Table. Then, they were compared with some values proposed by some structural codes. Finally, new equations were constituted for minimum and maximum values of distances describing bolt placement by regression analyses performed on those results.

• 한국강구조학회 논문집
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• 제24권5호
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• pp.605-612
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• 2012

표준공으로 고장력볼트를 체결한 인장부재는 구조내력은 증가하지만 시공성이나 경제성 측면에서 문제점을 야기시키게 된다. 본 연구에서는 인장부재의 고장력볼트 체결부를 표준공 및 과대공으로 하는 총 28개의 시험편을 제작하여 인장시험을 실시하였다. 시험결과로부터 얻어진 표준공 및 과대공 시험편의 인장하중을 순단면 및 연단거리에 의한 설계강도와 비교하여 연결부의 강도변화를 확인하였다. 과대공으로 제작된 시험편의 인장하중은 표준공으로 제작된 시험편의 인장하중보다 감소하였으나, 현행 설계기준의 설계강도를 상회하였으며 과대공으로 인하여 다소의 강도저하는 부득이하지만 안전성을 만족하였다.

• Journal of the Korean Wood Science and Technology
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• 제36권1호
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• pp.69-78
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• 2008

국내산 낙엽송 집성재 볼트, 드리프트 핀 접합부의 내력성능평가를 위해 인장형 전단강도시험을 실시하였다. 인장형 전단시편은 강판삽입형 볼트, 드리프트 핀 접합부 시편과 강판측재형 볼트접합부시편으로 제작하였다. 실험에 사용된 볼트와 드리프트 핀의 직경은 12, 16, 20 mm였다. 시편의 접합구멍은 끝면거리 5, 7 d로 제작하였고 인장하중은 섬유평행방향으로 가하였다. 끝면거리에 따른 접합부의 내력성능을 검토하고 Larsen의 항복추정식을 통해 항복하중을 실측항복하중과 비교하였다. 설계표준 시 끝면거리 7 d의 항복하중을 기준으로 5 d의 저감계수를 산출하였다. 본 연구의 결과는 다음과 같다. 1. 강판삽입형 접합부에서 드리프트 핀 접합부의 평균최대하중은 직경이 증가함에 따라 볼트 접합부보다 3~30% 정도 크게 나타났다. 볼트 접합부의 경우 강판측재형의 평균최대하중은 강판삽입형보다 1.54~2.07배 크게 나타났다. 동일 직경에서 끝면거리 7 d의 평균최대하중이 5 d보다 8~44% 정도 크게 나타났다. 2. 강판삽입형 접합부의 지압응력은 드리프트 핀 접합부가 볼트보다 1.16~1.41배 더 크게 나타났으며, 7 d가 5 d보다 1.37~1.86배 크게 나타났다. 또한 드리프트 핀 접합부의 세장비는 7.5 이하, 강판삽입형 볼트 접합부의 세장비는 6 이하에서 양호한 내력성능을 보였다. 3. 실측 항복하중과 Larsen이 제안한 항복하중 추정식에 의해 얻어진 항복하중값의 비는 강판삽입형 접합부의 경우 0.80~1.10, 강판측재형 접합부는 0.75~1.46이었다. 4. 끝면거리 7 d의 항복하중을 기준으로 강판삽입형 볼트접합부의 경우 12 mm 접합부의 저감계수(Ke)는 0.89, 16 mm는 0.93, 20 mm는 0.85였다. 강판삽입형 드리프트 핀 접합부의 경우 12 mm는 0.89, 16 mm는 0.93, 20 mm는 0.93이었다. 강판측재형 직경 12 mm 볼트접합부의 저감계수는 0.79, 16 mm는 0.80이었다.

• Steel and Composite Structures
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• 제9권2호
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• pp.173-189
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• 2009

This paper presents a study on the behavior and design of bolted stainless steel plates under in-plane tension. Using an experimentally validated finite element (FE) program strength of stainless steel bolted plates under tension is examined with an emphasis on plate bearing mode of failure. A numerical parametric study was carried out which includes examining the behavior of stainless steel plate models with various proportions, bolt locations and in two different material grades. The models were designed to fail particularly in bolt tear-out and material piling-up modes. In the numerical simulation of the models, non-linear stress-strain material behavior of stainless steel was considered by using expressions which represent the full range of strains up to the ultimate tensile strain. Using the results of the parametric study, the effect of variations in bolt positions, such as end and edge distance and bolt pitch distance on bearing resistance of stainless steel bolted plates under in-plane tension has been investigated. Finally, the results obtained are critically examined using design estimations of the currently available international design guidance.

• Steel and Composite Structures
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• 제28권6호
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• pp.681-690
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• 2018

This paper highlights results of some experimental work that deals with strengthening of bolted shear joints in thin-walled ferrocement structure where steel wires, bent into U-shape are considered as simple inserts around the bolt hole. The parameters investigated include the number of layers of wire mesh, edge distance of bolt hole, size and location of the inserts. Test results have shown that for small edge distance, failure occurred either in cleavage or shearing mode, and the strength of the joint increased with an increase in the edge distance. This continued up to an upper limit set by either tension or bearing failure. The experimental study further revealed that for a given edge distance the strength of a joint can significantly be enhanced by using U-inserts. The equations developed for predicting joint strength in ferrocement composites can also be modified to include the effects of the inserts with a good level of accuracy.

