• Journal of the Earthquake Engineering Society of Korea
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• v.9 no.5 s.45
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• pp.29-40
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• 2005

The purpose of this study is to investigate the inelastic behavior of precast segmental prestressed concrete bridge piers. A computer program, named RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology), for the analysis of reinforced concrete structures was used. Material nonlinearity is taken into account by comprising tensile, compressive and shear models of cracked concrete and a model of reinforcing steel. An unbonded tendon element based on the finite element method, that can represent the interaction between tendon and concrete of prestressed concrete member, is used. A joint element is newly developed to predict the inelastic behaviors of segmental joints. The proposed numerical method for the inelastic behavior of precast segmental prestressed concrete bridge piers is verified by comparison with reliable experimental results.

• Journal of the Earthquake Engineering Society of Korea
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• v.11 no.1 s.53
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• pp.79-87
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• 2007

This paper presents an analysis procedures of Joints in precast segmental prestressed concrete bridge piers. A computer program, named RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology), for the analysis of reinforced concrete structures was used. Material nonlinearity is taken into account by comprising tensile, compressive and shear models of cracked concrete and a model of reinforcing steel. An unbended tendon element based on the finite element method, that can represent the interaction between tendon and concrete of prestressed concrete member, is used. A joint element is newly developed to predict the inelastic behaviors of segmental joints. The proposed numerical method for joints in precast segmental prestressed concrete bridge piers is verified by comparison with reliable experimental results.

• Korean Journal of Oriental Medicine
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• v.2 no.1
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• pp.337-380
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• 1996

'Nei Jing(內徑)' first defined the interrelationship of the true and tile false between evil factor affecting health(雅氣) and vital essence energy(精氣). According to 「'Nei Jing(內徑)', the above interrelationship is explained as 'If state of evil domination is considered as sthenia-syndrome(雅氣盛則實), if the consumption of healthy energy Is considered as asenia-syndrome(精氣尊則虛): 'Nei Jing(內徑)', proposed major features of the medicall treatment by 'regluate the vatal energy of asthenia and sthenia, treat the sthenia-syndrome by purgation, and treat the asenia-syndrome by therapy of invigoration(調其氣之虛實, 實則瀉之, 虛則補之): The above interrelationship was interpreted as 'treat the asthenia-syndrome of child organ by invigorating the mother organ(虛者補其母)'in the 69th of 'The Classic on Difficulty',(難經 六十九難). Go-Mu(高武) of Myung-dynasty describe therapy for invigoration and purgation of itself-meridian(自經 補瀉法), which locating acupuncture points according to the Therorr of Five Element in the five shu points of itself-meridian(自經 五유穴), based on the generation in the ${\ulcorner}$A Synthetical Book of Acupuncture and Moxibustion(針灸聚英)${\lrcorner}$, Sae-hyun Jang(張世賢) further extended location acupuncture points of the five shu points to the other-meridian in the ${\ulcorner}$Gyeo Jung Do Ju Nan Gyung(校正圖註難經)${\lrcorner}$ Sa-Ahm's 5 Element Acupuncture Method(舍嚴五行鍼法) was originated in 1644, the middle of the Yi-dynasty. It linked the reinforcing and reducing in acupuncture therapy which incorporated tlle asthenia-syndrome and sthenia-syndrome of the hollow organs, based on principle of the Yin Yang 5 Element Theory(陰陽五行學說), not only to the generation in the 5 element(相生關係) but also to the restriction in the 5 element(相剋關係). Furthermore it was devised for the medical treatment by comning therapy for invigoration and purgation of itself-meridian(自經 補瀉法) with that of the other-meridian. Even though many original forms(正形) of the therapy for invigoration and purgation of the Yin Yang 5 Element Theory comply with the principle of the generation and the restriction based on the principle of the Yin Yang 5 Element Theory are abailable, variational forms(變形) are also recognized by examining the nature of the Sa-Ahm's 5 Element Acupuncture Method(舍嚴五行鍼法), For this reason, it is very difficult to understand the Sa-Ahm's 5 Element Acupuncture Method(舍嚴五行鍼法) thoroughly. therefore, those variational forms are obstacles for the beginners to study the Sa-Ahm's 5 Element Acupuncture Method. In order to understand the principle of the practical clinical application of the Sa-Ahm's 5 Element Acupuncture Method, this study investigated which principle was based on the variations of the locating acupuncture points' method for the acupuncture prescription.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.3
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• pp.16-20
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• 2018

Steel Fiber reinforced self-compacting concrete (SFRSCC) has been widely used in a number of structures, such as ordinary civil infrastructures, sky scrapers, nuclear power plants, hospitals, dams, channels and etc. Thanks to its short and discrete reinforcing fibers, its performance, including tensile strength, ductility, toughness and flexural strength gets much better in comparison with ordinary self-compacting concrete (SCC) without any reinforcing fibers. Despite all these aforementioned advantages of SFRSCC, its performance highly depends on fiber's orientation. In case of short discrete fibers, the orientation of fibers is completely random and cannot be controlled during pumping process. If fibers distribution inside hardened state concrete are randomly distributed, it leads to less resistance potential of concrete element, especially in terms of flexural and tensile strength. The maximum expected strength may not be achieved. Therefore, fiber alignment has been considered as one of the important factors in SFRSCC. To address this issue, this study investigates the effects of concrete matrix's density and inlet velocity on fiber alignment during the pumping process using a finite element method.

