• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.8
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• pp.565-571
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• 2020

In this paper, precision and efficient nonlinear structural analysis for the aircraft wing-box model is developed. Herein, nonlinear shell element based on the co-rotational (CR) formulation is implemented. Then, parallel computing algorithm, the element-based partitioning technique is developed to accelerate the computational efficiency of the nonlinear structural analysis. Finally, computational performance, i.e., accuracy and efficiency, of the proposed analysis is evaluated by comparing with that of the existing commercial software.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.660-663
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• 2011

폭발하중은 매우 짧은 시간 내에 순간적인 높은 압력으로 발생된다. 따라서 폭발하중을 받는 구조물은 매우 복잡한 순간 동역학적 손상 거동을 나타낸다. 이러한 외부 하중에 대한 실험적 연구는 큰 비용, 시설, 그리고 군사적 보안 문제가 요구되기 때문에, 고성능 컴퓨팅 기술을 이용한 수치적 기법을 통해 구조물의 동적 비선형 해석을 수행하였다. 수치해석의 정확성을 높이기 위해 폭풍파와 같은 대기전파의 경우 Euler 기법, 콘크리트 재료의 경우 Lagrange 기법을 적용한 복합적 수치해석 (multi-solver coupling) 기법이 적용되었다. 제안된 수치해석 기법은 explicit 유한요소해석 프로그램인 AUTODYN을 이용하여 수행되었다. 그리고 클러스터 (cluster) 내 병렬 알고리즘 (parallel algorithm)을 이용하여 수치해석의 효율성을 높였다. RC 구조물의 수치해석 결과, 기존 실험 결과와 비교하여 잘 일치되었다. 또한 영역분할 개수가 증가할수록 수행시간은 감소되었고 Speed-up과 효율성은 높아졌다.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.12 no.3
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• pp.385-396
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• 1999

In the process of structural design for large-scale structures with several thousands of degrees of freedom, a plethora of structural calculations with large amount of data storage are required to obtain the forces and displacements of the members. However, current computational environment with single microprocessor such as a personal computer or a workstation is not capable of generating a high-level of efficiency in structural analysis and design process for large-scale structures. In this paper, a high-performance parallel computing system interconnected by a network of personal computers is proposed for an efficient structural analysis. Two distributed structural analysis algorithms are developed in the form of distributed or parallel preconditioned conjugate gradient (DPCG) method. To enhance the performance of the developed distributed structural analysis algorithms, the number of communications and the size of data to be communicated are minimized. These algorithms are applied to the structural analyses of three large space structures as well as a 144-story tube-in-tube framed structure.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.12 no.2
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• pp.233-241
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• 1999

본 연구는 개별 메모리를 갖는 소결합 구조의 MIMD형 병렬컴퓨터인 트랜스퓨터시스템 하에서 구조최적화를 위한 병렬처리 과정을 보이고 시험모델에 적용하여 타당성 및 효율성을 검증한다. 전체 최적화과정의 대부분을 차지하는 해석 및 민감도 알고리즘은 영역단위의 병렬성을 갖는 부구조화에 근거하고 하드웨어 구성에 맞춰 변환 재구성한다. 각 노드간 통신은 정적응축과 설계도함수에 한정, 그 횟수를 최소화하고 그들을 동기화하므로써 개별메모리형 연산모델의 약점인 통신비용의 문제를 해소한다. PC를 호스트로 한 수치실험은 고속화 효율성 면에서 고무적인 결과를 보여주고 있으며, 이런 점에서 시스템의 확장성을 함께 고려한다면 트랜스퓨터 시스템에 기초한 병렬처리는 공학 환경의 변화와 요구에 부응하는 좋은 대안이 될 수 있다.

