• 대한기계학회논문집A
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• 제30권5호
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• pp.585-594
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• 2006

The joined-wing is a new concept of the airplane wing. The fore-wing and the aft-wing are joined together in a joined-wing. The range and loiter are longer than those of a conventional wing. The joined-wing can lead to increased aerodynamic performance and reduction of the structural weight. In this research, dynamic response optimization of a joined-wing is carried out by using equivalent static loads. Equivalent static loads are made to generate the same displacement field as the one from dynamic loads at each time step of dynamic analysis. The gust loads are considered as critical loading conditions and they dynamically act on the structure of the aircraft. It is difficult to identify the exact gust load profile. Therefore, the dynamic loads are assumed to be (1-cosine) function. Static response optimization is performed for the two cases. One uses the same design variable definition as dynamic response optimization. The other uses the thicknesses of all elements as design variables. The results are compared.

• 오토저널
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• 제15권1호
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• pp.107-119
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• 1993

The objective of this study is to analyze the static and dynamic characteristics of automotive rubber components by computer simulation. Bush / rectangular type engine mounts and wind shield weather strip are analyzed by using the commercial code ABAQUS and the results are verified by experiments. Large deformation static response is analyzed in order to get the information about the deformation pattern and static stiffness of engine mounts, and about the seperation force of wind shield weather strip from body. The isothermal steady-state dynamic response of components which have been subjected to an initial static pre-load is analyzed for the dynamic stiffness of engine mount rubber components. There are good agreements between simulation and experiments. So it is possible to apply the computer simulation to the design of automotive rubber components.

• Wind and Structures
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• 제21권6호
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• pp.609-623
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• 2015

Seismic reliability analysis of a jacket-type support structure for an offshore wind turbine was performed. When defining the limit state function by using the dynamic response of the support structure, a number of dynamic calculations must be performed in a First-Order Reliability Method (FORM). That means analysis costs become too high. In this paper, a new reliability analysis approach using a static response is used. The dynamic effect of the response is considered by introducing a new parameter called the Peak Response Factor (PRF). The probability distribution of PRF can be estimated by using the peak value in the dynamic response. The probability distribution of the PRF was obtained by analyzing dynamic responses during a set of ground motions. A numerical example is presented to compare the proposed approach with the conventional static response-based approach.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.999-1004
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• 2004

A numerical method and algorithms is proposed to perform optimization of non-linear response structures. An analytical and numerical method based finite element method is also proposed for the transformation of non-linear response into linear response. Loads transformed from this method are defined as the equivalent linear loads. With the loads and the transformed response, linear static optimization is performed for nonlinear response structure with geometric and/or material non-linearity. The results of the optimization are compared with them of typical non-linear response optimization using finite difference method. The proposed method is very efficient and derives good solution.

• Structural Engineering and Mechanics
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• 제46권5호
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• pp.695-711
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• 2013

It is reasonable to assume that reinforced concrete (RC) structures enter the nonlinear range of response during a severe ground motion. Numerical analysis to predict the behaviour therefore must allow for the presence of nonlinear deformations if an accurate estimate of seismic response is aimed. Among the factors contributing to inelastic deformations, the influence of the degradation of the bond slip phenomenon is important. Any rebar slip generates an additional rotation at the end regions of structural members which are not accounted for in a conventional analysis. Although these deformations could affect the seismic response of RC structures considerably, they are often neglected due to the unavailability of suitable models. In this paper, the seismic response of two types of RC structures, designed according to the Iranian concrete code (ABA) and the Iranian seismic code (2800), are evaluated using nonlinear dynamic and static analyses. The investigation is performed using nonlinear dynamic and static pushover analysis considering the deformations due to anchorage slip. The nonlinear analysis results confirm that bond slip significantly influences the seismic behavior of RC structure leading to an increase of lateral deformations by up to 30% depending on the height of building. The outcomes also identify important parameters affecting the extent of this influence.

