• Title/Summary/Keyword: Stress softening

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폐암(肺癌)의 한의치료(韓醫治療)에 관(關)한 문헌적(文獻的) 고찰(考察)

  • Park, Jeong-Hui;Kim, Byeong-Tak;Kim, Seong-Hun
    • The Journal of Korean Medicine
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    • v.16 no.1 s.29
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    • pp.71-95
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    • 1995
  • To be helpful to the treatment of pulmonary cancer with oriental medicine, we got clinical reports together and analyzed the data. The results were obtained as follows: 1. The treating methods could be summarized as three methods that were reinforcing vital energy, eliminating harmful Qi, and reinforcing vital energy with eliminating harmful Qi. The methods of reinforcing vital energy were supplementing Qi & Yin, increasing pahological heat & reinforcing kidney, augmenting Qi & blood, supplementing vital energy and strengthening fundermental energy, reinforcing spleen and increasing Qi, lubricate Yin and lung, and the other methods of eliminating harmful Qi were transforming pathological fluid and softening, clarifying heat and eliminating poison, dipersing lung and softening, toxicding and softening, guiding Qi and activating blood, clarifying heat and dispersing lung, guiding Qi and counteracting stress etc., and the methods of supplementing vital energy with eliminating poison were reinforcing spleen and transforming pathological fluid, increasing Qi and activating blood, supplementing Yin and clarifying heat, reinforcing spleen and dry the dampness, lubricating lung and transforming patholigical fluid and supplementing Qi and activating blood. 2. The oriental prescriptions used for pulmonary cancer were Chunkeum-Weekyungtang & Sohamhwingtang, Jinhayookgunjatang, Hyulboochukeotang, Bokbangkyogonamtang was reported to be effective in the treatment of metastasis. 3. Bokbangshinjingtang and haewool were applied for the complications of pulmonary cancer, Soshihotang for fever, hangamryung for tumor pain. Prunus ansu Komarov, Eriobotrya japonica Lirdley, Pyrrosiae lingua Farwel, Steomon japonica Miguel, Maximowiczia chinensis Ruprecht var, Morus bombycis Koidzumi for cough, Panax Pseudo-ginseng Wall. var, Bletilla striata Reichenbach f., Acacia catechu(兒茶) for hemoptysis, Lonicerae flos, Aspongopus chinensis(九香蟲) for chest pain, Cypsum Fibrosum, Gazella gutturosa, Scutellaria baicalensis Georgi, Gypsophila oldhamiana Miquel for fever, Lepidii semen descurainiae semen, Belamcanda chinensis D.C, Gnaphalium affine(佛耳草) for asthma. 4. For the reduction of side effect by chemotherapy and radiotherapy it was known that supplementing Qi was used chiefly for side effect of chemotherapy and augmenting Yin applied to side effect of radiotherapy. 5. The oriental presciptions were suggested for the side effect by chemotherapy and radiotherapy ; Sammaekaek(參麥液), Whaebokwontang(化瘀復元湯), Hwangjungomitang(黃精五味湯), Yukmijihwangtang(六味地黃湯), Hyangsayukgunjatang(香砂六君子湯), Samlyeekulsan for side effect by chemotherapy while Geumgweisingiwhan, Hwanglyentang(黃連湯), Hwanglyenhaedoktang(黃連解毒湯), Yangyeunchungpeitang(養陰淸肺湯), Idongtang(二冬湯), Jayeunkanghwatang(滋陰降火湯) for side effect by radiotherapy.

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Elasto-plastic Analysis and In-situ Measurement on Rock Behaviors with Stepwise Excavation of the Steep Soft Seam at a Great Depth (심부 급경사 연약층의 채굴 진행에 따른 주변 암반 거동의 탄소성 해석 및 현장계측)

  • 정소걸;신중호
    • Tunnel and Underground Space
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    • v.14 no.4
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    • pp.295-303
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    • 2004
  • For the deep underground excavation site with the geological complexity of soft seam and hard rock, the numerical analysis and in-situ measurement on the behaviors of roadway and surrounding rock according to stepwise excavation of the steep soft seam are carried out. The strata behavior is modeled using elasto-plastic FEM considering the empirical failure criteria of Hoek & Brown and the strain-softening model. Hydraulic pressure capsule, MPBX and tape extensometer are installed around the roadway for the in-situ measurement of rock stress and deformation. Despite the complexity of geology and excavation procedure, the elasto-plastic analysis considering the empirical failure criteria of Hoek & Brown and the strain-softening model shows good agreement with the in-situ measurement. Comparison of numerical modeling with in-situ measurement enables to predict the behaviors of the roadway and to obtain design parameters for the excavation and support at depth.

