• Title/Summary/Keyword: Deformed shape

Search Result 442, Processing Time 0.025 seconds

Numerical Analysis of Shape Modification for the Composite Structures using SMA Strip Actuator (형상기억합금 작동기를 이용한 복합재료 구조물의 형상 변형 해석)

  • Roh Jin-Ho;Han Jae-Hung;Lee In
    • Proceedings of the Korean Society For Composite Materials Conference
    • /
    • 2004.10a
    • /
    • pp.278-281
    • /
    • 2004
  • In this paper, the thermomechanical responses of shape memory alloy (SMA) actuators and their applications as the shape adaptive structures combining SMA actuators produced in the form of strip with composite structures are investigated. The numerical algorithm of the 3-D SMA thermomechanical constitutive equations based on Lagoudas model is implemented to analyze the unique characteristics of SMA strip. Also, the incremental SMA constitutive equations are implemented in the user subroutine UMAT by using ABAQUS finite element program. The shape change of structure is caused by initially strained SMA strip bonded on the surface of the composite structure when thermally activated. Numerical results show that SMA strip actuator can generate enough recovery force to deform the composite structure and sustain the deformed shape subjected to large external load, simultaneously.

  • PDF

Frequency Domain Processing Techniques for Pulse Shape Modulated Ultra Wideband Systems

  • Gordillo, Alex Cartagena;Kohno, Ryuji
    • Journal of Communications and Networks
    • /
    • v.9 no.4
    • /
    • pp.482-489
    • /
    • 2007
  • In this paper, two frequency domain signal processing techniques for pulse shape modulation(PSM) ultra wideband(UWB) systems are presented. Firstly, orthogonal detection of UWB PSM Hermite pulses in frequency domain is addressed. It is important because time domain detection by correlation-based receivers is severely degraded by many sources of distortion. Pulse-shape, the information conveying signal characteristic, is deformed by AWGN and shape-destructive addition of multiple paths from the propagation channel. Additionally, because of the short nature of UWB pulses, timing mismatches and synchronism degrade the performance of PSM UWB communication systems. In this paper, frequency domain orthogonality of the Hermite pulses is exploited to propose an alternative detection method, which makes possible efficient detection of PSM in dense multipath channel environments. Secondly, a ranging method employing the Cepstrum algorithm is proposed. This method is partly processed in the frequency domain and can be implemented without additional hardware complexity in the terminal.

The Elasto-Plastic Finite Element Analysis of Ductile Fracture in Shape Rolling (형상압연시 연성파괴의 탄소성 유한요소해석)

  • 원영목;오규환
    • Transactions of Materials Processing
    • /
    • v.5 no.1
    • /
    • pp.72-80
    • /
    • 1996
  • During the shape rolling process the influence of reduction ration and taper of shape roller on deformation and limit of ductile fracture such as free surface cracks developing in the workpiece has been studied. The deformation behaviours were analyzed by the 3-dimensional elasto-pastic finite element method and the conditions of ductile fracture were determined from 3-dimensional elasto-plastic finite element method and modified Cockrogt-Latham criterion. The deformed geometry and prediction of ductile fracture by 3-dimensional elasto-plastic finite element method are compared with experimental results The calcuated results are in good agreements with experimental data. The analysis used in the study was found to be effective in predicting the shape rolling process.

  • PDF

The Sectional Analysis of Trunk-lid using the Equilibrium Approach and Three-Dimensional Shape Composition (평형해법을 이용한 트렁크 리드의 단면해석과 3차원 형상합성)

  • 정동원
    • Journal of Ocean Engineering and Technology
    • /
    • v.15 no.2
    • /
    • pp.66-71
    • /
    • 2001
  • A sectional analysis of trunk-lid carried out by using the equilibrium approach based on the force balance together with geometric relations and plasticity theory. In computing a force balance equation, it is required to define a geometric curve approximating the shape of sheet metal at any step of deformation from the interaction between the die and the deformed sheet. The trunk-lid panel material is assumed to possess normal anisotropy and to obey Hill's new yield criterion. Deformation of each section of trunk-lid panel is simulated and composed to get the three-dimensional shape by using CAD technique. It was shown that the three-dimensional shape composition of the two-dimensional analysis.

