• Title/Summary/Keyword: Deformation

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Study on the Spinning Processes Combined with Shear and Shrinking Deformation (전단 및 교축변형이 조합된 복합스피닝 공정에 관한 연구)

  • 이항수;강정식
    • Transactions of Materials Processing
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    • v.8 no.5
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    • pp.507-519
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    • 1999
  • An approach using the energy method has veen proposed for the analysis of cone spinning having the complicated deformation modes mixed by shear and normal deformation. In the proposed method, the corresponding solution is found through optimization of the total energy dissipation with respect to the parameters assumed by the velocity field defined as the variation of the length in longitudinal direction. The sheet blank is divided into three layers to consider the bending effect and the energy dissipated by shear deformation is superposed to the energy consumption due to normal deformation related with the shrinking deformation is superposed to the energy consumption due to normal deformation related with the shrinking deformation of axi-symmetric sheet element for the evaluation of total deformation energy. In order to check the validity of the proposed method, the complex spinning for making the conical cup is analyzed and the computed results are compared with the experimental results. In comparison of the computed results with existing experimental results,, the good agreement is obtained for the variation of outer radius and the distribution of thickness, and it has thus been shown that the present approach is applicable to the analysis of complex spinning.

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On the Fillet Weld-Induced Deformation Control by Applying the Tensioning Method (장력법을 적용한 필릿용접변형 제어에 관한 연구)

  • Lee, Joo-Sung;Kim, Cheul-Ho
    • Journal of Welding and Joining
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    • v.27 no.4
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    • pp.38-43
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    • 2009
  • As it has been well appreciated, the weld-induced deformation control is one of the most important issues from view point of efficiency in ship production. The weld-induced deformation is more serious in the case of thin plate block than in the case of relatively thick plate block, since, for example, heat affect zone of thin plates is wider than that of thick plates for the same heat input. Among weld-induced deformation, buckling deformation due to shrinkage and residual stress in weld line direction is one of the most serious deformation type. This paper is concerned with the controling the buckling deformation of thin plate fillet weld by applying the tensioning method. Weld experiments have been carried out for specimens with varying the magnitude and direction of tension load. The results are graphically represented to show the effect of tensioning method upon reducing the weld-induced deformation. From the present findings, its has been seen that tensioning method is one of the useful ways to control the weld-induced deformation of fillet weld of thin plates.

3D Measurement of Skin Deformation for the Design of a Tight-fitting Torso Pattern (밀착형 셔츠 설계를 위한 피부변형의 3차원 측정)

  • Park, Hye-Jun;Wu, Yanjun;Hong, Kyung-Hi
    • Journal of the Korean Society of Clothing and Textiles
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    • v.34 no.11
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    • pp.1824-1835
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    • 2010
  • This study develops tight-fitting torso patterns for performance garments by taking into account the skin deformation generated directly from a 3D scan during arm movements. The skin deformation caused during the arm movements was scanned after scanning the skin surface stamped with a circle. To create a torso pattern in response to skin deformation, the ratio and direction of the skin deformation were first measured and analyzed so that the 3D human body could be segmented. After translating, the 3D skin surface was segmented into 2D flat patterns, designing nude patterns and reducing them as well as tight-fitting shirts: the skin deformation segment shirts were made in response to the skin deformation. The features of the fabric deformation and the garment pressure were analyzed and evaluated. In comparison with a clothing construction segment shirt, the diameter of the skin deformation segment shirt was smaller as well the ratios of extension and reduction was less. The garment pressure of the skin deformation segment shirt was higher. The skin deformation segment shirt fitted more tightly compared to a clothing construction segment shirt as it covered the body more thoroughly and was as comfortable as the other shirts with less fabric deformation made as the body moved.

A Study on the Bend Deformation Cause Analysis of CAE Applied Wire to Board Connectors (압접 커넥터 CAE 적용 휨 변형 원인 분석에 관한 연구)

  • Jeon, Yong-Jun;Shin, Kwang-Ho;Heo, Young-Moo
    • Design & Manufacturing
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    • v.10 no.1
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    • pp.19-25
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    • 2016
  • Connectors are very important components that transmit electric signals to different parts. It must maintain intensity of the connector to prevent defects from impact and maintain contact to transmit electric signals. Most of the external parts of the connector, which act as the main framework, are formed by injection molding. However, bend deformation occurs for injection molded products due to the residual stress left inside the product after product molding. When the bend deformation is large, it does not come into complete contact when being assembled with other parts, which leads to connector contact intensity not being properly maintained. In result, the main role of the connector, which is to transmit electric signals, cannot be performed. In order to address this problem, this study conducted bend deformation cause analysis through bend deformation analysis to predict and prevent bend deformation of housings and wafers, which are injection molded products of pressure welded connectors that are normally applied in compact mobile and display products. Bend deformation analysis was carried out by checking the charging time, pressure distribution and temperature distribution through wire to board connector wafer and housing injection molding analysis. Based on the results of the bend deformation analysis results, the cause of the bend deformation was analyzed through deformation resulting from disproportional cooling, deformation resulting from disproportional contraction, and deformation resulting from ingredient orientation. In result, it was judged that the effects for bend deformation were biggest due to disproportional contraction for both the pressure welded connector wafer and housing.

