• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2003년도 가을 학술발표회 논문집
• /
• pp.577-584
• /
• 2003

Tension tests of half-thickness concrete containment wall elements and material tests were conducted to derive a crack pattern and constitutive law of concrete. Main test variables are reinforcement ratio and the applied load ratio in two direction, and its effect on the behavior of reinforced concrete panel subjected to biaxial tension is investigated. Based on the test results, analytical expression is derived for the stress-strain relationship of concrete in tension. Ultimate analyses of reinforced concrete panels are carried out by a general purpose structural analysis computer program(ABAQUS), and its results are compared with the test results. The present analysis focuses on the effects of pre-analysis prior to test of specimens. These ultimate tensile analyses as pre-analysis are essential and important to design an effectual scheme of test.

• 한국정보통신설비학회:학술대회논문집
• /
• 한국정보통신설비학회 2009년도 정보통신설비 학술대회
• /
• pp.49-53
• /
• 2009

If you are installing communications cables in the pipeline based on the kind of cable installation tension within the allowed range of the tension must be maintained. The tension of the installation affected by the cable types, cable jacketed status, cross-sectional shape of the pipeline, the substance present in the pipeline, pipeline linear, the direction of the cable is installed. Depending on the size of the cable installation tension fatal influence on the quality of communication, or, at worst, the cable can be cut. In this paper, test bed for building a pipeline and using optical cable and such cable tension was measured. Freedom of access to the pipeline used in the experiment, and installed in conjunction with the cable tension was measured. It possible for the cable installation to determine whether a duplicate, and have compared the actual measured tension value and the theoretical expression.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2017년도 학술발표회
• /
• pp.514-514
• /
• 2017

Floating breakwaters were treated as solid bodies without any perforation in previous studies. In this study, however, a floating breakwater is perforated to allow the partial absorption of the energy produced by incident waves and an air chamber is placed in the upper part to control the breakwater draft. A series of laboratory experiments for a floating breakwater installed with a mooring system are carried out. In general, a mooring system can be classified by the number of mooring points, the shape of the mooring lines, and the degree of line tension. In this study, a four-point mooring is employed since it is relatively easier to analyze the measured results. Furthermore, both the tension-leg and the catenary mooring systems have been adopted to compare the performance of the system. In laboratory experiments, the hydraulic characteristics of a floating breakwater were obtained and analyzed in detail. Also, a hydraulic model test was carried out on variable changes by changing the mooring angle and thickness of perforated wall. A hydraulic model was designed to produce wave energy by generating a vortex with the existing reflection method. Analysis on wave changes was conducted and the flow field around the floating breakwater and draft area, which have elastic behavior, was collected using the PIV system. From the test results the strong vortex was identified in the draft area of the perforated both-sides-type floating breakwater. Also, the wave control performance of the floating breakwater was improved due to the vortex produced as the tension in the mooring line decreased.

• International Journal of Concrete Structures and Materials
• /
• 제10권2호
• /
• pp.163-175
• /
• 2016

This paper presents a revised procedure for computation of double-K fracture parameters of concrete split-tension cube specimen using weight function of the centrally cracked plate of finite strip with a finite width. This is an improvement over the previous work of the authors in which the determination of double-K fracture parameters of concrete for split-tension cube test using weight function of the centrally cracked plate of infinite strip with a finite width was presented. In a recent research, it was pointed out that there are great differences between a finite strip and an infinite strip regarding their weight function and the solution of infinite strip can be utilized in the split-tension specimens when the notch size is very small. In the present work, improved version of LEFM formulas for stress intensity factor, crack mouth opening displacement and crack opening displacement profile presented in the recent research work are incorporated. The results of the double-K fracture parameters obtained using revised procedure and the previous work of the authors is compared. The double-K fracture parameters of split-tension cube specimen are also compared with those obtained for standard three point bend test specimen. The input data required for determining double-K fracture parameters for both the specimen geometries for laboratory size specimens are obtained using well known version of the Fictitious Crack Model.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
• /
• pp.475-480
• /
• 2002

Tension tests of six half-thickness concrete containment wall elements were conducted as part of a Korea Atomic Energy Research Institute (KARRI) program. The aim of the KAERI test program is providing a test-verified analytical method for estimating capacities of concrete reactor containment buildings under internal overpressurization from postulated degraded core accidents. The data from the tests reported herein should be useful for benchmarking method that requires modeling of material behavior including concrete cracking and reinforcement/concrete interaction exhibited by the test. Major test variable is the compressive strength of concrete and its effect on the behavior of prestressed concrete panel subjected to biaxial tension.

