• Structural Engineering and Mechanics
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• 제56권6호
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• pp.1063-1093
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• 2015

Structural robustness has become an important design variable. However, based on the existing definitions of structural robustness it is often difficult to analyse and evaluate structural robustness, and sometimes not efficient since they mix structural robustness with several other structural variables. This paper concerns the development of a new structural robustness definition, and structural robustness and structural fragility indices. The basis for the development of the new indices is the analysis of the damage energy of structural systems for a given hazard scenario and involves a criterion to define an "unavoidable collapse" state. Illustrative examples are given detailing the steps and calculations needed to obtain values for both the structural robustness and the structural fragility indices. Finally, this paper presents the main advantages of the newly proposed definition and indices for the structural risk analysis over existing traditional methods.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.500-507
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• 2006

Recently, the structural design code has been changed and every buildings, which have more than three floors or wider area than 1,000m2, should be designed to be able to resist earthquakes. However, most structural engineers are working in some big cities and this physical distance would set a barrier between structural engineers and architects. As a result, most row-rise buildings in small cities are designed and constructed without structural design or the consulting by structural engineers. The purpose of this research is to develop an web-based structural design environment in which structural design and consulting can be performed efficiently through on-line communication without off-line meetings or documents. In addition to the on-line communication, the system has a integrated structural design module which supports all the process of structural design and can increases the productivity of structural design work.

• Smart Structures and Systems
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• 제15권2호
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• pp.409-424
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• 2015

Structural nonlinearity is a common phenomenon encountered in engineering structures under severe dynamic loading. It is necessary to localize and identify structural nonlinearities using structural dynamic measurements for damage detection and performance evaluation of structures. However, identification of nonlinear structural systems is a difficult task, especially when proper mathematical models for structural nonlinear behaviors are not available. In prior studies on nonparametric identification of nonlinear structures, the locations of structural nonlinearities are usually assumed known and all structural responses are measured. In this paper, an identification algorithm is proposed for locating and identifying model-free structural nonlinearities and systems using incomplete measurements of structural responses. First, equivalent linear structural systems are established and identified by the extended Kalman filter (EKF). The locations of structural nonlinearities are identified. Then, the model-free structural nonlinear restoring forces are approximated by power series polynomial models. The unscented Kalman filter (UKF) is utilized to identify structural nonlinear restoring forces and structural systems. Both numerical simulation examples and experimental test of a multi-story shear building with a MR damper are used to validate the proposed algorithm.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1995년도 봄 학술발표회 논문집
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• pp.160-169
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• 1995

This study presents an application of object-oriented methodology for structural dcsign process. A prototype system of integrated a structural design system is developed by introducing a structural analysis object model(SAOM) and structural design object model(SDOM). The SAOM module. which is modeled as a part of structural member, performs structural analysis using FEM approach and the SDOM module checks structural members based on Korea steel design standard. Above mentionedmodelsareabstraclencapsulatibleandreusable.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1994년도 가을 학술발표회 논문집
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• pp.137-144
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• 1994

This study describes an application of a knowledge-based system for a part of the development of an integrated structural design system. In preliminary structural design procedure, most structural design operation are performed by structural engineer's manual method. These lack of systematic operation hampers the effective system integration. By introducing expert system to the structural planning stage, structural engineer can automate structural Planning process of an integrated structural design system for complex design. Engineering data management is receiving increasing attention due to complexity of information necessary for performing structural engineering operations. So, in this paper, we describe a methodology for automating conceptual structural design and developing a knowledge-based system integrated with database. At the end, we use an implemented example to support our methodology.

