• Computational Structural Engineering
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• v.11 no.4
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• pp.239-251
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• 1998

본 연구에서는 비대칭 박벽단면을 갖는 곡선보의 안정성해석을 수행할 수 있는 이론 및 엄밀해를 제시하기 위하여, 3차원 연속체로부터 유도된 평형방정식으로부터 선형화된 가상일의 원리를 적용하였다. 박벽단면의 구속된 ？(warping)과 곡률효과를 고려하고 유한한 회전각의 2차항을 포함하는 곡선보의 변위장을 도입하여 단면에 대해 적분함으로써 도심축에 대한 박벽 곡선보의 총포텐셜에너지를 유도하였다. 또한, 단순지지되고 일축대칭 단면을 갖는 박벽원형 곡선보의 면내 및 면외좌굴에 대한 엄밀해를 유도하기 위하여, 면내에 대해서는 균일압축을 받는 원형아치의 역대칭 좌굴모드에 대한 좌굴하중을 유도하고 면외좌굴에 대해서는 균일압축 및 순수휨을 받는 아치의 처짐함수를 가정하여 곡선보의 횡좌굴하중에 대한 일반해를 제시하였다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.4A
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• pp.217-225
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• 2012

Structural behavior of built-up compression members with unsymmetric connectors under buckling status has been studied through these experiments. When the distance between adjacent H-300 beams of built-up compression member is 2 m in length, and the H-300 beams are lengthened up to 30 m in length with three-10 m-H-beams by bolts and double arrayed, three specimen having each connector plate, single channel, double channel are experimented for evaluating buckling loads. The buckling loads from the experiments are compared with buckling loads of structural analysis using FEM and buckling loads of Timoshenko Eq. in order to figure out how the connectors' type affects on longitudinal and lateral displacements, also strain of the built-up compression members as well. The result from the experiments show that the buckling loads 4.2% decreases in double channel connectors and 36.6% decreases in single channel connectors than plate connectors.

• Journal of Korean Tunnelling and Underground Space Association
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• v.4 no.1
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• pp.71-78
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• 2002

In this study, the influence of the presence of discontinuity planes on the load transfer mechanism and the pattern of loosening zone was studied based on the laboratory test. The trap-door and the reaction plates are installed as the bottom plane of the model box. The vertical discontinuity plane is installed in the dry sand. Various overburden heights and locations of discontinuity planes are applied as major factors in this study. The results show that at higher overburden heights over about 1.5 times the excavation width, the ratio of the transferred stress to the insitu stress converges to a certain value even if the overburden height increases further. The results also show that the discontinuity plane gives relatively larger influence on the load transfer mechanism, that produces the unsymmetrical load concentration, when the discontinuity plane locates within the tunnel width. When the discontinuity plane locates outside the tunnel width, the unsymmetrical load concentration is reduced considerably.

• Composites Research
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• v.13 no.5
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• pp.18-30
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• 2000

In order to optimize the design of unidirectional fiber reinforced composite C-rings, a viscoelastic load relaxation behavior was analyzed under a point load. Initially, the deflection and bending stiffness were calculated based on the elastic beam theory and the viscoelastic relaxation and creep behaviors were derived from the elastic solution using the correspondence theorem. Besides the orthotropic mechanical properties of the composite, asymmetric mechanical property due to the different tensile and compressive properties were also considered. Except the deviation affected by the relatively large thickness of the specimen compared to the radius, the calculated relaxation showed good agreement with the experimental result.

• Fire Science and Engineering
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• v.25 no.1
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• pp.63-71
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• 2011

When it comes to slim floor using asymmetric H-beam, it was designed that the steel member is embedded in concrete with relatively low thermal conductivity so as to minimize the deterioration of rigidity of steel member in fire. But given the bottom flange of asymmetric H-beam is directly exposed to the fire, the measure of applying the fireproof coating to improve the fire rate performance of slim floor beam was sought. The test was aimed at comparing the fireproof performance by adjusting the load ratio of 0.4 and 0.3, and The test was carried out to identify the 3-hour fire performance by reinforcing the beam as well as applying the fireproof coat, In the wake of comparing the specimen depending on variation of load ratio, lowering load ratio by 0.1 resulted in difference of 12 minutes and deflection was 39 mm. It was able to improve 12 minutes by reinforcing the beam and up to 102.4 mm in deflection.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.7
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• pp.505-511
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• 2020

The circular composite tubes have been used as a main spar of HALE-UAV(High Altitude Long Endurance-Unmanned Air Vehicle). In this paper, an analytical model is presented for the prediction of the failure load of unsymmetrically stiffened circular spar using a modified Brazier approach. This model was used to predict the moment carrying capacity of the unsymmetrically stiffened circular spar. From the results, we can know that a stiffened cap placed in the top sector of a spar increased the bending capabilities. Four point bending tests were conducted to estimate the effect of the cap on the failure load and compared with the proposed model. And numerical simulations were performed to analyze the behavior of stiffened circular spar. Comparisons of the results from the proposed model with those from experiments and numerical modes show good correlation.

