• Title/Summary/Keyword: boundary strength

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Changes of the hair's by straight permanent and magic straight permanent (스트레이트 퍼머 및 매직 스트레이트 퍼머에 의한 모발의 변화)

  • Lee, Jung-Eun;Hong, Jung-Min
    • Journal of the Korean Society of Fashion and Beauty
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    • v.1 no.1 s.1
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    • pp.133-142
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    • 2003
  • As you see, there's no difference of the hair's before and after Magic straight permanent on the example A's hair's thickness, the rate of the tense and the C's rate of the tense, but we can find that there are a lot of difference of the A's strength of the hair, the B's hair's thickness, the strength of the hair, the rate of the tense, the C's hair's thickness, and the strength of the hair on the before and after the Magic straight permanent. That is to say, there are more damage on the condition of normal hair than the one after the Magic straight permanent. On the change of the hair's physical character, before the permanent, the hair's schedule was regular and had the healthy head skin of clear mutual boundary But after the Magic straight permanent wave, the hair's schedule changed to unregural, had unclear mutual boundary of the head skin and the schedule was taken off so the cortex showed up and so on, every condition of the damage was very heavy. On the effect of the treatment, even though it gaves the worth condition of the hair, after the Magic straight permanent formally the change of the hair gives the beautiful straight.

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Effect of Intensity of Unconditional Stimulus on Reconsolidation of Contextual Fear Memory

  • Kwak, Chul-Jung;Choi, Jun-Hyeok;Bakes, Joseph T.;Lee, Kyung-Min;Kaang, Bong-Kiun
    • The Korean Journal of Physiology and Pharmacology
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    • v.16 no.5
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    • pp.293-296
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    • 2012
  • Memory reconsolidation is ubiquitous across species and various memory tasks. It is a dynamic process in which memory is modified and/or updated. In experimental conditions, memory reconsolidation is usually characterized by the fact that the consolidated memory is disrupted by a combination of memory reactivation and inhibition of protein synthesis. However, under some experimental conditions, the reactivated memory is not disrupted by inhibition of protein synthesis. This so called "boundary condition" of reconsolidation may be related to memory strength. In Pavlovian fear conditioning, the intensity of unconditional stimulus (US) determines the strength of the fear memory. In this study, we examined the effect of the intensity of US on the reconsolidation of contextual fear memory. Strong contextual fear memory, which is conditioned with strong US, is not disrupted by inhibition of protein synthesis after its reactivation; however, a weak fear memory is often disrupted. This suggests that a US of strong intensity can inhibit reconsolidation of contextual fear memory.

A Study on Fatigue strength by hardenability of Boron Addition Steel (보론 첨가강의 경화기구에 따른 기계적 성질에 관한 연구)

  • Lee, Jong-Hyung;Yoo, Duck-Sang;Park, Shin-Kyu
    • Journal of the Korean Society of Industry Convergence
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    • v.6 no.4
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    • pp.299-305
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    • 2003
  • This research is for the relationship with heat treatment cooling temprature and the characteristic of Mechanical properties of Boron-Addition-Steel, the main material and SM25C steel, the sub material, structure viewing fractography, hardness test, tensite test and are carried out after the manufacturing small-specimen treated with heat of $750^{\circ}C$, $850^{\circ}C$, $1050^{\circ}C$. The influence to the Mechanical properties accompanied by AISI51B20, Boron-Addition-steel shows the following result. 1. The influenc of heat treatment by the content of cabon-steel is dominant. Addition of boron result is Strengthening structure effectively by segregation and improving over all mechanical characters such as good. it results from the increase of temacity by the stability of inter granular with improvement of harden-ability. 2. Boron-Addition-Steel exist in the from of martensite structure accompanied by the ferrite precipitition centering around grain boundary, and is improved to Hv 200. 3. The height of harden-ability and fatigue stress the influence of heat results from crystal structure of martensite by difference of strength level in the structure of ferrite and doesn't have am effect on sensibility of temperature, and turns out to defend on production and growth of Matrix-structure-factor.

