• Title/Summary/Keyword: structural evaluation

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Performance evaluation of in-service open web girder steel railway bridge through full scale experimental investigations

  • Sundaram, B. Arun;Kesavan, K.;Parivallal, S.
    • Structural Monitoring and Maintenance
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    • v.6 no.3
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    • pp.255-268
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    • 2019
  • Civil infrastructures, such as bridges and tunnels are most important assets and their failure during service will have significant economic and social impact in any country. Behavior of a bridge can be evaluated only through actual monitoring/measurements of bridge members under the loads of interest. Theoretical analysis alone is not a good predictor of the ability of a bridge. In some cases, theoretical analyses can give less effect than actual since theoretical analyses do not consider the actual condition of the bridge, support conditions, level of corrosion and damage in members and connections etc. Hence actual measurements of bridge response should be considered in making decisions on structural integrity, especially in cases of high value bridges (large spans and major crossings). This paper describes in detail the experimental investigations carried out on an open web type steel railway bridge. Strain gages and displacement transducers were installed at critical locations and responses were measured during passage of locomotives. Stresses were evaluated and extrapolated to maximum design loading. The responses measured from the bridge were within the permissible limits. The methodology adopted shall be used for assessing the structural integrity of the bridge for the design loads.

The Durability Performance Evaluation of Automotive Components in the Virtual Testing Laboratory (차량 부품의 내구성 평가를 위한 가상시험실 구축)

  • Kim, Gi-Hoon;Kang, Woo-Jong;Kim, Dae-Sung;Ko, Woong-Hee;Lim, Jae-Yong
    • Transactions of the Korean Society of Automotive Engineers
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    • v.14 no.3
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    • pp.68-74
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    • 2006
  • The evaluation of durability performance in Virtual Testing Laboratory(VTL) is a new concept of vehicle design, which can reduce the automotive design period and cost. In this study, the multibody dynamics model of a car is built with a reverse engineering design. Hard points and masses of components are measured by a surface scanning device and imported into CAD system. In order to simulate the non-linear dynamic behavior of force elements such as dampers and bushes, components and materials are tested with specialized test equipments. An optimized numerical model for the damping behavior is used and the hysteresis of bush rubber is considered in the simulation. Loads of components are calculated in VTL and used in the evaluation of durability performance. In order to verify simulation results, loads of components in the vehicle are measured and durability tests are performed.

Structural and Fatigue Strength Evaluation of a Fairlead Chain Stopper for Floating Offshore Wind Turbines (10 MW급 부유식 해상풍력장치용 패어리드 체인스토퍼의 구조 및 피로 강도 평가)

  • Youngjae Yu;Sanghyun Park;Youngsik Jang;Sangrai Cho
    • Journal of Wind Energy
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    • v.14 no.4
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    • pp.5-12
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    • 2023
  • In this study, a structural and fatigue strength evaluation of the Fairlead Chain Stopper (FCS) was performed as a part of the development of a disconnectable mooring system to be applied to 10MW floating offshore wind power generation systems. To estimate the load acting on the FCS, a 10 MW semi-submersible floater was designed using the 10 MW wind turbine developed by Technical University of Denmark(DTU). The minimum breaking load (MBL) of the grade R5 and 147mm mooring chain was applied for the FCS strength analysis. The fatigue load was obtained from the coupled analysis results conducted by a collaborating research institute. The structural and fatigue safety of FCS were evaluated in accordance with DNV codes. From the evaluation results, it was confirmed that the FCS satisfies the structural and fatigue safety requirements.

Development of the Structural Condition Evaluation Technique for Asphalt Pavements Using Falling Weight Deflectometer Deflections (Falling Weight Deflectometer 처짐값을 이욤한 아스팔트 포장체의 구조적 상태 평가기법 개발)

  • Son, Jong-Chul;Rhee, Suk-Keun;An, Deok-Soon;Park, Hee-Mun
    • International Journal of Highway Engineering
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    • v.8 no.4 s.30
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    • pp.115-124
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    • 2006
  • The objectives of this paper are to develop the structural condition evaluation technique using Falling Weight Deflectometer deflections and propose the structural condition criteria for asphalt pavements. To figure out correlation between surface deflections and critical pavement responses, the synthetic database has been established using the finite element pavement structural analysis program. A regression approach was adopted to develop the pavement response model that can be used to compute the stresses and strains within pavement structure using the FWD deflections. Based on the pavement response model, the procedure for assessing the structural condition of pavement layers was proposed in this study. To validate the condition evaluation procedure for asphalt pavements, the FWD test, dynamic cone penetrometer test, and repeated triaxial compression test were conducted on 11 sections of national highway and 8 sections of local road. Test results indicate that the tensile strain at the bottom of AC layer and AC elastic modulus were good indicators for estimating the stiffness characteristics of AC layer. For subbase layer, the BDI value and compressive strain on top of the subbase layer were appropriate to predict the structural capacity of subbase layer. The BCI value and compressive strain on top of the subgrade were found to be good indicators for evaluating the structural condition of the subgrade. The evaluation criteria for structural condition in asphalt pavements was also proposed in this paper.

