• Journal of Welding and Joining
• /
• 제6권3호
• /
• pp.21-26
• /
• 1988

The behavior of angular distortion in butt joint wleding of thin plate structure is investigated with an experimental model and partially with a computational model. The experimental model studying the effects of specimene size and degree of restraint on the angular distorion offers a good method for analyzing the behavior of the distrotion. In addition, the distrotion during welding was demonstrated by both experimental measurement and numericla prediciton. The facts evealed in this study are as follows : 1) distrotion angles were changed with variations of specimene wldth. 2) With the restraint, angular distrotion was reduced to 20% to that of free joint. 3) After the restraint being removed, the effect of restraint was also remained. 4) Same heat input per unit thickness caused same amount of distortion. 5) The mode of angular distortion was expected to be changed with expected to be changed with time, i.e. convex movement during heating and concave one during cooling.

• Structural Engineering and Mechanics
• /
• 제35권6호
• /
• pp.699-715
• /
• 2010

This paper investigates the structural responses of axially restrained steel beams under fire conditions by a nonlinear finite element method. The axial restraint is represented by a linear elastic spring. Different parameters which include beam slenderness ratio, external load level and axial restraint ratio are investigated. The process of forming a mid-span plastic hinge at the mid-span under a rising temperature is studied. In line with forming a fully plastic hinge at mid-span, the response of a restrained beam under rising temperature can be divided into three stages, viz. no plastic hinge, hinge forming and rotating, and catenary action stage. During catenary action stage, the axial restraint pulls the heated beam and prevents it from failing. This study introduces definitions of beam limiting temperature $T_{lim}$, catenary temperature $T_{ctn}$ and warning time $t_{wn}$. Influences of slenderness ratio, load level and axial restraint ratio on $T_{lim}$, $T_{ctn}$ and $t_{wn}$ are examined.

• 성인간호학회지
• /
• 제19권4호
• /
• pp.583-592
• /
• 2007

Purpose: The purposes of this study were to explore and describe the use of restraint on patients and to generate a grounded theory of how the use of restraint affects patients who have been restrained. Methods: Interview data from seven patients with physical restraint was analyzed using the Strauss and Corbin's grounded theory method. Data were collected and analyzed simultaneously. Unstructured and in-depth interviews were conducted retrospectively with patients recalling their memories of ICU following their transfer to general unit. Results: 'Safety belt' was emerged as a core category and it reflected that physical restraint provided a sense of security to patients. On the basis of core category, a model of the experience process of restrained patients in ICU was developed. The experience process were categorized into four stages: resistance, fear, resignation, and agreement. Stages of these proceeds appeared to have been influenced by the nurses' attitude and caring behavior such as the frequency of nurse-patient interaction, repetition of explanation, and empathetic understanding. Conclusion: These findings indicate that patients have mixed feelings towards restraint use, although negative feelings were stronger than positive ones. The result of this study will help nurses make effective nursing intervention.

• 기본간호학회지
• /
• 제18권1호
• /
• pp.28-36
• /
• 2011

Purpose: The purpose of this study were to develop a new restraint for the intensive care units (ICU) and to investigate the application effect in comparison with a control group using existing restraints. Method: A non-equivalent control group non-synchronized quasi-experimental research design was used. The participants were 40 (control 20, experimental 20) patients who were recruited by convenience sampling the ICU of a university hospital. To avoid contamination of the experiment, data for the control group were collected prior to the experimental group. Measurement variables were edema and skin damage (redness and abrasion) at the application site, and nurses' perceived convenience in applying restraints. Results: Three days after applying the restraint, amount of edema at the application site was small and incidence of skin damage decreased in the experimental group in comparison with the control group. Also, score for application convenience measured by the nurses was higher in for the newly developed restraint than for existing restraints. Conclusion: Results indicate that the newly developed restraint has lower effects such as edema and skin damage and is more convenient compared with existing restraints, and is therefore recommended for patients in the ICU.

• 한국의료질향상학회지
• /
• 제20권1호
• /
• pp.42-57
• /
• 2014

Objective: The objective of this research was to develop a guideline for more effective use of physical restraint on patients in the intensive care unit and training the nurses on it and applying it on clinical practice to assess its effectiveness. Method: This research analyzed the before and after effect of the development of a guideline for physical restraint by dividing the category into nurse and patient. In the case of nurse, a comparison of knowledge and nursing service regarding the use of physical restraint from before the training on physical restraint guideline(Jan. 2011) and after the training on physical restraint guideline(Dec. 2011) was made. In the case of patient, a comparison of physical restraint usage rate and average usage time, the number of unplanned extubation cases were compared from before the use of physical restraint (Jan.~Apr. 2011) and after the use of physical restraint (Sep.~Dec. 2011) were made. Result: After the training on the physical restraint guideline, the knowledge of the nurse and the nursing practice showed notable improvement by (p<0.000) and (p<0.048) respectively and in patient, physical restraint usage rate and average time of usage decreased by (p<0.001) and (p<0.001) respectively. And despite the decrease in the number of cases in which the physical restraint was used, the number of unplanned extubation cases remained the same. Conclusion: Physical restraint guideline training and guideline usage can be stated to have brought out positive effect in both the nurse and patient. In order to maintain such positive effects, continuous training is necessary and continuous revaluation is necessary, regarding knowledge and nursing practices.

