• Journal of the Korean Wood Science and Technology
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• 제45권6호
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• pp.728-736
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• 2017

In this study, the bending behavior of cross-laminated timber (CLT) connected by nails were investigated. Especially, the load-carrying capacity of the nail-jointed CLT under out-of-plane bending was predicted by the lateral resistance of the used nails. Three-layer nail-jointed CLT specimens and a nail connection were manufactured by 30 mm (thickness) ${\times}$ 100 mm (width) domestic species (Pinus koraiensis) laminas and Ø$3.15{\times}82mm$ nails using a nail-gun. Shear test for evaluating the nail lateral resistance and bending test for evaluating the load-carrying capacity of the nail-jointed CLT under out-of-plane bending were carried out. As a result, two lateral resistance of the used nail, the 5% fastener offset value and the maximum value, were 913 N and 1,534 N, respectively. The predicted load-carrying capacity of the nail-jointed CLT by the 5% offset nail lateral resistance was similar to the yield points on the actual load-displacement curve of the nail-jointed CLT specimens. Meanwhile, the nail-jointed CLT specimens were not failed until the tension failure of the bottom laminas occurred beyond the maximum lateral resistance of the nails. Thus, the measured maximum load carrying capacities of the nail-jointed CLT specimens, approximately 12,865 N, were higher than the predicted values, 7,986 N, by the maximum nail lateral resistance. This indicates that the predicted load-carrying capacity can be used for designing a structural unit such as floor, wall and roof able to support vertical loads in a viewpoint of predicting the actual capacities more safely.

• 한국구조물진단유지관리공학회 논문집
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• 제21권3호
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• pp.60-68
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• 2017

교량은 사회간접시설물의 핵심이 되는 도로의 주요 시설물이므로 공용기간 동안 안정성과 사용성이 확보될 수 있도록 건설되며, 교량의 안전성 확보를 위하여 현재 상태에서 건전성을 평가하는 것은 유지관리 업무에서 중요한 과제이다. 일반적으로 교량의 내하력 평가를 위해 차량재하시험을 통하여 횡분배율을 측정함으로써 교량의 중첩거동 및 대칭거동을 확인할 수 있다. 그러나 공용중인 교량의 횡분배율을 측정하기 위하여 정적재하시험을 수행하고 있으며 교통통제의 어려움이 있다. 따라서 본 연구에서는 동적재하시험 및 상시진동시험에서 측정된 교량의 변위응답 데이터를 경험적 모드분해기법을 이용하여 정적 성분의 변위를 추출하였다. 추출된 정적 성분의 변위를 이용하여 횡분배율을 추정하였으며, 정적재하시험에서 측정된 횡분배율과 비교하였다.

• Earthquakes and Structures
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• 제17권2호
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• pp.221-232
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• 2019

Material non-linearity of Reinforced Concrete (RC) framed structures is studied by modelling concrete using the Concrete Damage Plasticity (CDP) theory. The stress-strain data of concrete in compression is modelled using the Hsu model. The structures are analyzed using a finite element approach by modelling them in ABAQUS / CAE. Single bay single storey RC frames, designed according to Indian Standard (IS):456:2000 and IS:13920:2016 are considered for assessing their maximum load carrying capacity and failure behavior under the influence of gravity loads and lateral loads. It is found that the CDP model is effective in predicting the failure behaviors of RC frame structures. Under the influence of the lateral load, the structure designed according to IS:13920 had a higher load carrying capacity when compared with the structure designed according to IS:456. Ultra High Performance Fiber Reinforced Concrete (UHPFRC) strip is used for strengthening the columns and beam column joints of the RC frame individually against lateral loads. 10mm and 20mm thick strips are adopted for the numerical simulation of RC column and beam-column joint. Results obtained from the study indicated that UHPFRC with two different thickness strips acts as a very good strengthening material in increasing the load carrying capacity of columns and beam-column joint by more than 5%. UHPFRC also improved the performance of the RC frames against lateral loads with an increase of more than 3.5% with the two different strips adopted. 20 mm thick strip is found to be an ideal size to enhance the load carrying capacity of the columns and beam-column joints. Among the strengthening locations adopted in the study, column strengthening is found to be more efficient when compared with the beam column joint strengthening.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2005년도 춘계 학술발표회 논문집
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• pp.583-591
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• 2005