• 소성∙가공
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• 제17권6호
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• pp.407-411
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• 2008

A brake system in automobile is one of the important parts that directly affect the safety of passengers. Particularly, disk brake module is applied to almost all kinds of automobile brake system due to its remarkable braking power and braking distance. In the disk brake module of an automobile, the bolt for tire wheel is assembled to the disk brake hub by interference fit(bolt pressing process). The process induces small deformation whose range is within tens of ${\mu}m$ and this deformation may cause the runout badness of the whole disk brake module, and even braking problems such as judder or squeal phenomena which makes the loss of braking efficiency. In this study, bolt pressing fit into hub was simulated by $ANSYS^{TM}$, a commercial structure analysis program. Also, the aspect and the cause of hub displacement were analyzed and the solution for decreasing runout of hub was proposed.

• 한국산학기술학회논문지
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• 제10권10호
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• pp.2831-2836
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• 2009

고장력볼트를 이용한 강부재의 연결부에서 마찰력을 초과하는 설계하중이 작용하여 미끄럼이 발생하는 점을 기점으로 볼트와 모재의 전단강도 및 지압강도에 의해 설계하중을 지지하게 된다. 미끄럼량은 볼트의 장력, 접촉면의 마찰계수, 모재구멍내에서 볼트의 위치에 따라 결정되어 질 수 있다. 본 연구에서는 모재 및 덮개판에 대하여 볼트구멍의 크기를 변화시켜 제작된 고장력볼트 체결부에 순수굽힘과 인장력이 작용하는 경우 표준공과 과대공에 따른 미끄럼을 측정하고 비교분석하였다. 표준공을 가지는 경우보다 과대공을 가지는 경우에 $74\sim94%$ 작은 하중에서 미끄럼이 발생하였다. 인장력을 받는 부재에서는 과대공치수가 클수록 미끄럼 하중비가 작게 나타났으며 모재의 과대공치수가 덮개판의 과대공치수보다 미끄럼하중변화와 연관성이 많은 것으로 나타났다.

• 한국안전학회지
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• 제23권4호
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• pp.19-24
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• 2008

This paper presents and discusses the experimental results on the F10T high strength bolts used in the T-flange joint structure. The experimental works were carried out for the parameters which are flange web thickness, the distance between bolts, prying ratio. The results show that the working stress imposed to bolts decreases as the flange web thickness increases on the other hand the imposed stress to the bolts increases as the distance between two bolts increases. In other words the strength of the T-flange joint increased as the web flange thickness increases and the distance between two bolts decreases. The prying ratio is increased as the distance between two bolts increases and as the flange web thickness decreases However, the degree of stress decrease in flange thickness variation is not that high as the distance variation between two bolts. Finally the equation for predicting the failure stress in T-flange joint structure using F10T high strength bolts was suggested.

• 한국구조물진단유지관리공학회 논문집
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• 제15권5호
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• pp.82-91
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• 2011

본 연구에서는 콘크리트 매입앵커시스템 설계코드인 ACI 349-01에 제시되지 않은 직경 50mm(2") 이상 유효매입깊이($h_{ef}$) 635mm(25") 이상의 대형 매입앵커시스템에서 전단 파열파괴 성능과 거동특성을 파악하기 위하여 24개의 실규모 시험을 하였다. 시험변수로는 앵커볼트의 직경($d_0$=63.5, 76.2, 88.9mm), 앵커볼트의 매입깊이($h_{ef}$=635, 762mm), 연단거리($c_1$=381, 508, 762mm) 그리고 콘크리트강도($f_{ck}$= 38MPa)로 하였다. 예측식인 $V_{aci06}$과 $V_{ccd}$는 시험결과($V_{test}$)를 과대평가하는 것으로 나타났다. 앵커볼트직경($d_0$) 50mm(2")이상, 유효매입깊이($h_{ef}$) 635mm(25")이상의 대형앵커시스템에서 앵커볼트직경 변화시험과 유효매입깊이 변화시험은 앵커시스템의 전단성능에 영향이 없는 것으로 나타났다. 그러나, 대형 앵커리지시스템의 연단거리와 앵커볼트의 직경에 대한 형상비에 의한 분석결과 형상비가 작아질수록(앵커볼트의 직경이 커질수록) 시험결과에 대한 예측식의 비가 커지는 것으로 분석되었다. 이는 앵커볼트의 직경이 전단강도 저하의 직접적인 원인인 것으로 밝혀졌다. 설계기준에 대한 적절한 개선을 위해서는 더 많은 이론적, 해석적 연구가 필요하다.

• Steel and Composite Structures
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• 제18권6호
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• pp.1423-1450
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• 2015

The paper presents the details and results of an experimental study on bolted end-plate joints of industrial type steel building frames. The investigated joints are commonly used in Lindab-Astron industrial buildings and are optimized for manufacturing, erection and durability. The aim of the research was to provide an experimental background for the design model development by studying load-bearing capacity of joints, bolt force distribution, and end-plate deformations. Because of the special joint details, (i.e., joints with four bolts in one bolt-row and HammerHead arrangements), the Eurocode 3 standardized component model had to be improved and extended. The experimental programme included six different end-plate and bolt arrangements and covered sixteen specimens. The steel grade of test specimens was S355, the bolt diameter M20, whereas the bolt grade was 8.8 and 10.9 for the two series. The end-plate thickness varied between 12 mm and 24 mm. The specimens were investigated under pure bending conditions using a four-point-bending test arrangement. In all tests the typical displacements and the bolt force distribution were measured. The end-plate plastic deformations were measured after the tests by an automatic measuring device. The measured data were presented and evaluated by the moment-bolt-row force and moment-distance from centre of compression diagrams and by the deformed end-plate surfaces. From the results the typical failure modes and the joint behaviour were specified and presented. Furthermore the influence of the end-plate thickness and the pretension of the bolts on the behaviour of bolted joints were analysed.