• 제목/요약/키워드: Structural Stability

검색결과 2,724건 처리시간 0.034초

식생블록옹벽의 구조적 안전성 해석과 보강설계기법 연구 (Development of Strengthening Method and Safety Analysis of Ecological Block and Vegetation Bank Protection)

  • 오병환;조인호;이영생;이근희
    • 한국구조물진단유지관리공학회 논문집
    • /
    • 제7권1호
    • /
    • pp.207-215
    • /
    • 2003
  • Developed is a new environment-friendly concrete-block retaining wall system. The conventional analysis methods are not directly applicable because the proposed concrete-block wall system is made of by interlocking the blocks with shear keys. Therefore, the shear analysis as well as stability analysis have been conducted to secure the safety of block-wall system. Overall slope stability analysis was also performed. An appropriate strengthening method was developed to ensure the safety when the block-wall system is relatively high. The method of analysis for strengthening the concrete-block wall system was also proposed. The proposed environment-friendly concrete block retaining wall system shows reasonable safety and can be a good construction method for retaining walls and river bank walls.

균열발생 지하철 본선구조물의 안정성 연구 (A Study on Stability of Cracked Main Structure in Subway)

  • 우종태;임성순
    • 한국구조물진단유지관리공학회 논문집
    • /
    • 제3권3호
    • /
    • pp.187-194
    • /
    • 1999
  • In this study, a series of items on the safety and stability of cracked main structure in subway are investigated and analyzed. Cracks due to dry contraction under the construction can be found when a tensile stress of cross section is higher than tensile strength at a value of coefficient of dry contraction $200{\times}10^{-6}$. It is concluded that there is no problems when load carrying capacity, that is, an ability of resisting loads of structure is enough in this analytical model. Also, it is concluded that this model has a desirable serviceability because a width of bending crack is lower than allowable one.

  • PDF

절삭력을 고려한 고정밀 연삭기 핵심부품의 구조해석 및 안정성에 관한 연구 (Study on Structural and Stability Analyses of the Main Parts of a High-Precision Grinding Machine Considering the Cutting Force)

  • 김인우;이춘만
    • 한국정밀공학회지
    • /
    • 제32권8호
    • /
    • pp.693-698
    • /
    • 2015
  • Recently, the quality of products after the corresponding machining processes were scrutinized in the interest of maintaining a high product-quality standard. The structure and stability of machine tools are important for the prediction of product quality. A structural analysis needs to be carried out to achieve the stable design of machine tools before the initial design stage in the manufacturing process of a precision product. In this study, a structural analysis was carried out using a finite element analysis (FEA) simulation to obtain the design stability of the main parts of a grinding machine. The sizes and locations of both the maximum stress and deformation in consideration of the cutting force of the chuck, tail stock, and bearing of the grinding machine were analyzed. Finally the grinding machine was successfully developed.

용접 정밀도 향상을 위한 레이저 용접기의 구조개선 (Design of a Laser Welding Machine for the Precision Improvement)

  • 노승훈;정평수;안재우;강희태;이태훈
    • 한국산업융합학회 논문집
    • /
    • 제13권4호
    • /
    • pp.197-203
    • /
    • 2010
  • Laser welding is widely used for precision welding because of superior mechanical properties and high productivity. Generally the accuracy of the welding is determined by the distribution of the bead which is affected by the structural vibrations of the equipment. This study was originated to stabilize a laser welding machine to minimize the bead distribution for the precise joining. The structural properties of the laser welding machine have been investigated to analyze the major factors of the vibrations to cause the bead distribution. The ideas for the design improvement have been applied to the simulation model to identify the effects and further to achieve the stability design and to minimize the bead distribution. The result shows that a few simple design alterations can substantially suppress the structural vibrations and improve the welding accuracy. The procedure used for this study can also be applied to similar welding equipments for improving the structural stability and the welding accuracy.

  • PDF

An Extended Model Evaluation Method under Uncertainty in Hydrologic Modeling

  • Lee, Giha;Youn, Sangkuk;Kim, Yeonsu
    • 한국지반환경공학회 논문집
    • /
    • 제16권5호
    • /
    • pp.13-25
    • /
    • 2015
  • This paper proposes an extended model evaluation method that considers not only the model performance but also the model structure and parameter uncertainties in hydrologic modeling. A simple reservoir model (SFM) and distributed kinematic wave models (KWMSS1 and KWMSS2 using topography from 250-m, 500-m, and 1-km digital elevation models) were developed and assessed by three evaluative criteria for model performance, model structural stability, and parameter identifiability. All the models provided acceptable performance in terms of a global response, but the simpler SFM and KWMSS1 could not accurately represent the local behaviors of hydrographs. Moreover, SFM and KWMSS1 were structurally unstable; their performance was sensitive to the applied objective functions. On the other hand, the most sophisticated model, KWMSS2, performed well, satisfying both global and local behaviors. KMSS2 also showed good structural stability, reproducing hydrographs regardless of the applied objective functions; however, superior parameter identifiability was not guaranteed. A number of parameter sets could result in indistinguishable hydrographs. This result indicates that while making hydrologic models complex increases its performance accuracy and reduces its structural uncertainty, the model is likely to suffer from parameter uncertainty.

