• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10a
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• pp.229-232
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• 2003

In the roll forming process, a sheet or strip of metal is continuously and progressively formed into a desired cross-sectional profile by feeding it through a series of forming roll. Accordingly, it is important to maintain the material properties of the initial sheet and deform uniformly during the roll forming. The roll forming process was estimated in consideration of some factors such as material properties, strip thickness, roll diameter, roll velocity, and the deformation of the material that influence the forming length. The hydroforming technology has been recognized as a new technique in manufacturing industry, especially in automotive industry. The formed pipe in used in hydroforming process is manufactured by the roll forming. The formability during hydroforming is very sensitive to the state of pipes which are made by roll forming. Particularly the amount of hardening during roll forming affects the formability. Therefore, it is necessary to design the optimum roll flower to reduce the local hardening. In this paper, optimum roll flower which has uniform strain distribution through sheet width was obtained by comparing strain distribution in various roll flower. Finite element analysis(FEA) is performed to estimate the strain distribution related to hardening by roll forming. A numerical analysis is carried out by SHAPE-RF.

• Journal of Korean Association for Spatial Structures
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• v.17 no.4
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• pp.149-157
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• 2017

An innovative analysis method is proposed in this paper for the determination of ultimate resistance of prestressed concrete beams. The proposed method can be applied to simply supported or continuous beams in a unified manner whether structure and external loads are symmetric or not. Through the iterative nonlinear strain compatibility solutions, this method can also be applied to the non-prismatic section/un-symmetrical composite structures under moving load. The conventional studies have used the failure criteria when the strain of concrete reaches 0.003. However compared with bonded case, the value of strain in the reinforcement is much smaller than bonded case, thus, unbonded prestressed cases show compressive failure mode. It is shown that the proposed method gives acceptable results within 5% error compared with the prior experimental results. It can be shown that the proposed method can reach the solution much faster than typical three-dimensional finite element analysis for the same problem. This method is applicable to the existing unbonded prestressed members where deterioration has occurred leading to the reduced ultimate resistance or safety. In all, the proposed procedure can be applied to the design and analysis of newly constructed structures, as well as the risk assessment of rehabilitated structures.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.1
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• pp.10-15
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• 2016

This research was conducted structural analysis in order to analyze the impact of the gear in Urea pump when the water is frozen. Subject of study, gear was designed nine models, this gear is a spur gear, located in pump. Contact conditions and rotation conditions were set the gear's condition of restriction. Given 136 MPa pressure to external gear by water was set to the applied stress. The performing result of structural analysis, maximum stress and strain are appeared between two gears. At the same diameter, strain and stress are decreased gradually thicker. Because of the little part in crevice between gears, this parts of gears could be obtained conclusion to be generated maximum stress and strain.

• Journal of Veterinary Science
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• v.22 no.6
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• pp.66.1-66.9
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• 2021

Background: Maedi/Visna virus (MVV) is a contagious viral pathogen that causes considerable economic losses to the sheep industry worldwide. Objectives: In China, MVV has been detected in several regions, but its molecular characteristics and genetic variations were not thoroughly investigated. Methods: Therefore, in this study, we conducted next-generation sequencing on an MVV strain obtained from northwest China to reveal its genetic evolution via phylogenetic analysis. Results: A MVV strain obtained from Inner Mongolia (NM) of China was identified. Sequence analysis indicated that its whole-genome length is 9193 bp. Homology comparison of nucleotides between the NM strain and reference strains showed that the sequence homology of gag and env were 77.1%-86.8% and 67.7%-75.5%, respectively. Phylogenetic analysis revealed that the NM strain was closely related to the reference strains isolated from America, which belong to the A2 type. Notably, there were 5 amino acid insertions in variable region 4 and a highly variable motif at the C-terminal of the surface glycoprotein (SU5). Conclusions: The present study is the first to show the whole-genome sequence of an MVV obtained from China. The detailed analyses provide essential information for understanding the genetic characteristics of MVV, and the results enrich the MVV library.

• Journal of the Korean Society for Precision Engineering
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• v.11 no.5
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• pp.161-170
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• 1994

This paper presents the performance and problems in analysis method and testing system of Electronic Speckle Pattern Interfermetry(ESPI) method, in measuring two-dimensional in- plane displacement. The analysis result of measurement by ESPI is quite comparable to that of measurement by strain gauge method. This implieds that the method of ESPI is a very effective tool in non-contact two-dimensional in-plane strain analysis. But there is a controversial point, measurement error. This error is discussed to be affected not by ESPI method itself, but by its analysis scheme of the interference fringe, where the first-order interpolation has been applied to the points of strain measured. Further development of advanced first-order interpolation method is being undertaken for the more precise in-plane strain measurement.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.03a
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• pp.153-158
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• 1999

In the design and analysis of soil nailed slope, interaction between soil and nail is one of important problems. In the present analysis approaches for the interactions have developed a elastic analysis approach or a plastic analysis approach. However these approaches are not able to estimate the general interaction between soil and nail. In this study the general interaction between soil and nail using the strain wedge model is proposed. Also results of comparison between the proposed method and full scale test results by Gassler(1976) and large scale experimental results at Oxford University are shown in good agreements.

• 한국방재학회:학술대회논문집
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• 2007.02a
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• pp.109-112
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• 2007

To determine design or remaining life of flexible pavement, tensile strain at the bottom of asphalt concrete course and vertical strain on top of subgrade should be estimated. Various computer programs can be used for determining the strain at the critical position in pavement. However, these are conducted under the assumptions of full bonded or unbound state of layer interface conditions. This study compares the output of finite element analysis and multi-layer elastic analysis as vertical load was applied to the surface of flexible pavement. It is noted that the pavement performance is significantly affected depending upon the interface conditions.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.9
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• pp.126-134
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• 2008

Kendo is one of the popular sports in modem life. Head, wrist and thrust attack are the fast skill to get a score on a match. Human muscle skeletal model was developed for biomechanical study. The human model was consists with 19 bone-skeleton and 122 muscles. Muscle number of upper limb, trunk and lower limb part are 28, 60, 34 respectively. Bone was modeled with 3D beam element and muscle was modeled with spar element. For upper limb muscle modelling, rectus abdominis, trapezius, deltoideus, biceps brachii, triceps brachii muscle and other main muscles were considered. Lower limb muscle was modeled with gastrocenemius, gluteus maximus, gluteus medius and related muscles. The biomechanical stress and strain analysis of human muscle was conducted by proposed human bone-muscle finite element analysis model under head, wrist and thrust attack for kendo training.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.6
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• pp.2435-2440
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• 2012

In this paper, Solidworks was used to do a conceptional design of an box of an electric saver in order to manufacture an electric saver having a different performance and model. Based on this, analysis was made considering weight concentrated on an box. 3-dimensional finite element analysis code, ANSYS was applied to obtain stress, strain and deformation in order to secure durability and these data was reflected to a detailed drawing.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.04a
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• pp.137-144
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• 2003

Since quasi-brittle material like concrete shows strain localization behavior accompanied by strain softening, a numerical drawback such as mesh sensitivity is appeared in the finite element analysis. In this study, a homogenized crack model which overcomes the drawback and considers rate discontinuity in the constitutive equation is proposed for modeling of cracking in concrete and its propagation in strain softening regime. Then, a series of finite element analysis of the concrete under various loading conditions has been performed. From comparison of analysis results with experimental data, it is shown that failure behavior due to localized cracking of concrete under both compressive loading condition and tensile loading condition is well predicted by the homogenized crack model.