• Structural Engineering and Mechanics
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• 제69권5호
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• pp.567-577
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• 2019

Guyed steel lattice towers (or guyed masts) are widely used for supporting antennas for telecommunications and broadcasting. This paper presents a numerical study on the static and dynamic response of guyed towers. Three-dimensional nonlinear finite-element models are used to simulate the response. Through performing static pushover analyses and free-vibration (modal) analyses, the effect of different bracing configurations is investigated. In addition, seismic analyses are performed on towers of different heights to study the influence of earthquake excitation time-lag (or the earthquake travel distance between tower anchors) and antenna weight on the seismic response of guyed towers. The results show that the inclusion of time lag in the seismic analysis of guyed towers can influence shear and moment distribution along the height of the mast. Moreover, it is found that the lateral response is insensitive to bracing configurations. The results also show that, depending on the mast height, an increased antenna weight can reduce the tower maximum base shear while other response quantities, such as cables tension force are found to be insensitive to variation in the antenna weight.

• 한국산학기술학회논문지
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• 제9권5호
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• pp.1095-1101
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• 2008

본 연구에서는 LNG 저장탱크에 대하여 내진해석을 수행하였다. 해석 모델은 관통 파이프만을 고려한 경우와 관통 파이프, 내부 벽체, 가이드를 고려한 경우에 대하여 해석을 수행하였다. 내진 해석법으로 등가정적 해석법과 응답 스펙트럼 해석법을 두 가지 해석 모델에 대하여 각각 적용하였다. 변형량과 응력을 계산하고, 그 결과를 비교하였다. 해석 결과, 응답 스펙트럼 해석법이 등가정적 해석법에 비하여 LNG 저장탱크를 보다 잘 모사하는 방법임을 알 수 있었다.

• Advances in Computational Design
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• 제2권3호
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• pp.143-163
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• 2017

This paper presents a non-destructive testing method for estimating the structural response of cable-stayed footbridges. The approach combines field measurements with a numerical static analysis of the structure. When the experimental information concerning the structure deformations is coupled with the numerical data on the structural response, it is possible to calculate the static forces and the design tension resistance in selected structural elements, and as a result, assess the condition of the entire structure. The paper discusses the method assumptions and provides an example of the use of the procedure to assess the load-carrying capacity of a real steel footbridge. The proposed method can be employed to assess cable-stayed structures including those made of other materials, e.g., concrete, timber or composites.

• Wind and Structures
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• 제31권5호
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• pp.459-472
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• 2020

This study focused on the non-synoptic, tornado-like wind-induced effects on flexible horizontal structures that are extremely sensitive to winds. More specifically, the nonuniform, intensive vertical wind-velocity and transient natures of tornado events and their effects on the global behavior of a long-span bridge were investigated. In addition to the static part in the modeling of tornado-like wind-induced loads, the motion-induced effects were modeled using the semi-empirical model with a two-dimensional (2-D) indicial response function. Both nonlinear wind-induced static analysis and linear aeroelastic analysis in the time domain were conducted based on a 3-D finite-element model to investigate the bridge performance under the most unfavorable tornado pattern considering wind-structure interactions. The results from the present study highlighted the important effects due to abovementioned tornado natures (i.e., nonuniform, intensive vertical wind-velocity and transient features) on the long-span bridge, and hence may facilitate more appropriate wind design of flexible horizontal structures in the tornado-prone areas.

• 태양에너지
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• 제19권3호
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• pp.75-83
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• 1999

The optimum drive control method have to be developed to exhibit the use object contributed trust, accuracy, amenity and energy save of product. To develop the optimum drive control method is, first, grasped the static characteristics for the entire system combined each element which consists the machine and performed the dynamic characteristics explanation based on the satisfied result which acquires at the static characteristics explanation. According to this explanation, the response of the system shows same characteristics tendency and the increasing same quantify comparing to response change of each element. So the dynamic response of the entire system shows different. Therefore this study performs the static and the dynamic characteristic explanation of entire system and each element for using air-conditioning system of solar energy based on the performed result from now on, so for application of this result.