• 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.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2000.10a
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• pp.307-314
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• 2000

A parallel condensation algorithm for efficient dynamic analysis of three-dimensional large-scale structures is presented. The algorithm is developed for a user-friendly and cost effective high-performance computing system on a collection of Pentium processors connected via a 100 Mb/s Ethernet LAN. To harness the parallelism in the computing system effectively, a large-scale structure is partitioned into a number of substructures equal to the number of computers in the computing system Then, for reduction in the size of an eigenvalue problem the computations required for static condensation of each substructure is processed concurrently on each slave computer. The performance of th proposed parallel algorithm is demonstrated by applying to dynamic analysis of a three dimensional structure. The results show that how the parallel algorithm facilitates the efficient use of a small number of low-cost personal computers for dynamic analysis of large-scale structures.

• Computational Structural Engineering
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• v.28 no.1
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• pp.35-41
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• 2015

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.04a
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• pp.61-68
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• 2001

A parallel nonlinear analysis program of prestressed concrete frame is migrated on a PC cluster system and a massively parallel processing system, CRAY T3E system, using MPI. The PC cluster system is configured with Pentium Ⅲ class PCs and fast ethernet. The CRAY T3E system is composed of a set of nodes each containing one Processing Element (PE), a memory subsystem and its distributed memory interconnect network. Parallel computing algorithms are implemented on element-wise processing parts including the calculation of stiffness matrix, element stresses and determination of material states, check of material failure and calculation of unbalanced loads. Parallel performance of the migrated program is evaluated through typical numerical examples.

• 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.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.2
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• pp.116-122
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• 2022

This study proposed a method of testing the stability when selecting gears to reduce the weight of a 3-DOF wrist mechanism for a pick-and-place 3-DOF parallel robot with an increased workspace by using an additional straight axis at its top. We performed SolidWorks^® modeling- and ANSYS^®-based structural analysis of a pinion gear, which is most vulnerable to the force from a 3-DOF wrist mechanism, to lighten the robot weight for performing various tasks. When the initial analysis results considerably differed from the theoretical values calculated in advance, we checked and identified the errors in the contact conditions or input values. Ultimately, it is believed that the methodology presented in this paper will help in mitigating errors during analysis and determine the accurate values for a lightweight 3-DOF wrist mechanism for a parallel robot with an expanded workspace.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.327-332
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• 2007

An engineering design problem involving Multi-Disciplinary Analysis(MDA) generally requires a large amounts of CPU time for the entire design process, and therefore Multiple Processing System (MPS) are essential to reduce the completion time. However, when applying conventional parallel processing techniques, all of the CAE S/W required for the MDA should be installed on all the servers making up NIPS because of characteristic of MDA and it would be a great expense in CAE S/W licenses. To solve this problem, we propose a Weight-based Multiqueue Load Balancing algorithm for a heterogeneous MPS where performance of servers and CAE S/W installed on each server are different of each other. To validate the performance, a computational experiments comparing the First Come First Serve algorithm and our proposed algorithm was accomplished.

• 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.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.23 no.5
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• pp.475-482
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• 2010

In this paper, an efficient two-level parallel domain decomposition algorithm is suggested to solve large-DOF structural problems. Each subdomain is composed of the coarse problem and local problem. In the coarse problem, displacements at coarse nodes are computed by the iterative method that does not need to assemble a stiffness matrix for the whole coarse problem. Then displacements at local nodes are computed by Multi-Frontal Sparse Solver. A parallel version of PCG(Preconditioned Conjugate Gradient Method) is developed to solve the coarse problem iteratively, which minimizes the data communication amount between processors to increase the possible problem DOF size while maintaining the computational efficiency. The test results show that the suggested algorithm provides scalability on computing performance and an efficient approach to solve large-DOF structural problems.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.9
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• pp.971-977
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• 2012

Redundant actuated parallel kinematic machines (PKMs) have been widely researched to increase stiffness of PKMs. This paper presents theoretical analyses on the stiffness of non-redundant and redundant actuated PKM. Stiffness of each mechanism is defined by summation of actuator and structural stiffness; the actuator stiffness is determined from displacements of actuators, and the structural stiffness is determined from deformations of links by external forces. Calculated actuator and structural stiffness of non-redundant PKM show same distribution in entire workspace. On the contrary, the actuator and the structural stiffness of a redundant PKM has very different distribution in the workspace; so, we conclude the structural stiffness of redundant PKM should be considered to design the redundant PKM. The results can be used to design and analyze non-redundant and redundant PKMs.