The ship plating is generally subjected to combined in-plane load and lateral pressure loads. In-plane loads include axial load and edge shear, which are mainly induced by overall hull girder bending and torsion of the vessel. Lateral pressure is due to water pressure and cargo. These load components are not always applied simultaneously, but more than one can normally exist and interact. Hence, for more rational and safe design of ship structures, it is of crucial importance to bitter understand the interaction relationship of the buckling and ultimate strength for ship plating under combined loads. Actual ship plates are subjected to relatively small water pressure except for the impact load due to slamming and panting etc. The present paper describes an accurate and fast procedure for analyzing the elastic-plastic large deflection behavior up to the ultimate limit state of ship plates under combined loads. In this paper, the ultimate strength characteristics of plates under axial compressive loads and lateral pressure loads are investigated through ANSYS elastic-plastic large deflection finite element analysis with varying lateral pressure load level.

• 한국자동차공학회논문집
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• 제10권2호
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• pp.166-173
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• 2002

The wheel bearing hub unit is developed type of wheel bearing unified with the hub parts. It has advantage of reducing the weight and the number of components. And, it also improves uniformity of manufacturing quality, In order to design the wheel bearing hub units, many techniques are used such as load analysis, structure analysis and bearing characteristics analysis and so forth. These techniques need highly accurate load conditions founded on service conditions. In this study, to design the wheel bearing hub units used widespread in passenger cars, the service load was measured through driving tests on the public roads and in the special events. The public roads are classified into highway, intercity road, rural road, urban road, and unpaved road so as to know what the characteristics of the road loads are. The results of the tests showed that the wheel force was relative to the lateral acceleration, and also could be calculated from the lateral acceleration. The lateral acceleration was measured from 0.0G to 0.6G in general driving on the public roads, with different distributions in each road type. In special events, the maximum lateral acceleration was measured from 0.8G to 1.3G.

• Geomechanics and Engineering
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• 제29권6호
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• pp.645-655
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• 2022

Granular columns have recently found widespread use in underground construction. The behaviour of granular columns under vertical loads has been extensively studied, specifically in relation to vertical load capacity obtained by bulging of the column body, including the behaviour after encasement of material. Determining the shear strength of loose soils reinforced with granular columns has received less attention. After the observations of lateral deformation near the toe of the embankment, attempts have been made to strengthen the lateral strength of granular columns. The purpose of this research is to look into the effects of different encasement conditions on the lateral load capacity of granular columns. This was accomplished by three-dimensional finite element analysis with FEM software. Various normal pressures and two different encasement configurations, namely single layer encasement and double layer encasement, with differing tensile strengths, were used in this study to determine their effect on lateral resistance. The failure envelope for a single column planted in loose sand was used to analyse the findings for three different granular column diameters, as well as the impact of different encasement conditions. According to the findings, the inclusion of a Granular Column enhanced the shear strength and overall stiffness of the loose sand bed, and the encasement of the Granular Column helped in deriving higher lateral resistance.

• Earthquakes and Structures
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• 제26권6호
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• pp.489-499
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• 2024

Infill masonry walls are vulnerable to lateral loads, including seismic, wind, and concentrated push loads. Various strengthening metal fittings have been proposed to improve lateral load resistance, particularly against seismic loads. This study introduces the use of post-compressed wedges as a novel reinforcement method for infill masonry walls to enhance lateral load resistance. The resistance of the infill masonry wall against lateral-concentrated push loads was assessed using an out-of-plane push-over test on specimens sized 2,300×2,410×190 mm³. The presence or absence of wedges and wedge spacing were set as variables. The push-over test results showed that both the unreinforced specimen and the specimen reinforced with 300 mm spaced wedges toppled, while the specimen reinforced with 100 mm spaced wedges remained upright. Peak loads were measured to be 0.74, 29.77, and 5.88 kN for unreinforced specimens and specimens reinforced with 100 mm and 300 mm spaced wedges, respectively. Notably, a tighter reinforcement spacing yielded a similar strength, as expected, which was attributed to the increased friction force between the masonry wall and steel frame. The W-series specimens exhibited a trend comparable to that of the displacement ductility ratio. Overall, the findings validate that post-compressed wedges improve the out-of-plane strength of infill masonry walls.