• 전산구조공학
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• 제8권3호
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• pp.123-133
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• 1995

본 연구는 통합 구조설계 시스템의 구축에서 객체지향적인 방법론을 도입하여 건축 구조물을 객체모델링하고, 구조해석 객체모델(Structural Analysis Object Model, SAOM)과 구조설계 객체모델(Structural Design Object Model, SDOM)을 개발하여 통합 구조설계 시스템의 원형(Prototype)을 제시한다. 구조해석 객체모델은 구조부재를 모델링한 것으로 유한요소법을 이용하역 구조물의 해석을 실시하며, 구조설계 객체모델은 한국 강구조 기준에 의해 구조부재의 적합성을 검토하도록 모델링 하였다. 이 두 모델은 통합 구조설계 시스템을 구축하는데 유용하도록 의미 추상적이고, 캡슐화되고, 재사용성이 높다.

• International Journal of Aerospace System Engineering
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• 제3권1호
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• pp.17-20
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• 2016

In this work, a structural design on horizontal axis wind turbine blade using natural flax fiber composite is performed. The structural design results of flax/epoxy composite blade are compared with the design results of glass/epoxy composite blade. In order to evaluate the structural design of the composite blade, the structural analysis was performed by the finite element method. Through the structural analyses, it is confirmed that the designed blade using natural composite is acceptable for structural safety, blade tip deflection, structural stability, resonance possibility, and weight. Finally, structural test of manufactured blade was performed. Through the structural test, it is confirmed that the designed blade is acceptable.

• 항공우주시스템공학회지
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• 제17권5호
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• pp.58-62
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• 2023

본 연구에서 항공기 엔진 내부 구성품의 구조 설계 결과에 대한 구조 안전성 평가 연구를 수행하였다. 엔진 내부 구성품에 라디에이터와 인터쿨러가 장착된다. 따라서 비행중에 라디에이터와 인터쿨러의 안전성을 검토하였다. 구조 해석을 통해 구조 안전성을 평가하였다. 구조 해석 기법은 유한 요소 해석 기법을 활용하였다. 구조 설계 및 해석을 위하여 가속도 하중을 고려하였다. 구조 안전성 평가 결과 구조 설계 결과는 타당한 것으로 확인되었다.

• Structural Engineering and Mechanics
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• 제52권1호
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• pp.19-33
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• 2014

Structural robustness refers to the ability of a structure to avoid disproportionate consequences to the original cause. Currently attentions focus on the concepts of structural robustness, and discussions on methods of robustness based structural design are rare. Firstly, taking basis in robust $H_{\infty}$ control theory, structural robustness is assessed by $H_{\infty}$ norm of the system transfer function. Then using the SIMP material model, robustness based design of grid structures is formulated as a continuum topology optimization problem, where the relative density of each element and structural robustness are considered as the design variable and the optimization objective respectively. Generalized elitist genetic algorithm is used to solve the optimization problem. As examples, robustness configurations of plane stress model and the rectangular hyperbolic shell model were obtained by robustness based structural design. Finally, two models of single-layer grid structures were designed by conventional and robustness based method respectively. Different interference scenarios were simulated by static and impact experiments, and robustness of the models were analyzed and compared. The results show that the $H_{\infty}$ structural robustness index can indicate whether the structural response is proportional to the original cause. Robustness based structural design improves structural robustness effectively, and it can provide a conceptual design in the initial stage of structural design.

• Structural Engineering and Mechanics
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• 제54권2호
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• pp.291-304
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• 2015

Compared with the identification of linear structures, it is more challenging to conduct identification of nonlinear structure systems, especially when the locations of structural nonlinearities are not clear in structural systems. Moreover, it is highly desirable to develop methods of parametric identification using partial measurements of structural responses for practical application. To cope with these issues, an identification method is proposed in this paper for the detection and parametric identification of structural nonlinear restoring forces using only partial measurements of structural responses. First, an equivalent linear structural system is proposed for a nonlinear structure and the locations of structural nonlinearities are detected. Then, the parameters of structural nonlinear restoring forces at the locations of identified structural nonlinearities together with the linear part structural parameters are identified by the extended Kalman filter. The proposed method simplifies the identification of nonlinear structures. Numerical examples of the identification of two nonlinear multi-story shear frames and a planar nonlinear truss with different nonlinear models and locations are used to validate the proposed method.