• Journal of the Korea Concrete Institute
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• v.22 no.4
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• pp.511-517
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• 2010

The purpose of this study is to investigate the shear behavior of prestressed concrete deep beams and to provide the data for development of improved design criteria. The accuracy and objectivity of the assessment process may be enhanced by the use of sophisticated nonlinear finite element analysis program. Hence, in this study, the computer program, named RCAHEST (reinforced concrete analysis in higher evaluation system technology), was used. Material nonlinearity is taken into account by comprising tensile, compressive and shear models of cracked concrete and a model of reinforcing steel. A bonded or unbonded tendon element based on the finite element method, that can represent the interaction between tendon and concrete of prestressed concrete member, is used. The proposed numerical method for the shear behavior of prestressed concrete deep beams is verified by comparing the analytical results with test data by others.

• Journal of the Korean Society of Radiology
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• v.13 no.7
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• pp.947-953
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• 2019

The purpose of this study was to manufacture a wrist brace using a computerized tomography system, clinical design software (MediACE 3D Program), and 3D printer. After acquiring the Dicom file of the upper limb with a computed tomography, the wrist brace was designed using the MediACE 3D Program to create a "stereolithography" file. The designed wrist brace was printed using a 3D printer. To verify the effectiveness of wrist assistive device manufactured by 3D printing technology, the stress distribution of the pressure and orthosis applied to bone and skin is represented by finite element analysis. It is expected that the wrist brace can be manufactured by reinforcing the part where the damage caused by pressure and breakage of the brace frequently occurs with the result of finite element analysis when producing the wrist brace.

• Journal of Technologic Dentistry
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• v.42 no.4
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• pp.348-354
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• 2020

Purpose: Zirconia is differentiated from other ceramics because of its high resistance to corrosion and wear, excellent flexural strength (900~1400 MPa), and high hardness. Dental zirconia with proven mechanical/biological stability is suitable for the manufacture of implants. However, there are limited in vivo studies evaluating stress distribution in zirconia compared with that in titanium implants and studies analyzing finite elements. This study was conducted to evaluate the stress distribution of the supporting bone surrounding zirconia and titanium implants using the finite element analysis method. Methods: For finite element analysis, a single implant-supported restoration was designed. Using a universal analysis program, eight occlusal points were set in the direction of the occlusal long axis. The occlusal load was simulated at 700 N. Results: The zirconia implant (47.7 MPa) von Mises stress decreased by 5.3% in the upper cortical bone compared with the titanium implant (50.2 MPa) von Mises stress. Similarly, the zirconia implant (20.8 MPa) von Mises stress decreased by almost 4% in the cancellous bone compared with the titanium implant (21.7 MPa) von Mises stress. The principal stress in the cortical and cancellous bone exhibited a similar propensity to von Mises stress. Conclusion: In the supporting bone, the zirconia implant is able to reduce bone resorption caused by mechanically transferred stress. It is believed that the zirconia implant can be a potential substitute for the titanium implant by reinforcing aesthetic characteristics and improving stress distribution.

• Steel and Composite Structures
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• v.21 no.2
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• pp.323-342
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• 2016

To study the effect of collar-plate reinforcement on the static strength of tubular T-joints under axial loading, fundamental research work is carried out from both experimental test and finite element (FE) simulation. Through experimental tests on 7 collar-plate reinforced and 7 corresponding un-reinforced tubular T-joints under axial loading, the reinforcing efficiency is investigated. Thereafter, the static strengths of the above 14 models are analyzed by using FE method, and it is found that the numerical results agree reasonably well with the experimental data to prove the accuracy of the presented FE model. Additionally, a parametric study is conducted to analyze the effect of some geometrical parameters, i.e., the brace-to-chord diameter ratio ${\beta}$, the chord diameter-to-chord wall thickness ratio $2{\gamma}$, collar-plate thickness to chord wall thickness ratio ${\tau}_c$, and collar-plate length to brace diameter ratio $l_c/d_1$, on the static strength of a tubular T-joint. The parametric study shows that the static strength can be greatly improved by increasing the collar-plate thickness to chord wall thickness ratio ${\tau}_c$ and the collar-plate length to brace diameter ratio $l_c/d_1$. Based on the numerical results, parametric equations are obtained from curving fitting technique to estimate the static strength of a tubular T-joint with collar-plate reinforcement under axial loading, and the accuracy of these equations is also evaluated from error analysis.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.60-65
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• 2007

Local buckling behaviors of aluminum square tube beams reinforced by aluminum plates under three point bending loads have been analyzed using experimental tests combined with theoretical and finite element analyses. For this analysis true stresses were determined from applied loads and cross-sectional area records of a tensile specimen with a rectangular cross-section by real-time photographing. True strains were also obtained from in-situ local elongation measurements of the specimen gage portion by the multi-point scanning laser extensometer. Six kinds of aluminum tube beam specimens reinforced by aluminum plates were employed for the bending test. The bending deformation behaviors up to the maximum load analyzed by the numerical simulation agreed well with experimental ones. After passing the maximum load, reinforcing plate hindering the local buckling of the tube beam was debonded from the aluminum tube beam. An aluminum tube beam strengthened by aluminum plate on the upper web showed the most excellent bending capacity, which could be explained on the basis of the neutral axis shift and the local buckling deformation range.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.477-480
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• 2011

The stress analyses of the 'U'-shaped multi-ply reinforced gimbal bellows under high pressure and rotational displacement loadings are performed at the room and cryogenic temperatures. The bellows are used for the Lox pipe line which connects the combustion chamber with the turbopump of a liquid rocket engine. The distributions of the stress, the strains and the contact pressures are obtained from the finite element analysis considering the geometric non-linearities of the contacts between the plies and the material one of the isotropic plasticity. Those are compared with the stress results from EJMA (Expansion Joint Manufacturing Association) standard. Also, the effects of the operating temperature and the reinforcing ring on the stresses are investigated.