Finite Element Analysis of Strain Localization in Concrete Considering Damage and Plasticity (손상과 소성을 고려한 콘크리트 변형률 국소화의 유한요소해석)

  • 송하원;나웅진
    • Computational Structural Engineering
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    • v.10 no.3
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    • pp.241-250
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    • 1997
  • The strain localization of concrete is a phenomenon such that the deformation of concrete is localized in finite region along with softening behavior. The objective of this paper is to develop a plasticity and damage algorithm for the finite element analysis of the strain-localization in concrete. In this paper, concrete member under strain localization is modeled with localized zone and non-localized zone. For modeling of the localized zone in concrete under strain localization, a general Drucker-Prager failure criterion by which the nonlinear strain softening behavior of concrete after peak-stress can be considered is introduced in a thermodynamic formulation of the classical plasticity model. The return-mapping algorithm is used for the integration of the elasto-plastic rate equation and the consistent tangent modulus is also derived. For the modeling of non-localized zone in concrete under strain localization, a consistent nonlinear elastic-damage algorithm is developed by modifying the free energy in thermodynamics. Using finite element program implemented with the developed algorithm, strain localization behaviors for concrete specimens under compression are simulated.

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An Experimental Study on Fracture Energy of Plain Concrete

  • Lee, Jaeha;Lopez, Maria M.
    • International Journal of Concrete Structures and Materials
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    • v.8 no.2
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    • pp.129-139
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    • 2014
  • In this study, the concrete fracture energy was obtained using the three point notched beam test method developed by Hillerborg et al. (Cem Concr Res 6(6):773-782, 1976). A total of 12 notched concrete beams were tested under two different loading conditions: constant stroke control and constant crack mouth opening displacement (CMOD) control. Despite individual fracture energies obtained from the two different loading conditions showing some variation, the average fracture energy from both loading conditions was very similar. Furthermore, the results obtained support the idea that a far tail constant "A" could change the true fracture energy by up to 11 %, if it is calculated using CMOD instead of LVDT. The far tail constant "A" is determined using a least squares fit onto a straight line according to Elices et al. (Mater Struct 25(148):212-218, 1992) and RILEM report (2007). It was also observed that the selection of the end point can produce variations of the true fracture energy. The end point indicates the point in the experiment at which to stop. An end point of 2 mm has been recommended, however, in this study other end points were also considered. The final form of the bilinear softening curve was determined based on Elices and Guinea's methods (1992, 1994) and RILEM report (2007). This paper proposes a bilinear stress-crack opening displacement curve according to test results as well as the CEB-FIP model code.

Fatigue Behavior of Welded Joints in HT60 Grade TMCP Steel (HT60급 TMCP강 용접부의 피로 거동)

  • Yong, Hwan Sun;Kim, Seok Tae;Cho, Yong Sik
    • Journal of Korean Society of Steel Construction
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    • v.8 no.4 s.29
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    • pp.133-133
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    • 1996
  • Application of the relationship $da/dN=C({\Delta}K)^{m}$ is effective in the analysis of fatigue crack growth life. The values of material constant C and m have great influences on the predicted fatigue life and the relationship between fatigue crack growth rate(da/dN) and stress intensity factor range(${\Delta}K$) is effective in fatigue crack growth behavior. In this paper, fatigue crack growth behavior of the welded joints in HT60 grade TMCP(Thermo Machanical Control Process) steel have been studied. To evalute the fatigue crack growth rates of HT60 grade TMCP steel, fatigue test was performed by base metal(BM), heat affected zone(HAZ) and weld metal(WM) in TMCP steel at room temperature. We determined the relationship of $da/dN-{\Delta}K$ by correlation between C and m obtained from the Paris-Erdogan power law data supplied HT60 grade TMCP steel. The obtained results from this study indicate that fatigue crack growth rate of TMCP steel is not influenced by softening effect which occurs in the HAZ when high heat input weld is carried out. Softening effects, which affect fatigue properties. are shown that it is not affected to the fatigue growth rates significantly.

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Evaluation of Crack Propagation and Post-cracking Hinge-type Behavior in the Flexural Response of Steel Fiber Reinforced Concrete

  • Gali, Sahith;Subramaniam, Kolluru V.L.
    • International Journal of Concrete Structures and Materials
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    • v.11 no.2
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    • pp.365-375
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    • 2017
  • An experimental evaluation of crack propagation and post-cracking behavior in steel fiber reinforced concrete (SFRC) beams, using full-field displacements obtained from the digital image correlation technique is presented. Surface displacements and strains during the fracture test of notched SFRC beams with volume fractions ($V_f$) of steel fibers equal to 0.5 and 0.75% are analyzed. An analysis procedure for determining the crack opening width over the depth of the beam during crack propagation in the flexure test is presented. The crack opening width is established as a function of the crack tip opening displacement and the residual flexural strength of SFRC beams. The softening in the post-peak load response is associated with the rapid surface crack propagation for small increases in crack tip opening displacement. The load recovery in the flexural response of SFRC is associated with a hinge-type behavior in the beam. For the stress gradient produced by flexure, the hinge is established before load recovery is initiated. The resistance provided by the fibers to the opening of the hinge produces the load recovery in the flexural response.

