• Structural Engineering and Mechanics
• /
• v.56 no.6
• /
• pp.1063-1093
• /
• 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.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2006.04a
• /
• pp.500-507
• /
• 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
• /
• v.15 no.2
• /
• pp.409-424
• /
• 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.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 1995.04a
• /
• pp.160-169
• /
• 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.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 1994.10a
• /
• pp.137-144
• /
• 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.

• Computational Structural Engineering
• /
• v.8 no.3
• /
• pp.123-133
• /
• 1995

This study presents an application of object-oriented methodology for structural design process. A prototype of integrated structural design system is developed by introducing a structural analysis object model(SAOM) and structural design object model (SDOM). This SAOM module, which models structural member, performs structural analysis using FEM approach and the SDOM module checks structural members based on Korea steel design standard. The abstraction, encapsulation and reusability properties of the proposed models are in establishing the integrated structural design system.

• International Journal of Aerospace System Engineering
• /
• v.3 no.1
• /
• pp.17-20
• /
• 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.

• Journal of Aerospace System Engineering
• /
• v.17 no.5
• /
• pp.58-62
• /
• 2023

In this work, the structural integrity was investigated of the structural design results of internal components for the aircraft engine. The radiator and intercooler were combined with the internal components of the engine. Therefore, the safety of the radiator and intercooler was investigated during flight conditions. The structural integrity was evaluated through structural analysis, using the finite element analysis method. The acceleration load for structural design and analysis was considered. The structural safety evaluation found the structural design results to be valid.

• Structural Engineering and Mechanics
• /
• v.52 no.1
• /
• pp.19-33
• /
• 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
• /
• v.54 no.2
• /
• pp.291-304
• /
• 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.