• Title/Summary/Keyword: Total Stress Analysis

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Relationship between Job Stress and Self-esteem of Physical Therapists (물리치료사의 자아존중감과 직무스트레스의 상관관계)

  • Ro, Hyo-Lyun
    • The Journal of Korean Physical Therapy
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    • v.22 no.1
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    • pp.83-90
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    • 2010
  • Purpose: This study aimed to determine the degree of job stress and self-esteem of physical therapists as well as the correlation between the two variables. Method: This study targeted 218 physical therapists of Busan City, and was carried out from July 16 to August 6, 2009 as survey research. A structured questionnaire referring to advance researches was used as a research tool. Job stress symptoms were measured one a 5 point scale, the higher the point total, the higher the job stress. Self-esteem was measured on a 4 point scale, the higher the point total, the lower the self-esteem. After data collection we determined descriptive statistics, and did reliability analysis, factor analysis, Spearman's correlation analysis, and regression analysis. Results: Reliability analysis indicated that reliability for the job stress questionnaire was 0.93 and for the self-esteem was 0.83. The average job stress score of physical therapists was 1.19 points which was not high. The average self-esteem score was 1.76 points, whichwas high. It appeared that the higher the self-esteem, the lower the job stress. Also, self-esteem had an influence on psychological symptoms among job stress factors. Conclusion: Job stress and self-esteem of physical therapists are well-correlated and influence each other. Accordingly, self-esteem can be used as a variable for adjusting job stress of physical therapists.

Evaluation of Biomechanical Stability of Newly Developed Revision Total Knee Arthroplasty through Strain and Stress Distribution Analysis within the Tibia: Finite Element Analysis (경골 내 변형률 및 응력 분포 특성 분석을 통한 새로이 개발된 재치환용 인공슬관절의 생체역학적 안정성 평가: 유한요소해석)

  • Han, Paul;Jang, Young-Woong;Yoo, Oui Sik;Kim, Jung Sung;Kim, Han Sung;Lim, Dohyung
    • Journal of Biomedical Engineering Research
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    • v.34 no.1
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    • pp.14-23
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    • 2013
  • In this study, biomechanical stability of the newly developed revision total knee arthroplasty (rTKA) was evaluated through strain and stress distribution analysis within the implanted proximal tibia using a three-dimensional finite element (FE) analysis. 2000N of compressive load (about 3 times body weight) was applied to the condyle surface on spacer, sharing by the medial (60%) and lateral (40%) condyles simulating a stance phase before toe-off. The results showed that PVMS within the revision total knee arthroplasty and the proximal tibia were less than yield strength considering safe factor 4.0 (rTKA: less than 10%, Cortical bone: less than 70%, Cancellous bone: less than 70%). The materials composed of them and the strain and stress distributions within the proximal tibia were generally well matched with those of a traditional revision total knee arthoplasty (Scorpio TS revision system, Stryker Corp., Michigan, USA) without the critical damage strain and stress, which may reduce the capacity for bone remodeling, leading to bone degeneration. This study may be useful to design parameter improvement of the revision total knee arthoplasty in biomechanical stability point of view beyond structural stability of revision total knee arthoplasty itself.

Fatigue and Vibration Analysis on Engine Parts (엔진 부품에 대한 피로 및 전동해석)

  • Cho, Jae-Ung;Han, Moon-Sik
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.19 no.3
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    • pp.321-325
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    • 2010
  • This study analyzes the results with the simulation of heat transfer, structural stress, fatigue and vibration on main parts of engine. The maximum temperature is shown by $300.73^{\circ}C$ on the upper part of piston with the heat transfer. Maximum total deformation or equivalent stress is shown by 65.31mm or 21364MPa respectively at the upper plane of piston with the structural analysis inclusive of heat transfer. The minimum life is shown by the cycle less than $10^7$ at the part of crankshaft with the fatigue analysis. The frequency with the maximum amplitude of deformation is shown by 14Hz. Maximum total deformation or equivalent stress is shown respectively by 93.99mm on the upper plane of piston or 42625MPa at the part connected with crack shaft and connecting rod at 14Hz. The durability of engine design can be verified by using the analysed result of this study.

Elevated Temperature Design of KALIMER Reactor Internals Accounting for Creep and Stress-Rupture Effects

  • Koo, Gyeong-Hoi;Bong Yoo
    • Nuclear Engineering and Technology
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    • v.32 no.6
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    • pp.566-594
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    • 2000
  • In most LMFBR(Liquid Metal Fast Breed Reactor) design, the operating temperature is very high and the time-dependent creep and stress-rupture effects become so important in reactor structural design. Therefore, unlike with conventional PWR, the normal operating conditions can be basically dominant design loading because the hold time at elevated temperature condition is so long and enough to result in severe total creep ratcheting strains during total service lifetime. In this paper, elevated temperature design of the conceptually designed baffle annulus regions of KALIMER(Korea Advanced Liquid MEtal Reactor) reactor internal strictures is carried out for normal operating conditions which have the operating temperature 53$0^{\circ}C$ and the total service lifetime of 30 years. For the elevated temperature design of reactor internal structures, the ASME Code Case N-201-4 is used. Using this code, the time-dependent stress limits, the accumulated total inelastic strain during service lifetime, and the creep-fatigue damages are evaluated with the calculation results by the elastic analysis under conservative assumptions. The application procedures of elevated temperature design of the reactor internal structures using ASME Code Case N-201-4 with the elastic analysis method are described step by step in detail. This paper will be useful guide for actual application of elevated temperature design of various reactor types accounting for creep and stress-rupture effects.