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An Extremely Low Temperature Properties of Wrought Aluminum Alloys (가공용 알루미늄 합금의 극저온 특성)

  • Jung, Chan-Hoi;Kim, Soon-Kook;Lee, Jun-Hee;Lee, Hae-Woo;Jang, Chang-Woo
    • Korean Journal of Materials Research
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    • v.17 no.4
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    • pp.192-197
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    • 2007
  • The effects of immersion time in the liquid nitrogen on the behavior of aluminum alloys used for the hydrogen storage tank of auto-mobile at cryogenic temperature were investigated. With increasing immersion time in the liquid nitrogen, the elongation of AI 5083 alloy at cryogenic temperature decreased because of non-uniform fracture of precipitates on the grain boundary, and the serration also occurred because of discontinuous slip due to rapid decreasing of the specific heat. The mechanical properties of AI 6061 alloy at cryogenic temperature were characterized by uniformed yield strength, tensile strength and elongation regardless of the immersion time in the liquid nitrogen. These mechanical properties of aluminum alloys at cryogenic temperature were interpreted by the strength of grain boundary and the slip deformation behavior.

Finite element model updating of in-filled RC frames with low strength concrete using ambient vibration test

  • Arslan, Mehmet Emin;Durmus, Ahmet
    • Earthquakes and Structures
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    • v.5 no.1
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    • pp.111-127
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    • 2013
  • This paper describes effects of infill walls on behavior of RC frame with low strength, including numerical modeling, modal testing and finite-element model updating. For this purpose full scaled, one bay and one story RC frame is produced and tested for plane and brick in-filled conditions. Ambient-vibration testis applied to identify dynamic characteristics under natural excitations. Enhanced Frequency Domain Decomposition and Stochastic Subspace Identification methods are used to obtain experimental dynamic characteristics. A numerical modal analysis is performed on the developed two-dimensional finite element model of the frames using SAP2000 software to provide numerical frequencies and mode shapes. Dynamic characteristics obtained by numerical and experimental are compared with each other and finite element model of the frames are updated by changing some uncertain modeling parameters such as material properties and boundary conditions to reduce the differences between the results. At the end of the study, maximum differences in the natural frequencies are reduced on average from 34% to 9% and a good agreement is found between numerical and experimental dynamic characteristics after finite-element model updating. In addition, it is seen material properties are more effective parameters in the finite element model updating of plane frame. However, for brick in-filled frame changes in boundary conditions determine the model updating process.

A Study on Low Velocity Impact Characteristics of DP 780 High Strength Steel Sheet with Thickness of 1.7 mm on the Free Boundary Condition Using Three-Dimensional Finite Element Analysis (3 차원 유한요소해석을 이용한 자유경계조건에서의 두께 1.7 mm DP780 고강도 강판의 저 속 충격 특성 분석)

  • Ahn, Dong-Gyu;Nam, Gyung-Heum;Seong, Dae-Yong;Yang, Dong-Yol;Lim, Ji-Ho
    • Journal of the Korean Society for Precision Engineering
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    • v.27 no.11
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    • pp.46-56
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    • 2010
  • The present research works investigated into the low velocity impact characteristics of DP 780 high strength steel sheet with 1.7 mm in thickness subjected to free boundary condition using three-dimensional finite element analysis. Finite element analysis was carried out via ABAQUS explicit code. Hyper-elastic model and the damping factor were introduced to improve an accuracy of the FE analysis. An appropriate FE model was obtained via the comparison of the results of the FE analyses and those of the impact tests. The influence of the impact energy and nose diameter of the impact head on the force-deflection curves, impact time, absorption characteristics of the impact energy, deformation behaviours, and stress-strain distributions was quantitatively examined using the results of FE analysis. The results of the FE analysis showed that the absorption rate of impact energy lies in the range of the 70.7-77.5 %. In addition, it was noted that the absorption rate of impact energy decreases when the impact energy increases and the nose diameter of the impact head decreases. The local deformation of the impacted region was rapidly increased when the impact energy was larger than 76.2 J and the nose diameter was 20 mm. A critical impact energy, which occur the instability of the DP780, was estimated using the relationship between the plastic strain and the impact energy. Finally, characteristics of the plastic energy dissipation and the strain energy density were discussed.