  • PDF

Otoplasty with High Density Polyethylene Implant(MEDPOR®) (잠복이에서 고밀도 폴리에틸렌 삽입물(MEDPOR®)을 이용한 귀성형술)

  • Lee, Keun-Cheol;Kwon, Yong-Seok;Heo, Jung;Moon, Ju-Bong;Kim, Seok-Kwun
    • Archives of Plastic Surgery
    • /
    • v.36 no.2
    • /
    • pp.167-173
    • /
    • 2009
  • Purpose: The key points of treatment of cryptotia are the elevation of invaginated ear helix and the correction of deformed cartilage. Prevention of stabilized cartilage contouring from returning to the previous state is also important. The authors carried otoplasty by modified Onizuka's method or Ohmori's method that conchal cartilage graft or high density polyethylene implant(MEDPOR$^{(R)}$) graft served as fixation after spreading posterior aspect of adhered antihelix and a splint for prevention of recurrence of cartilage deformities. The aim of this study is to reveal the availability of the high density polyethylene implant(MEDPOR$^{(R)}$) graft for the correction of cryptotia. Methods: We have repaired 17 cryptotic deformities using cartilage graft from cavum of concha(12 cases) or high density polyethylene implant(5 cases) for correction of deformed cartilage. We investigate the operative time, complications, and satisfaction of postoperative ear shape on both autogenous cartilage graft group and high density polyethylene implant graft group. Results: There was 1 case of reinvagination on autogenous cartilage graft group. Implant exposure was occurred on high density polyethylene implant graft group, as 1 case. These were statistically no differences between autogenous cartilage graft group and high density polyethylene implant graft group to the satisfaction of ear shape. Conclusion: High density polyethylene implant(MEDPOR$^{(R)}$) present an alternative to autogenous material as they allow of fibrovascular ingrowth, leading to stability of the implant and decreased infection rates. The correction of deformed cartilage by using the high density polyethylene implant(MEDPOR$^{(R)}$) is a good option for the treatment of cryptotia.

A Study on Make-up Expression of Horror Character in Horror Movie (공포영화에 나타난 공포 캐릭터의 분장표현 연구)

  • Kim, Yu-Kyoung;Cho, Ji-Na
    • Journal of Fashion Business
    • /
    • v.12 no.5
    • /
    • pp.77-93
    • /
    • 2008
  • The purpose of the study was to examine make-up expression elements of horror characters as an evil spirit, a vampire, a zombie, a monster and a psycho murderer through make-up, focused on horror movies of the United States after1960s. First, an evil spirit was expressed that the pupil grew dim without a focus and the skin was torn by going bad and rot completely. Also, it was expressed that its teeth was changed to pointed canine teeth as a wild beast and its pale and bloodless face showed blood vessels clearly. To express its bloodless and pale skin, air brush was swept into the skin over several times. Its canine tooth was made acryl powder into its shape and was harden to make its shape smooth. Also, it was colored to show people like the real thing. Second, a vampire was expressed by make-up elements as long nails, a sharp canine tooth, a pale skin with a blood vessel and dead eyes. Its rough skin and long nails were manufactured with latex foam, which was colored like the skin. Third, a monster image as a werewolf was expressed by make-up elements as fur, sharp teeth, changed nails and toenails, a rough skin and a face changed to a wolf. Rubber mask and rubber body suit were manufactured as a make-up of special character and so all its body was changed. Fourth, a psycho murderer and body-deformed man were expressed by make-up elements as a distorted mask, swelled-up and deformed skull and face form, terribly deformed body, discolored and hang down skin and teeth with an indeterminate form. Its body and face were manufactured by the foam latex technology according to make-up design as a make-up of special character.

The Study on the Mechanical Behavior of the Anastomosis with respect to the Thickness Variation of Elastic Foundation Using Simplified Suturing Model (단순봉합모델을 이용한 문합에서 탄성경계층의 두께 변화에 따른 기계역학적 거동에 관한 연구)