• 한국지반신소재학회논문집
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• 제12권4호
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• pp.99-107
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• 2013

매입말뚝의 수평저항 특성을 고찰하기 위하여 매입말뚝에 대한 수평재하시험을 실시하여 수평하중과 수평변위관계를 분석하였다. 말뚝수평재하시험은 시멘트 밀크가 말뚝매입길이의 50%, 70%, 100%로 주입된 6개의 말뚝에 대하여 실시하였다. 시멘트 밀크의 주입비(시멘트 밀크 주입길이/말뚝의 길이)는 매입말뚝의 수평변위, 항복하중, 수평지지력에 큰 영향을 미치는 것으로 나타났다. 시멘트 밀크의 주입비가 증가할수록 매입말뚝의 수평변위가 발생되기 시작하는 위치는 지표면에 가까워지며 말뚝의 수평변위는 감소한다. 그리고 말뚝의 수평지지력과 항복하중은 시멘트 밀크 주입비가 증가할 수록 크게 나타났다. 시멘트 밀크 주입비가 1인 매입말뚝의 항복하중과 극한수평지지력은 시멘트 밀크 주입비가 0.5인 경우보다 약 2~3배 정도 크게 나타났다.

• Coupled systems mechanics
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• 제9권1호
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• pp.29-46
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• 2020

In this paper we deal with stability problems of any complex structure that can be modeled by beam and shell finite elements. We use for illustration the steel plate girders, which are used in bridge construction, and in industrial halls or building construction. Long spans, slender cross sections exposed to heavy loads, are all critical design points engineers must take into account. Knowing the critical load that will cause lateral torsional buckling of the girder, or load that can lead to web buckling, as an important scenario to consider in a design process.Many of such problem, including lateral torsional buckling with influence of lateral supports and their spacing on critical load can be solved by the proposed method. An illustrative study of web buckling also includes effects of position and spacing of transverse and longitudinal web stiffeners, where stiffeners can be modelled optionally using shell or frame elements.

• 한국지반공학회지:지반
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• 제13권5호
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• pp.59-74
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• 1997

본 논문은 낙동강 유역의 사질토 지반에서 수평하중을 받는 강관 말둑의 수평거동을 모형실첨을 통해 관찰하였다. 븐 연구의 목적은 말뚝의 수평거동(하중-변위 잔계,지반내 말뚝의 모멘트 분포, 최대 모멘트-변위 관계 등)에 대한 말뚝의 강성, 말뚝의 근입길이, 지반의 상대밀도, 하중 재하속도, 말뚝두부의 구속조건, 그리고 지반내의 비균질토의 영향에 관하여 실험적인 연구를 수행하고 이러한 영향들을 정량화 할 수 있는 결과들을 얻고자 한다. 비선형적인 하중-변위 관계는 모형실험의 결과들로부터 2차 곡선방정식으로 회귀분석하여 구하였으며, 임의 수평 변위에 대한 수평하중, 항복하중, 극한하중 그리고 최대 휭모멘트와 항복쉽모멘트는 상대밀도를 포함하는 지수함수식의 형태로 회귀분석하여 구하였다. 수평 극한하중에 관한 Brom's의 이론 결과와 실험결과 비교에서, 짧은 말뚝과 긴 말뚝의 결과가 서로 반대로 나타난 것은 가정한 지반반력이 깊은 지점에서 낙동강 사질토의 지반반력보다 작아서 나타나는 것으로 판단된다. 균질충과 비균질토 지반의 수평거동 비교에서, 하부지반의 상 대밀도보다 상부지반의 상대 밀도가 하중-변위관계에 더 큰 영향을 끼치고 있으며, 하부와 상부 지반의 상대밀도 차가 클수록 그런현상은 뚜렷하게 나타났다.