• 한국간호교육학회지
• /
• 제14권2호
• /
• pp.273-281
• /
• 2008

Purpose: This study was performed to investigate the effects of aromatherapy on headache, stress and immune response of students with tension-type headache. Method: This study employed a two-group pre-post test study design. Data was collected from 44 subjects. Twenty-two subjects were assigned to the experimental group and received aromatherapy massage every other day for 3 weeks, but the other 22 subjects were in the control group and did not receive any intervention. Experiment had been conducted from Apr. 9 through Aug. 25, 2001 and intensity of headache, stress response (serum cortisol, life stress) and immune response(T-cell and natural killer cell ratio) were measured in the course of aromatherapy for both experimental group and control group. Data were analyzed by using $X^2$-test, t-test, Paired t-test and repeated measures ANOVA. Result: Headache scores, serum cortisol levels and life stress scores were significantly decreased in the experimental group after treatment compared to the control group. Conclusion: These findings is suggested that the aromatherapy could be an effective nursing intervention in relaxing and relieving the pain caused by tension-type headache for students.

• Computers and Concrete
• /
• 제3권4호
• /
• pp.197-212
• /
• 2006

Modeling of physically non-linear behavior becomes more and more important for the analysis of SFRC structures in practical applications. From this point of view we will present an effective, three-dimensional constitutive model for SFRC, that is also easy to implement in commercial finite element programs. Additionally, the finite element analysis should only require standard material parameters which can be gained easily from conventional experiments or which are specified in appropriate building codes. Another important point is attaining the material parameters from experimental data. The procedures to determine the material parameters proposed in appropriate codes seem to be only approximations and are unsuitable for precise structural analysis. Therefore a finite element analysis of the test itself is used to get the material parameters. This process is also denoted as inverse analysis. The efficiency of the proposed constitutive model is demonstrated on the basis of numerical examples and their comparison to experimental results. In the framework of material parameter identification the idea of a new, indirect tension testing procedure, the "Modified Tension Test", is adopted and extended to an easy-to-carry-out tension test for steel fiber reinforced concrete specimens.

• 한국전문물리치료학회지
• /
• 제19권4호
• /
• pp.32-37
• /
• 2012

The purpose of this study was to investigate the quantitative data of downward pulling tension in subjects with scapular downward rotation syndrome (SDRS) before and after 6-week self scapular upward rotation exercise (SURE) program. Eleven subjects with bilateral SDRS. The downward pulling tension(DPT) was measured digital tension-meter. The tension force data were collected using a surface electromyography before and after a 6-week self-scapular SURE program. The significance of difference between pre- and post-program was assessed using a paired t-test, with the level of significance set at ${\alpha}$=.05. The results showed that significant differences between pre- and post-SURE program were found for DPT (p<.05). These findings suggest that 6-week self SURE program is effective for reducing DPT in subjects with SDRS. Additionally, our DPT measurement can be useful for maintaining shoulder position and providing quantitative data between pre- and post-SURE program during passive correction of scapular position test.

• Composites Research
• /
• 제33권3호
• /
• pp.169-175
• /
• 2020

콘형 복합재 격자 구조체의 강성 평가를 위한 두 종류의 시편 단위 압축 및 인장 시험을 수행하였으며 유한요소해석 결과와 비교하였다. 구조체는 높이별로 반경이 변화하는 콘형이므로 단순 압축 및 인장 시험이 어려우므로 시험 수행이 가능한 형태의 시편 및 지그를 제작하여 시험을 수행하였다. 압축 시험이 가능하도록 단위 격자 구조체를 Subelement 형태로 가공하였으며, 압축 시험을 수행하여 측정된 섬유방향 압축 변형률을 유한요소해석 결과와 비교하여 헬리컬 리브의 강성을 확인하였다. 후프 리브의 강성 평가를 위해서는 구조체에서 후프 링 시편을 가공하여 인장 시험을 수행하였다. 후프 링에 인장 하중을 가하여 굽힘 변형이 크게 발생하도록 하였으며, 두께 방향 섬유체적비를 고려한 유한요소해석 결과와 비교하여 후프 리브의 강성을 확인하였다.

• 대한기계학회논문집A
• /
• 제28권4호
• /
• pp.352-361
• /
• 2004

One important element of the Leak-Before-Break analysis of nuclear piping is how to determine relevant fracture toughness (or the J-resistance curve) for nonlinear fracture mechanics analysis. The practice to use fracture toughness from a standard C(T) specimen is known to often give conservative estimates of toughness. To improve the accuracy, this paper proposes a new method to determine fracture toughness using a nonstandard testing specimen, curved wide-plate in tension. To show validity of the proposed curved wide-plate test, the J-resistance curve from the full-scale pipe test is compared with that from the curved wide-plate test and that from the C(T) specimen. It is shown that the J-resistance curve form the curved wide-plate tension test is similar to, but that from the C(T) specimen is lower than, the J-resistance curve from the full-scale pipe test. Further validation is performed by investigating crack-tip constraint conditions via detailed 3-D FE analyses, which shows that the crack-tip constraint condition in the curved wide-plate tension specimen is indeed similar to that in the full-scale pipe under bending.