반응표면 최적화를 이용한 머드탱크 최적 설계에 관한 연구 (A Study on Optimal Design of Mud Tank with Response Surface Optimization)

  • 남인혁;반임준;임채옥;신성철
    • 한국산업융합학회 논문집
    • /
    • 제26권5호
    • /
    • pp.895-905
    • /
    • 2023
  • Mud tanks used for storing and supplying mud in mud supply systems are essential to secure structural stability according to the mud loads inside the tank. In terms of structural stability of the mud tank can be ensured by increasing the thickness of the structure. However, increasing the thickness may cause a problem of increasing production costs. In addition, this increases the weight of the tank, which can cause problems with the trailer loading weight limitation during transportation. To satisfy both these problems and structural stability, the mud tank should be optimally designed. Therefore, this study conducted an optimum design in consideration of the load of the mud tank through the structural analysis and response surface optimization method in ANSYS.

원격탐사와 지구정보시스템을 이용한 충주지역의 사면안정분석 (Analysis of Slope Stability by Using Remote Sensing and GIS Around Chungju Area)

  • 신현준;이영훈;민경덕;원중선;김윤종
    • 자원환경지질
    • /
    • 제29권5호
    • /
    • pp.615-622
    • /
    • 1996
  • Slope stability analysis was conducted using remote sensing and Geoscientific Information System (GIS) as a part of natural hazard assessment around Chungju area. Landsat TM band 5 and 7 which contain more information about geological structure and geography are chosen and processed to analyse regional geological structure. Through image processing technique such as PCA, HFF, edge detection and enhancement, regional lineament can be mapped and identified. The lineament density map is constructed based on summed length of lineaments per unit area and the study area can be divided into 7 structural domains. Various factors of slope stability analysis such as geology, slope aspect, degree of slope, landcover, water shed as well as characterized structural domain are constructed as a database of GIS. Rating and weighting of each factor for slope stability analysis is decided by considering environmental geological characteristics of study area. Spatial analysis of regional slope stability is examined through overlaying technique of the GIS. The result of areal distribution of slope stability shows that the most unstable area is all over Jaeogae-ni, Hyangsan-ni and Mt. Daedun.

  • PDF

도시 유역 내에서 토지이용에 따른 표토의 특성 비교 및 표토 보전을 위한 시사점 (Comparative Analyses for the Properties of Surface Soils from Various Land Uses in an Urban Watershed and Implication for Soil Conservation)

  • 박은진;강규이
    • 한국환경복원기술학회지
    • /
    • 제12권3호
    • /
    • pp.106-115
    • /
    • 2009
  • Knowledge about how to stabilize soil structure is essential to conserve soil systems and maintain various biogeochemical processes through soil. In urban area, soil structural systems are degraded with inappropriate management and land use and become vulnerable to erosion. We analyzed the structural changes of surface soils with different land uses, i.e., forests, parks, roadside green area, riparian area, and farmlands (soybean fields), in the Anyang Stream Watershed in order to find the factors influencing the stability of soil structure and the implication for better management of surface soil. Soil organic matter contents of other land use soils were only 18~52% of that in forest soils. Soil organic matter increased the stability of soil aggregates in the order of soybean fields < roadsides < riparian < parks < forests and also reduced soil bulk density (increased porosity). The lowest stability of soybean field soils was attributed to the often disturbance like tillage and it was considered that higher stability of park soils comparing to other land use soils except forests was owing to the covering of soil surface with grass. These results suggest that supply of soil organic matter and protection of soil surface with covering materials are very important to increase porosity and stability of soil structure.

종동력을 받는 외팔기둥의 동적 안정성에 미치는 구조감쇠 효과 (Structural Damping Effects on Stability of a Cantilever Column under Sub-tangentially Follower Force)

  • 민동주;박재균;김문영
    • 한국소음진동공학회논문집
    • /
    • 제26권6_spc호
    • /
    • pp.635-643
    • /
    • 2016
  • 안정성 지도(stability map)을 이용하여 부분 종동력(sub-tangentailly follower force)를 받는 외팔 기둥의 동적안정성 이론을 요약한다. Rayleigh 감쇠를 가정하여 내적 및 외적 감쇠효과를 2개의 감쇠비를 통하여 반영하고, 감쇠비 변화에 따른 플러터하중의 변화와 관련된 매개변수 연구를 수행한다. 또한, 종동력을 받는 외팔기둥에 대한 진동수 방정식의 엄밀해를 유도하고, 특정 감쇠비 범위에 대한 안정성 지도를 유한요소 해석결과와 함께 비교/분석한다.