• 콘크리트학회지
• /
• 제8권5호
• /
• pp.111-122
• /
• 1996

본 연구에서는 매스콘크리트의 외부구속도의 특성을 검토하기 위하여, 타설높이를 1.0m로 고정시킨 상태에서 타설블럭의 밑면길이와 타설높이와의 비(L/H), 하부 구속체의 탄성계수($E_r$) 등 매스콘크리트 구조물에서 특히 외부구속에 영향을 미치는 인자를 대상으로 parameter study를 실시하여 각 인자가 온도응력에 미치는 영향을 검토하고 각 인자간의 상호 영향도에 대해서도 검토하였다. 검토결과, 외부구속에 의해 발생하는 응력은 단면 높이방향으로 거의 직선분포를 이루고 있으며, L/H나 구속체 탄성계수의 크기에 따라서도 다르고 타설한 콘크리트의 강도발현에 따른 탄성계수의 증가 및 체적변화로 이해서 재령별로도 그 영향이 각각 다르다는 것을 알았다. 또한, 외부구속은 축방향구속과 휨방향구속으로 나누어 평가할 수 있으며, 외부구속이 약한 경우는 휨방향구속이 탁월하고, 외부구속이 강한 경우는 축방향구속이 탁월하다는 것을 알았다. 그리고타설높이 H를 1.0cm로 제한 시킨 경우에 ACI 207 위원회법으로 계산한 결과를 본 해석결과와 비교한 결과, ACI위원회법으 외부고속이 약한 경우에는 본 해석결과보다 큰 값으로 평가하고, 외부구속이 강한 경우에는 작게 평가하고 있음을 알았다.

• 대한기계학회논문집A
• /
• 제33권6호
• /
• pp.590-599
• /
• 2009

In this paper, a method of modeling seat belts on crew seat during dynamic seat testing was studied. The body segments of the occupant were modeled with joints. The joints consisted with various stiffnesses, dampings, and frictions. Three types of seat belt restraint systems were investigated. The analysis for on the injury assessment of helicopter's crew under drop impact was conducted. The effectiveness of the seat belt system for crashworthiness and safety was evaluated. As the results of impact analysis, head, neck and spine of the crew can be easily damaged in the vertical direction more than the longitudinal direction. Based on the verified model, behavior of human body was studied with three-point restraint systems. The displacement and injury level of the 12-point restraint system was the smallest.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2001년도 가을 학술발표회 논문집
• /
• pp.417-424
• /
• 2001

It is very important to know the magnitude of the restraint moment which is appeared at the inner-support of the continuous PSC girder. The Age-adjusted Effective Modulus Method(AEMM) is used to get the magnitude of the restraint moment for the purpose of the time-dependent analysis of the concrete. The important factors for computing the restraint moment, the creep coefficient and the shrinkage strain are computed by comparing Korean specification with AC1209. The restrain moment is created by the individual continuity load. The main purpose of this paper is ensuring the safety of structure by acquiring the time-dependent stress acting on the concrete because the process of construction is getting difficult due to the advance of technology. The negative moment at the inner-support is decreased about 55% by introducing the process of making the continuous bridge relatively early.

• International Journal of Advanced Culture Technology
• /
• 제8권2호
• /
• pp.159-164
• /
• 2020

The response analysis of frame structure with open section beams considering warping conditions and short duration load have been performed. When a beam of frame structure is subjected under torsional moment, the cross section will deform a warping as well as twist. For some thin-walled sections warping will be large, and accompanying warping restraint will induce axial and shear stresses and reduce the twist of beam which stiffens the beam in torsion. Because of impact or blast loads, the wave propagation effects become increasingly important as load duration decreases. This paper presents that a warping restraint in finite element model effects the behavior of beam deformation, dynamic mode shape and response analysis. The computer modelling of frame is discussed in linear beam element model and linear thin shell element model, also presents a correlation between computer predicted and actual experimental results for static deflection, natural frequencies and mode shapes of frame. A method to estimate the number of normal modes that are important is discussed.

• 자동차안전학회지
• /
• 제13권4호
• /
• pp.99-105
• /
• 2021

Vehicle occupant postures are anticipated to vary more widely during automated driving and to become more significant in terms of the autonomous vehicle safety. Experimental and computational approaches are needed to investigate and evaluate occupant behaviors during automated driving in general. However the validity and effect of such occupant postures are unknown, thus it is necessary to examine occupant behaviors and injury countermeasures for various occupant postures. This study was focused on the development and evaluation of restraint system model for occupant behavior examinations in the first step according to autonomous vehicle occupant safety. The finite element models of dummy and restraint system were set up and simulation results showed overall model performance and safety tolerances of different reclined occupant postures during frontal impact loading.