• Title/Summary/Keyword: deforming

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A single slotted morphing flap based on SMA technology

  • Ameduri, Salvatore;Concilio, Antonio;Pecora, Rosario;Karagiannis, Dimitrios
    • Smart Structures and Systems
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    • v.17 no.5
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    • pp.819-835
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    • 2016
  • In this paper, the activities carried out within the EU funded Clean Sky Joint Technology Initiative (JTI GRA) Project and aimed at developing a morphing flap, are illustrated. The reference device is a regional aircraft single slotted flap, enhanced with deforming capabilities to obtain improved hyper-lift performance. The design started with the identification of the internal architecture, intended to allow camber variations. A concentrated-hinge architecture was selected, for its ability to fit different curvatures and for the possibility of easily realizing an "armadillo-like" configuration, then avoiding the use of a complicate deformable skin. The flap layout is made of segmented ribs, elastically hinged each other and span-wise connected by conventional spars. Relative rotations of the rib elements are forced by SMA structural actuators, i.e., cooperating in the external loads absorption. Super-elastic SMA are used to make up recovery elastic elements, necessary to regain the original shape after activation. These further elements in turn contribute to the overall flap rigidity. After assessing the hinge number and the size of the SMA active and passive elements, the advanced design phase was dealt with. It was aimed at solving manufacturing issues and producing the executive drawings. The realized demonstrator was finally tested in lab conditions to prove its functionality in terms of whether target shape actuation or attained shape preservation under loads. On the basis of the numerical results and the experimental outcomes, precious hints were obtained for further developments of the concept.

Geomechanical and thermal reservoir simulation during steam flooding

  • Taghizadeh, Roohollah;Goshtasbi, Kamran;Manshad, Abbas Khaksar;Ahangari, Kaveh
    • Structural Engineering and Mechanics
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    • v.66 no.4
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    • pp.505-513
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    • 2018
  • Steam flooding is widely used in heavy oil reservoir with coupling effects among the formation temperature change, fluid flow and solid deformation. The effective stress, porosity and permeability in this process can be affected by the multi-physical coupling of thermal, hydraulic and mechanical processes (THM), resulting in a complex interaction of geomechanical effects and multiphase flow in the porous media. Quantification of the state of deformation and stress in the reservoir is therefore essential for the correct prediction of reservoir efficiency and productivity. This paper presents a coupled fluid flow, thermal and geomechanical model employing a program (MATLAB interface code), which was developed to couple conventional reservoir (ECLIPSE) and geomechanical (ABAQUS) simulators for coupled THM processes in multiphase reservoir modeling. In each simulation cycle, time dependent reservoir pressure and temperature fields obtained from three dimensional compositional reservoir models were transferred into finite element reservoir geomechanical models in ABAQUS as multi-phase flow in deforming reservoirs cannot be performed within ABAQUS and new porosity and permeability are obtained using volumetric strains for the next analysis step. Finally, the proposed approach is illustrated on a complex coupled problem related to steam flooding in an oil reservoir. The reservoir coupled study showed that permeability and porosity increase during the injection scenario and increasing rate around injection wells exceed those of other similar comparable cases. Also, during injection, the uplift occurred very fast just above the injection wells resulting in plastic deformation.

A New Method of Liquefaction Evaluation Based on Disturbed State Concept (교란상태개념에 기초한 새로운 액상화 평가 방법)

  • 박인준;김수일
    • Journal of the Earthquake Engineering Society of Korea
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    • v.2 no.2
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    • pp.45-55
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    • 1998
  • Although a number of methods have been proposed to predict the liquefaction potential, few methods have been developed by using the characteristic of material's microstructure. In this research, fundamental procedure is proposed for the assessment of liquefaction potential in saturated soils based on the Disturbed Sate Concept(DSC) model which can provide a unified constitutive model for the characterization of entire stress-strain behavior under cyclic loading. From this concept, the value of disturbance at threshold state (Critical Disturbance, $D_C$) in the deforming microstructure provides the basis for initial liquefaction. This method is verified with respect to data from Cyclic Truly Triaxial test for saturated Ottawa sand. Also, the relationship between liquefaction and initial confinig stress is defined using definition of $D_C$. It is believed that the new procedure for identifying liquefaction based on the DSC model can capture the behavior of liquefation, and as a result, it is shown to be on improvement over the available empirical procedures.