An analytical and computational study on energy dissipation along fracture process zone in concrete

  • Zhao, Yanhua;Xu, Shilang;Li, Zongjin
    • Computers and Concrete
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    • v.1 no.1
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    • pp.47-60
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    • 2004
  • The influence of the fracture process zone (FPZ) on the fracture properties is one of the hottest topics in the field of fracture mechanics for cementitious materials. Within the FPZ in front of a traction free crack, cohesive forces are distributed in accordance with the softening stress-separation constitutive relation of the material. Therefore, further crack propagation necessitates energy dissipation, which is the work done by the cohesive forces. In this paper $g_f$, the local fracture energy characterizing the energy consumption due to the cohesive forces, is discussed. The computational expression of $g_f$ in the FPZ can be obtained for any stage during the material fracture process regarding the variation of FPZ, whether in terms of its length or width. $G_{fa}$, the average energy consumption along the crack extension region, has also been computed and discussed in this paper. The experimental results obtained from the wedge splitting tests on specimens with different initial notch ratios are employed to investigate the property of the local fracture energy $g_f$ and the average value $G_{fa}$ over the crack extension length. These results can be used to indicate the influence of the FPZ. Additionally, changes in the length of the FPZ during the fracture process are also studied.

The Propagation Behavior of the Fatigue Crack of the Welded Structural Steel (용접(鎔接)이음한 구조용강(構造用鋼)의 피노귀열진전거동(疲勞龜裂進展擧動))

  • Jung, Young-Hwa;Kim, Ik-Gyeom;Lee, Hyung-Koon;Jung, Jin Suck
    • Journal of Industrial Technology
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    • v.18
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    • pp.117-124
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    • 1998
  • In recently, according to increase the construction rate of steel bridge, it is necessary to develop the high strength, high toughness steel. Thus, this study show to evaluate the fatigue characteristic of SWS 570 B first used within a country. With the weld-joined compact tension specimens compared with each other, that is, transverse and lengthwise about the crack propagation, high and low in the input heat level, the fatigue test were performed. The log-log curves between the fatigue crack propagation rate da/dN and the transition range of the stress intensity factor ${\Delta}K$ ahead the crack tip were drawed, with these data. By using this curve, we obtained C and m which is material constant from Paris-Erdogan power law. The obtained results from this study indicate that fatigue crack growth rate of SWS 570 B is not influenced by softening effect which occurs in the HAZ(heat-affected zone) when high and low heat input weld is carried out. Softening effects, which affect fatigue properties, are shown that it is not affected to the fatigue growth rates significantly.

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Investigation of High Temperature Deformation Behavior in Compression and Torsion of Ti-6Al-4V Alloy (Ti-6Al-4V합금의 비틀림 및 압축변형에 따른 고온변형거동 고찰)

  • Yeom, J.T.;Jung, E.J.;Kim, J.H.;Hong, J.K.;Park, N.K.;Lee, C.S.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2008.05a
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    • pp.435-438
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    • 2008
  • High temperature deformation of Ti-6Al-4V alloy with a lamellar colony microstructure was investigated by hot compression and torsion tests. The torsion and compression tests were carried out under a wide range of temperatures and strain rates with true strain up to 2 and 0.7, respectively. The processing maps were generated on the basis of compression and torsion test data and using the principles of dynamic materials modeling (DMM). The shapes of the strain-stress curves in alpha-beta region and processing maps obtained on the two different tests have been compared with a view to evaluate the effect of the microstructure evolution on the flow softening behavior of Ti-6Al-4V alloy with a lamellar colony microstructure.

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The Low Cycle Fatigue Behavior of Laser Welded Sheet Metal for Different Materials (이종재료 레이저 용접 판재의 저주기 피로 특성)

  • Kim Seog-Hwan;Kwak Dai-Soon;Kim Woong-Chan;Oh Taek-Yul
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.10a
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    • pp.627-631
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    • 2005
  • In this study, low fatigue behavior of laser welded sheet metal were investigated. Before welding, the cross section of butt joint was prepared only by fine shearing without milling process. Specimens were same sheet metal and welding condition that using automobile manufacturing company at present. Butt joint of cold rolled sheet metal was welded by $CO_2$ laser. It is used that welding condition such as laser welding speed was 5.5m/sec and laser output power was 5kW for 0.8mm and 1.2mm sheet metal. The laser weldments were machined same or different thickness and same or different material. In order to mechanical properties of around welding zone, hardness test was performed. Hardness of welding bead is about 2 times greater than base material. We performed the low cycle fatigue tests for obtaining fatigue properties about thickness and the weld line direction of specimen. The results of strain controlled low cycle fatigue test indicate that all specimens occur cyclic softening, as indicated by the decrease in stress to reach a prescribed strain.

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