  • 이성욱;한근조;심재준;한동섭;김태형
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.21 no.8
    • /
    • pp.188-195
    • /
    • 2004
  • In this paper we analyzed the mechanical behavior with respect to the thickness variation of elastic foundation(fatty tissue) in end-to-end anastomosis. This study considered the preliminary deformed shape induced by suturing in the anastomosis of coronary artery and PTFE with different diameters using simplified suturing model and the fatty tissue surrounding heart and coronary artery for more accurate result using finite element method. Area compliance(CA) was used to analyze the final deformed shape of the anastomotic part with respect to the thickness variation of fatty tissue under mean blood pressure, 100mmHg(13.3㎪). And Equivalent and circumferential stresses in the anastomosis were also analyzed with respect to the change of initial diameter ratio( $R_1$) and fatty tissue thickness( $T_{F}$). The results obtained were as follows : 1 When the elastic foundation, assumed to be incompressive material, surrounded the grafts in anastomosis, the compliance mismatch of artery and PTFE was reduced by 47 -72%. 2. As the initial diameter ratio( $R_1$) became larger, the higher difference of compliance was induced in spite of elastic foundation surrounding grafts. 3. The maximum nondimensional circumferential stress is twice or three times as high as the maximum nondimensional equivalent stress in the anastomotic part.t.

The Study on Compliance Mismatch with respect to the Thickness Variation of Elastic Foundation in Anastomosis Using Simplified Suturing Model (단순봉합모델을 이용한 문합에서 탄성경계층의 두께 변화에 따른 컴플라이언스 부적합에 관한 연구)

  • 이성욱;심재준;한동섭;한근조;김태형
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2003.06a
    • /
    • pp.1302-1305
    • /
    • 2003
  • In this paper we analyzed the effect of compliance mismatch with respect to the thickness variation of elastic foundation(fatty tissue) in end-to-end anastomosis. This study considered the preliminary deformed shape induced by suturing in the anastomosis of coronary artery and PTFE with different diameters using simplified suturing model and the fatty tissue surrounding heart and coronary artery for more accurate result using finite element method. Area compliance(C$\sub$A/) was used to analyze the final deformed shape of the anastomotic part with respect to the thickness variation of fatty tissue under mean blood pressure, 100 mmHg(13.3kPa). The results obtained were as follows : 1. When the elastic foundation, assumed to be incompressive material, surrounded the grafts in anastomosis, the compliance mismatch of artery and PTFE was improved by 47∼72%. 2. As the initial diameter ratio(R$\sub$I/) became larger, the higher difference of compliance was induced in spite of elastic foundation surrounding grafts.

  • PDF

On the Stability of the Permanently Bent Mini-plate in Reconstructive Surgery (플레이트의 소성변형 과정이 재건술에서 플레이트 안정성에 미치는 영향)

  • Park, Si Myung;Lee, Deukhee;Noh, Gunwoo
    • Korean Journal of Computational Design and Engineering
    • /
    • v.21 no.3
    • /
    • pp.234-241
    • /
    • 2016
  • Conventional bent plate used in mandibular reconstruction surgery needs safety verification since its mechanical properties are changed due to the plastic deformation during the bending process. In this study we investigate stability of the plastically deformed plate and the plate with the same shape without plastic deformation through the finite element analysis(FEA). First we simulate the process of plate bending to fit the defect in patient. Then, the other plate is modelled to represent a customized plate with the same shape of the plastically deformed one, but without any residual stresses from plastic deformation. After binding these plates to the mandible, we conduct the masticatory simulation. Finally, we compare the resulting Von Mises stress of the customized plate and of the bent plate. The bent plate shows much higher stress than the customized one due to the residual stresses form the bending process. The study shows that plastic deformation in the plate may decrease the safety of the reconstruction surgery.

Experimental study on flexural strength of reinforced modular composite profiled beams

  • Ahn, Hyung-Joon;Ryu, Soo-Hyun
    • Steel and Composite Structures
    • /
    • v.8 no.4
    • /
    • pp.313-328
    • /
    • 2008
  • This study attempts to suggest bending reinforcement method by applying bending reinforcement to composite profile beam in which the concept of prefabrication is introduced. Profile use can be in place of framework and is effective in improvement of shear and bending strength and advantageous in long-term deflection. As a result of experiment, MPB-CB2 with improved module had higher strength and ductility than the previously published MPB-CB and MPB-LB. In case of bending reinforcement with deformed bar and built-up T-shape section based on MPB-CB2, the MPB-RB series reinforced with deformed bar were found to have higher initial stiffness, bending strength and ductility than the MPB-RT series. The less reinforcement effect of the MPB-RT series might be caused by poor concrete filling at the bottom of the built-up T-shape. In comparison between theoretical values and experimental values using minimum yield strength, the ratio between experimental value and theoretical value was shown to be 0.9 or higher except for MPB-RB16 and MPB-RT16 that have more reinforcement compared to the section, thus it is deemed that the reinforced modular composite profiled beam is highly applicable on the basis of minimum yield strength.