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Seismic Risk Analysis of Quay wall Considering Effective Stress (유효응력효과를 고려한 안벽의 지진위험도 평가)

  • Kim, So Yeon;Kim, Dong Hyawn
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.29 no.1
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    • pp.1-11
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    • 2017
  • Seismic risk analysis was performed based on the total stress and effective stress of caisson type quay wall and pier type quay wall. In order to consider the effective stress effect, the pore pressure of the ground was distributed, using Byrne(1991) simple formula to estimate parameter and applied to the finn model. Through the results of seismic risk analysis according to the total stress and effective stress analysis method, the necessity of effective stress analysis in the seismic design of the quay wall installed on the soft ground was confirmed.

Aging Effect on Femoral Stress Fracture Risk in Pin-hole after Computer-navigated Total Knee Arthroplasty (컴퓨터 네비게이션 슬관절 전치환술에서 노화에 따른 핀 홀에서의 대퇴골 골절 위험성)

  • Park, Hyung-Kyun;Park, Won-Man;Kim, Yoon-Hyuk
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1518-1520
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    • 2008
  • Recent clinical studies have shown that computer navigation for total knee arthroplasty (TKA) provides improved component alignment accuracy. However, femoral stress fracture after computernavigated TKA have been reported due to the pin hole and we hypothesized that osteoporosis would be one of the key factors in pin hole fracture after computer-navigated TKA. We investigated the von-Mises stress around the femoral pin-hole for different elastic modulli and ultimate stresses and four different pin penetration modes to understand the aging effect on femoral stress fracture risk after computer-navigated TKA by finite element analysis. In this study, aging effect was shown to increase the femoral stress fracture risk for all pin penetration modes. Especially, aging effect was shown dramatically in the transcortical pin penetration mode.

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Basic Study on Impact Analysis of Automobile (자동차 충돌 해석에 관한 기초 연구)

  • Cho, Jae-Ung;Min, Byung-Sang;Han, Moon-Sik
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.8 no.1
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    • pp.64-70
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    • 2009
  • This study is to analyze the impact of automotive body with computer simulation. The total deformation, equivalent strain and strain and principal stress are analyzed respectively in case of front, rear and side impacts. The maximum total deformation of side impact is more than 6 times as large as that of rear impact. The maximum equivalent strain or stress of side impact is more than 4 times as large as that of rear impact. These deformation, strain and stress of front impact are a little more than those of rear impact. The maximum principal stress of side impact is more than 4.5 times as large as that of rear impact. This stress of front impact is a little more than that of rear impact.

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Finite Element Analysis Approach for the Stress of Digging Part of Garlic Harvesters (유한요소해석을 이용한 마늘 수확기 굴취부의 응력분석)

  • Kim, Kyu-Bong;Lee, Myung-Hee;Kim, Dae-Cheol;Cho, Yongjin
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.19 no.11
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    • pp.78-86
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    • 2020
  • A stress analysis was performed to verify the stability of the digging part of a garlic harvester. A finite element analysis was performed to examine the distribution and concentrated loads on the digging part of the blade and contact plate. Moreover, the stability and maximum deformation of the digging part were determined. Under a distributed load, the maximum principal stress, total deformation, and minimum safety factor ranged from 64-128 MPa, 0.35-0.70 mm, and 2.9-5.7, respectively. The analysis results for the distribution load indicated that the maximum stress occurred at the center of the blade. In contrast, under the concentrated load, the maximum principal stress, total deformation, and minimum safety factor ranged from 66-247 MPa, 0.35-0.79 mm, 1.48-5.53, respectively. The analysis results for the concentrated load indicated that stress and deformation were larger toward the edge and center, respectively.

Stress Analysis of Femoral Stems on Non-Cemented Total Hip Replacement - A Three-Dimensional Finite Element Analysis -

  • Kim, Sung-Kon;Chae, Soo-Won;Jeong, Jung-Hwan
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.11
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    • pp.263-266
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    • 1997
  • Three dimensional numerical model based on the finite element method(FEM) were developed to predict the mechanical behavior of hip implants. The purpose of this study is to investigate the stress distribution of two types of cementless total hip replacement femoral component -a straight stem and a curved stem, and to compare their effect on the stress shielding between two types by three dimensional finite element method. The authors analyzed von Mises stress in the cortex & stem and compared the stress between the straight and the curved stem. In comparison of stresses between two different design of femoral stem, there was 25% more decrease of stress in straight stem than curved stem in the medial cortex at proximal region. The straight stem had consistently much lower stresses than the curved stem throughout the whole medial cortex with maximum 70% reduction of stress. However, there was little change in stress between nature and 2 implanted femur throughout the lateral cortex. Stress of femoral stem was much higher in the straight stem than the curved stem up to 60%. The straight stem had more chance of stress shielding and a risk of fatigue fracture of the stem compared with the curved stem in noncement hip arthroplasty. In design of femoral stem still we have to consider to develop design to distribute more even stress on the proximal medial cortex.

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Method for soil-structure dynamic interaction analysis(II) (지반-구조물의 동적 상호작용 해석법(II))

  • 황성춘
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2001.04a
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    • pp.152-162
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    • 2001
  • Comparison of results from two different methods of soil-structure dynamic interaction analysis is presented. Two methods include transfromed static and seismic response analyes. In seismic response analysis, the difference in result of total stress analysis relative to effective stress analysis is investigated.

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