A Study on the Ultimate Strength According to the Boundary Condition of a Ship Plate under Thrust (압축하중을 받는 선체판의 경계조건에 따른 최종강도에 관한 연구)

  • 고재용;박주신;이돈출
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2002.11a
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    • pp.89-93
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    • 2002
  • One of the primary factors like plate structure in ship is redundancy structure that is comparable with ocean structure and frame structure. The more component material becomes buckling collapsed locally the less structure stiffness becomes accordingly. As a result, by increasing the load distribution of my other subsidiary structure continually component member collapses, therefore the structure could be in danger of collapse. So, in order to interpret this phenomenon precisely, the study on boundary condition of the ship's plate and post-buckling analysis must be considered In this study, the rectangular plate is compressed by the in-plane load Buckling & Ultimate strength characteristics are applied o be the elasto-plasticity large deformation by ansys code with F.E.M method On this basis, elasto-plasticity of the plain plate are investigated. This study proved elasto-plasticity behaviour of the ship's plate in accordance with boundary condition based on the series analysis in case of the compressive load operation

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Influences of porosity distributions and boundary conditions on mechanical bending response of functionally graded plates resting on Pasternak foundation

  • Guellil, Moustafa;Saidi, Hayat;Bourada, Fouad;Bousahla, Abdelmoumen Anis;Tounsi, Abdelouahed;Al-Zahrani, Mesfer Mohammad;Hussain, Muzamal;Mahmoud, S.R.
    • Steel and Composite Structures
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    • v.38 no.1
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    • pp.1-15
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    • 2021
  • In this paper, a higher order shear deformation theory for bending analysis of functionally graded plates resting on Pasternak foundation and under various boundary conditions is exposed. The proposed theory is based on the assumption that porosities can be produced within functionally graded plate which may lead to decline in strength of materials. In this research a novel distribution of porosity according to the thickness of FG plate are supposing. Governing equations of the present theory are derived by employing the virtual work principle, and the closed-form solutions of functionally graded plates have been obtained using Navier solution. Numerical results for deflections and stresses of several types of boundary conditions are presented. The exactitude of the present study is confirmed by comparing the obtained results with those available in the literature. The effects of porosity parameter, slenderness ratio, foundation parameters, power law index and boundary condition types on the deflections and stresses are presented.

Shear Strength of Retrofitted RC Squat Wall by Additional Boundary Element (단부 증타 보강된 RC 전단벽체의 전단강도)

  • Yi, You-Sun;Hong, Sung-Gul;Park, Young-Mi
    • Journal of the Korea Concrete Institute
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    • v.27 no.5
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    • pp.489-499
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    • 2015
  • This study suggested shear strength prediction model for retrofitted single-layered RC squat wall by providing column element as additional boundary element. This model revised existing shear strength prediction model of shear wall to consider detail and shear deformation capacity of column by assuming the length that concentrated shear deformation of the column is occurred. It was able to suggest additional compatibility condition related to shear strain of retrofitted of retrofitted shear wall at the ultimate state by using this length. Therefore, this study proposed a flow chart for predicting shear strength of the retrofitted shear wall considering this additional condition. Moreover, this study also proposed a method for predicting initial stiffness of the retrofitted shear wall by transforming the wall's resisting mechanism against to lateral load to a single diagonal strut mechanism. The proposed methods can predict shear strength and initial stiffness of not only the retrofitted shear wall of this study, also infilled RC shear wall in RC frame.

An Experimental Study on Fatigue Behavior in Welded SM45C Steel Rod (SM45C 환봉 용접재의 피로거동에 관한 실험적 연구)

  • Lee, Yong-Bok;Jung, Jae-Keun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.32 no.6
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    • pp.519-525
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    • 2008
  • For this study, SM45C steel rods using generally for power transmission shafts and machine components was selected and welded by butt-GMAW method. And then it was studied about estimation of fatigue strength and the region of infinite life by Haigh diagram using Goodman's equation. Fatigue strength in weld zone presents highly in order of the boundary between deposited metal zone and heat affected zone, deposited metal zone, heat affected zone. This result agrees with distribution of hardness in weld zone. Fatigue strength in base metal zone presents highly compared with weld zone in low cycles between $10^4$ cycles and $10^6$cycles, but it presents the lowest fatigue strength on the order of heat affected zone in the vicinity of $10^6$cycles. It is the result that the first high compressive residual stress distributed by drawing process of the steel rods is released and the base metal is softened by alternating stresses. The region of infinite life by Haigh diagram presents highly in order of the boundary between deposited metal zone and heat affected zone, deposited metal zone, heat affected zone. From this results, it is demanded that the stress for safety design of machine components using SM45C butt-welded steel rods must be selected in the region of the lowest infinite life of heat affected zone.