Effect of Deformation Induced Martensite Transformation on the Mechanical Properties in Austenitic Stainless Steel with High Mn (고 Mn 오스테나이트계 스테인리스강의 기계적성질에 미치는 가공유기 마르텐사이트 변태의 영향)

  • Hur, T.Y.;Han, H.S.;Lee, S.H.;Kang, C.Y.
    • Journal of Power System Engineering
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    • v.16 no.3
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    • pp.51-56
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    • 2012
  • The effect of deformation induced martensite transformation on the mechanical properties in austenitic stainless steel with high Mn was studied. ${\alpha}$'-martensite was formed by deformation in austenitic stainless steel with high Mn. Deformation induced ${\alpha}$'-martensite was formed with surface relief by cold rolling. With the increase of deformation degree, volume fraction of deformation induced martensite was increased rapidly in early stage of deformation and then, increased slowly. With the increase of deformation degree, hardness and tensile strength were rapidly increased with linear relations, while elongation was rapidly decreased and then slowly decreased. Hardness, tensile strengths and elongation were influenced strongly by deformation induced martensite.

Deformation Monitoring and Prediction Technique of Existing Subway Tunnel: A Case Study of Guangzhou Subway in China

  • Qiu, Dongwei;Huang, He;Song, Dong-Seob
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.30 no.6_2
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    • pp.623-629
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    • 2012
  • During the construction of crossing engineering one of the important measures to ensure the safety of subway operation is the implementation of deformation surveying to the existing subway tunnel. Guangzhou new subway line 2 engineering which crosses the existing tunnel is taken as the background. How to achieve intelligent and automatic deformation surveying forecast during the subway tunnel construction process is studied. Because large amount of surveying data exists in the subway construction, deformation analysis is difficult and prediction has low accuracy, a subway intelligent deformation prediction model based on the PBIL and support vector machine is proposed. The PBIL algorithm is used to optimize the exact key parameters combination of support vector machine though probability analysis and thereby the predictive ability of the model deformation is greatly improved. Through applications on the Guangzhou subway across deformation surveying deformation engineering the prediction method's predictive ability has high accuracy and the method has high practicality. It can support effective solution to the implementation of the comprehensive and accurate surveying and early warning under subway operation conditions with the environmental interference and complex deformation.

Experiments for measuring parts deformation and misalignments using a visual sensor (시각센서를 이용한 부품변형 및 상대오차 측정 실험)

  • 김진영;조형석;김성권
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.1395-1398
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    • 1997
  • Flexible parts comparing with rigid parts can be deformed by contact force during assembly. for successful assembly, information about their deformation as well as possible misalignment between mating parts is essential. Howecer, because of the complex relationship between parts deformation and reaction forces, it is difficult to acquire all required information from the reaction forces alone. In this paper, we measure parts deformation and misalignments by using the visual sensing system presented for flexible parts assembly. Experimental results show that the system can be effectively used for detecting parts deformation and misalignments between mating parts.

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Deformation Characteristics and Determination of Deformation Modulus of Rocks around the Lower Gangway during Coal Mining Operation (석탄층 하반갱도 주위암반의 변형특성 및 변형계수 결정연구)

  • 이현주
    • Tunnel and Underground Space
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    • v.2 no.2
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    • pp.237-250
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    • 1992
  • The cavities formed by the excavation of coal seam cause unstable within rock body, leading to large displacement around adjacent roadway. This displacement brings the closure of roadway and deformation of support. Therefore, it is necessary to understand and predict the deformation characteristics of roadway while coal seam is under excavation. In this study, the observed displacements are compared with the calculated ones through the analysis using Linear Boundary Element Mothod under the elastostatic conditions, in order to determine the virgin stress state and deformation modulus which affect the deformation characteristices.

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The Effect of Plastic Strain on the Superplastic Deformation Behavior (초소성변형특성에 미치는 소성변형랴의 영향)

  • 권용남;장영원
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1997.03a
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    • pp.291-293
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    • 1997
  • The effect of strain accumulation on the superplastic deformation behavior has been investigated through a series of load relaxation tests. The experimental results were analyzed using the recently proposed inelastic constitutive theory. The superplastic deformation of fine grained materials is confirmed to consist of grain boundary sliding and accommodating grain matrix deformation. However the flow behavior is changed with the plastic strain. It is believed that the microstructural changes such as grain growth and cavitation affect the superplastic deformation behaviors.

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A study on the effect of residual stress on welding deformations in thin plate structures (판구조물의 용접 변형에 미치는 잔류응력의 영향에 관한 연구)

  • 서승일
    • Proceedings of the KWS Conference
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    • 2004.05a
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    • pp.217-219
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    • 2004
  • It has been known that out-of-plane deformation in thin plate structure is caused by the angular deformation of welded joint. However, experimental results show that conventional theory based on angular deformation is not appropriate for prediction of out-of-plane deformation in thin plate structure. In this study, large deformation plate theory is introduced to clarify the effect of residual stress on out-of-plane deformation. The results by the proposed method show good agreement with the experimental results.

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