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Lip Shape Synthesis of the Korean Syllable for Human Interface (휴먼인터페이스를 위한 한글음절의 입모양합성)

  • 이용동;최창석;최갑석
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.4
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    • pp.614-623
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    • 1994
  • Synthesizing speech and facial images is necessary for human interface that man and machine converse naturally as human do. The target of this paper is synthesizing the facial images. In synthesis of the facial images a three-dimensional (3-D) shape model of the face is used for realizating the facial expression variations and the lip shape variations. The various facial expressions and lip shapes harmonized with the syllables are synthesized by deforming the three-dimensional model on the basis of the facial muscular actions. Combications with the consonants and the vowels make 14.364 syllables. The vowels dominate most lip shapes but the consonants do a part of them. For determining the lip shapes, this paper investigates all the syllables and classifies the lip shapes pattern according to the vowels and the consonants. As the results, the lip shapes are classified into 8 patterns for the vowels and 2patterns for the consonants. In advance, the paper determines the synthesis rules for the classified lip shape patterns. This method permits us to obtain the natural facial image with the various facial expressions and lip shape patterns.

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Symmetric Shape Deformation Considering Facial Features and Attractiveness Improvement (얼굴 특징을 고려한 대칭적인 형상 변형과 호감도 향상)

  • Kim, Jeong-Sik;Shin, Il-Kyu;Choi, Soo-Mi
    • Journal of the Korea Computer Graphics Society
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    • v.16 no.2
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    • pp.29-37
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    • 2010
  • In this paper, we present a novel deformation method for alleviating the asymmetry of a scanned 3D face considering facial features. To handle detailed areas of the face, we developed a new local 3D shape descriptor based on facial features and surface curvatures. Our shape descriptor can improve the accuracy when deforming a 3D face toward a symmetric configuration, because it provides accurate point pairing with respect to the plane of symmetry. In addition, we use point-based representation over all stages of symmetrization, which makes it much easier to support discrete processes. Finally, we performed a statistical analysis to assess subjects' preference for the symmetrized faces by our approach.

Analysis of Mateiral Flow in Metal Forming Processes by Using Computer Simulation and Experiment with Model Material (소성가공시 재료유동에 대한 수치해석 및 모델실험)

  • 김헌영;김동원
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.2
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    • pp.285-299
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    • 1993
  • The objective of the present study is to analyze material flow in the metal forming processes by using computer simulation and experiment with model material, plasticine. A UBET program is developed to analyze the bulk flow behaviour of various metal forming problems. The elemental strain-hardening effect is considered in an incremental manner and the element system is automatically regenerated at every deforming step in the program. The material flow behavior in closed-die forging process with rib-web type cavity are analyzed by UBET and elastic-plastic finite element method, and verified by experiments with plasticine. There were good agreements between simulation and experiment. The effect of corner rounding on material flow behavior is investigated in the analysis of backward extrusion with square die. Flat punch indentation process is simulated by UBET, and the results are compared with that of elastic-plastic finite element method.

Aesthetics of Japanese Avant-garde Fashion -Focusing on Planarization of the Body- (일본 아방가르드 패션의 미학 -몸의 평면화를 중심으로-)

  • Yim, Eun-Hyuk
    • Journal of the Korean Society of Costume
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    • v.57 no.1 s.110
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    • pp.50-65
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    • 2007
  • Clothes and human body are inseparably related. Aesthetic consciousness of the body determines the form of clothing, reflecting the time and culture as well as the individual and society. Clothes can even reorganize the meaning of the body, while transcending their instrumental functions of protecting, expanding and deforming the body. Using 'body' to analyze the clothing form, my study develops a framework by which to classify the planarization of the body in Japanese avant-garde fashion. In order to inquire the formative style and aesthetic values expressed in Japanese avant-garde fashion, my study examines subjects from the discourse on the body to the fashion collections of the 20th and 21st century. The results of the study are as follows. Japanese avant-garde fashion focuses on a planarization of the body which questions the three dimensional construction of the body in more conventional clothing system. Un-structured, variable space posited between the body and clothes, participation of the wearer, attention to recent technology and material, and absence of gender identification characterizes the planarization of the body in Japanese avant-garde fashion. The absence of body in fashion stresses a will-to-form rather than mere bodily proportion and structure, which explores trans-extensity that goes beyond the boundary of the body Ultimately, planarization of the body betrays the correspondence between signifiant and signifie in sartorial convention. Aesthetic ideal of the body is visualized in the form of a dress. Some clothes prioritize the body, particularly the feminine bodily curves, while others focus on the clothing itself as abstract and sculptural forms. Fashion continues to explore forms and images that transcend the traditional representations of the clothed body. As a type of intimate architecture, fashion always mediates the dialogue between clothes and body, or fashion and figure. My study suggests a framework to analyze bodily representation in Japanese avant-garde fashion, focusing on the relationship between the clothes and body.