• Journal of the Korean GEO-environmental Society
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• v.24 no.10
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• pp.41-49
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• 2023

Structures such as bridge columns installed on the asymmetric ground such as mountain areas and sloping ground are subject to various loads such as wind, temperature, earthquake, and etc. The pile foundation is generally applied to bridge columns on the asymmetric ground in order to stably support structures. The behavior of the pile foundation supporting bridge columns changes due to various load conditions. In particular, ground-pile-structure interactions should be studied to analyze the behavior of the pile foundation that supports bridge columns effected by dynamic loads such as earthquakes. The pile foundation installed on the asymmetric ground effected by the earthquake has the complicated dynamic interaction between the foundation and the ground due to the ground slope, the difference in soil resistance according to the shaking direction, and the ground movements. In this study, the 1g shaking table tests were conducted to confirm the effect of the slope of the sloping ground on the dynamic behavior of group piles supporting the superstructure installed at the berm of the sloping sandy soil which is the asymmetric ground. The result shows that the acceleration of the pile cap and the superstructure decrease as the slope of the sloping ground increase, and the slope of the dynamic p-y curve of the pile decrease.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2002.12a
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• pp.199-202
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• 2002

신경회로망을 동적 정보처리에 응용하기 위해서는 비대칭 결합 신경회로망에서 생성되는 동적 상태천이에 관한 직관적 이해가 필요하다. 자기결합을 갖고 결합하중치가 비대칭인 순환결합형 신경회로망은 복수 개의 리미트사이클이 기억 가능하다는 것이 알려져 있다. 현재까지 이산시간 모델의 네트워크에 대한 상태천이 해석은 상세하게 이루어져 왔다. 그러나 연속시간 모델에 대한 해석은 네트워크 규모의 증가에 따른 급격한 계산량의 증가 때문에 연구가 그다지 활발하게 이루어지지 않고 있다. 본 논문에서는 각 뉴런이 최근접 뉴런에만 이진화된 결합하중 +1 및 -1로 연결된 연속시간모델 순환결합형 신경회로망의 동적인 상태천이 특성을 해석하여 이산시간 모델에서 기억 가능한 리미트사이클과의 차이점을 분석한다. 또한 연속시간 네트워크 모델에 카오스 신호를 인가하여 리미트사이클간의 천이를 제어할 수 있는 가능성을 분석하여 동적정보처리에 네트워크를 응용할 수 있는 가능성을 검토한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.1
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• pp.399-405
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• 2012

This paper investigates the characteristics of buckling loads for steel arches with new type cross section which is consisted of T-section and pipe-section. A general purpose finite-element program ABAQUS was used to evaluate the inelastic buckling strengths of the arches which included the influence of the geometric and material nonlinearity. According to the comparisons between earlier studies and results from finite-element analyses, new design equations should be developed for the new arches. New buckling factors were developed to consider influence of rise-to-span ratio and boundary conditions. It is found that the presented factors are sufficiently accurate to predict the inplane buckling loads of new type section steel arches subjected to uniformly distributed loading. The proposed equations can be used to investigate new type steel arches subjected to unsymmetrical loading and composited arches.

• Journal of the Society of Naval Architects of Korea
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• v.29 no.4
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• pp.193-201
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• 1992

A new equivalent curved beam theory is developed for the analysis of the corner part of ship structures, in which effects of distributed loads and asymmetricity with two or three connected parts are considered. Equivalent loads are obtained from equilibrium conditions between the distributed loads and the member forces and moments at the ends of curved beam. And an equivalent curved beam for the asymmetric structure is obtained by superposing the equivalent symmetric parts which have equivalent stiffness. From the sample calculation, it is found that the results of the new equivalent curved beam theory are well agreed with those of finite element method using membrane elements with little computing time and sufficient accuracy.