• Journal of KSNVE
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• v.6 no.4
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• pp.410-413
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• 1996

초병렬처리는 컴퓨팅의 신기술로서 앞으로 유망한 수단이며 조만간에 보편화 될 전망이다. 이미 유동이나 연소 해석, 비선형 구조해석 등의 분야에서 병렬 프로 그래밍 연구가 활발해지고 있고, 상요 소프트웨어 업체들에서 parting작업을 시작 하였다. 음향해석에 관련된 학자나 연구원들이 지금부터라도 관심을 기울이면 세계 의 수퍼컴퓨팅 신기술 조류에 시작단계에서 동참할 수 있다.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.26 no.4
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• pp.283-292
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• 2013

The objective of this research is to evaluate of global and local damage for steel-concrete composite structures under highway bridge exposed to fire loading. To enhance the accuracy and efficiency of the numerical analysis, the proposed transient nonlinear thermal structure interaction(TSI) parallel fire analysis method is implemented in ANSYS. To validate the TSI parallel fire analysis method, a comparison is made with the standard fire test results. The proposed TSI parallel fire analysis method is applied to fire damage analysis and performance evaluation for Buchen highway bridge. The result of analysis, temperature of low flange and web are exceed the critical temperature. The deflection and deformation state show good agreement with the fire accident of buchen highway bridge.

• Computational Structural Engineering
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• v.9 no.4
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• pp.5-10
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• 1996

본 고에서는 paragon에서 DYNA3D 결과의 검증과 효율성을 점검하였는데, 적절한 CPU 개수를 선택하여 계산할 때는 Cray에 비하여 더욱 빠른 시간 내에 해석결과를 얻을 수 있을 뿐만 아니라 본 고에서 언급되지는 않았지만 Cray에서는 풀 수 없는 아주 큰 memory를 요구하는 문제도 paragon의 DYNA3D를 이용하면 급속히 확산될 추세이며 이에 따라 기존의 응용 소프트웨어의 병렬화는 필연적인 결과라고 생각된다. 따라서 병렬컴퓨터 및 병렬 프로그래밍에 대한 이해를 통하여 미래의 시뮬레이션 분야에서 앞서갈 수 있는 능력을 갖추는 노력이 절실히 요구된다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.2
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• pp.41-50
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• 2003

In this paper, nonlinear parallel structural analyses are introduced by using the parallel multifrontal solver and damage localization for 2D and 3D crack models is presented as the application of nonlinear parallel computation. The parallel algorithms related with nonliear reduce the amount of memory used is carried out because many variables should be utilized for this highly nonlinear damage analysis. Also, Riks' continuation method is parallelized to search the solution when strain softening occurs due to damage evolution. For damage localization problem, several computational models having up to around 1-million degree of freedoms are used. The parallel performance in this nonlinear parallel algorithm is shown through these examples and the local variation of damage at crack tip is compared among the models with different degree of freedoms.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.2
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• pp.133-140
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• 2018

In this paper, we develop an automated software for in-plane structural analysis of composite laminated structures. The developed software supports various failure criteria and reports the analysis results considering user's convenience. It also provides batch job analysis function based on parallel processing technique. To verify the performance of the software, we compared margin of safety(MS) calculated in the software to those obtained from in-house method and the specimen experiment. As a result of comparisons, there was an error of less than 0.01 in the in-house method and it is within about ${\pm}10%$ with the specimen experiment. In addition, we confirmed the improvement of execution speed of batch job analysis based on parallel processing technique.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.22 no.1
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• pp.35-44
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• 2009

This paper describes an application of domain decomposition method for parallel finite element analysis which is required to large scale 3D structural analysis. A parallel finite element method system which adopts a domain decomposition method is developed. Node is generated if its distance from existing node points is similar to the node spacing function at the point. The node spacing function is well controlled by the fuzzy knowledge processing. The Delaunay triangulation method is introduced as a basic tool for element generation. Domain decomposition method using automatic mesh generation system holds great benefits for 3D analyses. Aa parallel numerical algorithm for the finite element analyses, domain decomposition method was combined with an iterative solver, i.e. the conjugate gradient(CG) method where a whole analysis domain is fictitiously divided into a number of subdomains without overlapping. Practical performance of the present system are demonstrated through several examples.