Analysis of Hydrostatic Bulging of a Rectangular Diaphragm by Using the Energy Method (에너지법에 의한 직사각형 격막의 정수압벌징 해석)

  • 양동열;이항수
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.4
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    • pp.684-695
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    • 1992
  • The present study is concerned with the analysis of three-dimensional sheet metal forming process by the upper-bound method. For the analysis a systematic approach is necessary for the expression of geometric configuration of the deforming workpiece. In the present paper geometric configuration is constructed by three unit surfaces which are defined by sweeping the vertical section curves and boundary curve. The principal components of strain increment during the process is calculated directly from the change of geometric configuration for an arbitrary triangular element. The corresponding solution is found through optimization of the total energy consumption with respect to some parameters assumed in the velocity field and geometric profile. In order to verify the effectiveness of the present method, hydrostatic bulging of a rectangular disphragm is analyzed and the computation by the present method for the geometric shape renders the good result. From the comparison of the present results with the existing experimental results and elastic-plastic finite element solutions, good agreements have been obtained for the pressure curves, polar membrane strains and pressure distributions. The present method can thus be further applied to the analysis of other three-dimensional sheet metal forming processes.

Development of a double-sliding friction damper (DSFD)

  • Shen, Shaodong;Pan, Peng;Sun, Jiangbo;Gong, Runhua;Wang, Haishen;Li, Wei
    • Smart Structures and Systems
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    • v.20 no.2
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    • pp.151-162
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    • 2017
  • In practical engineering, the friction damper is a widely used energy dissipation device because of its large deformation capacity, stable energy dissipation capability, and cost effectiveness. While based on conventional friction dampers, the double-sliding friction damper (DSFD) being proposed is different in that it features two sliding friction forces, i.e., small and large sliding friction forces, rather than a single-sliding friction force of ordinary friction dampers. The DSFD starts to deform when the force sustained exceeds the small-sliding friction force, and stops deforming when the deformation reaches a certain value. If the force sustained exceeds the large sliding friction force, it continues to deform. Such a double-sliding behavior is expected to endow structures equipped with the DSFD better performance in both small and large earthquakes. The configuration and working mechanism of the DSFD is described and analyzed. Quasi-static loading tests and finite element analyses were conducted to investigate its hysteretic behavior. Finally, time history analysis of the single-degree-of-freedom (SDOF) and multi-degree-of-freedom (MDOF) systems were performed to investigate the seismic performance of DSFD-equipped structures. For the purpose of comparison, tests on systems equipped with conventional friction dampers were also performed. The proposed DSFD can be realized perfectly, and the DSFD-equipped structures provide better performances than those equipped with conventional friction dampers in terms of interstory drift and floor acceleration. In particular, for the MDOF system, the DSFD helps the structural system to have a uniform distributed interstory drift.

A study of the influences of Malevich's "Victory Over the Sun" on contemporary fashion design - Focused on Martin Margiela - (말레비치의 "Victory Over the Sun"이 현대 패션디자인에 미친 영향 - Martin Margiela를 중심으로 -)

  • Park, Yoon Jeong
    • The Research Journal of the Costume Culture
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    • v.24 no.6
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    • pp.839-853
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    • 2016
  • This study proposes that Malevich's 1913 performance "Victory Over the Sun" was not just Cubo Futurism, but that it produced Suprematism in the early 20th century. "Victory Over the Sun" did away with traditional set and costume design and a call to the Russian avant garde. Therefore, this study analyzes the characteristics of set and the costume design in "Victory Over the Sun", and considers how it impacted twenty-first century fashion designers like Margiela. The results of the study are as follows: first, Margiela reinterpreted the characteristics of the costumes featured on "Victory Over the Sun" from a cubist perspective and represented geometric spatial structures and mechanical human images through changes in methods and materials. second, he designed costumes by applying to the set and costumes expressed black & white images on "Victory Over the Sun". and third, Margiela reinterpreted the warrior image using geometric forms and colors in a creative way. Contemporary fashion designers, including Margiela, express their artistic creativity through various representational and materials choices. They want to convey their subjective personality and emotional sensibility to the public by mixing and deforming existing arts like painting, sculpture, and crafts to create new images. Thus, the creative intentions of the latest fashion designers have expanded art of costume design, exemplifying the process by which art is evolves and is made new.