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Structural Integrity Evaluation of Nozzle Assembly using Acoustic Emission Technique (음향방출법을 응용한 노즐 조립체의 구조건전성 평가)

  • 설창원;이기범
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.34 no.10
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    • pp.32-39
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    • 2006
  • An acoustic emission technique was applied to the structural strength test for the structural integrity evaluation of the nozzle assembly. These AE results were compared with data from the strain gages and displacement transducer. NDT using X-ray technique was performed to improve the test reliability before and after each test. In this structural integrity evaluation of the nozzle assembly, the internal crack initiation in the structure could not be precisely revealed by the strain and displacement results but the location and load level of the initiated crack could be precisely evaluated by using AE technique. From this test, it was proven that some new cracks can be generated in composite liner of nozzle assembly under the unexpected load due to interference between obturator and nozzle and these can be a cause of the unexpected abnormal failure.

Study on Evaluation Method of Structural Integrity for Cone-Type Composite Lattice Structures with Hexagonal Cell (육각 격자구조를 갖는 콘형 복합재 격자구조체의 구조안전성 평가 기법 연구)

  • Im, Jae-Moon;Kang, Seung-Gu;Shin, Kwang-Bok;Lee, Sang-Woo
    • Composites Research
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    • v.31 no.4
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    • pp.156-160
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    • 2018
  • In this paper, evaluation method of structural integrity for cone-type composite lattice structures with hexagonal cell was conducted. A finite element analysis was used to evaluate the structural integrity of cone-type composite lattice structure. The finite element model for evaluation of structural integrity was generated using solid element. In order to consider the difference in mechanical properties between intersection and non-intersection part, the mechanical properties were applied considering the fiber volume fraction of each part. Compression test of cone-type composite lattice structure were conducted for verification of evaluation method of structural integrity. The analysis result showed 2% errors in displacement and good agreement with test result.

Difference of Deterioration According to Exposed Condition of Column in Wooden Traditional Building (노출 환경에 따른 목조 고건축물 기둥의 열화 차이)

  • Kim, Gwang-Chul;Bae, Mun-Sung;Lee, Jun-Jae
    • Journal of the Korean Wood Science and Technology
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    • v.31 no.2
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    • pp.58-68
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    • 2003
  • Capacity assessment of structural member must be ahead of the safety assessment of wooden traditional building. Capacity assessment of structural member has been dependent on empirical method with visual inspection even now. Safety assessment of building, however, can be more correct and reasonable provided non-destructive evaluation technique that scientific and logic would be used to evaluate the capacity of structural member. For that purpose, non-destructive evaluation technique was applied to column among many structural members of wooden traditional building to examine the possibility of capacity assessment of structural member. And then, those data will be used as a basic data for capacity assessment of structural member in a following study. Specially, deterioration progress levels of column according to exposed condition were measured. Similar results were obtained as compared with results of visual inspection, so there was a good possibility of application for non-destructive evaluation technique.

Sensitivity Evaluation and Approximate Optimization Analysis for Structure Design of Module Hull Type Trimaran Pontoon Boat (모듈 선체형 삼동 폰툰 보트의 구조설계 민감도 평가와 근사 최적화 해석)

  • Bo-Youp Choi;Chang-Ryeon Son;Joon-Sik Son;Min-Ho Park;Chang-Yong Song
    • Journal of the Korean Society of Industry Convergence
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    • v.26 no.6_3
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    • pp.1279-1288
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    • 2023
  • Recently, domestic leisure boats have been actively researching eco-friendly product development to enter the global market. Since the hulls of existing leisure boats are mainly made of fiber reinforced plastic (FRP) or aluminum, design techniques for securing structural safety by applying related materials have been mainly studied. In this study, an initial structural design safety assessment of a trimaran pontoon leisure boat with a modular hull structure and eco-friendly high-density polyethylene (HDPE) material was conducted, and sensitivity evaluation and optimization analysis for lightweight design were performed. The initial structural design safety assessment was carried out by creating a finite element analysis model and applying the loading conditions specified in the ship classification regulation to check whether the specified allowable stresses are satisfied. For the sensitivity evaluation, the influence of stress and weight of each hull structural member was evaluated using the orthogonal array design of experiments method, and an approximate model based on the response surface method was generated using the results of the design of experiments. The optimization analysis set the thickness of the hull structural members as the design variable and considered the optimal design formulation to minimize the weight while satisfying the allowable stress. The algorithm of the optimization analysis applied the Gradient-population Based Optimizer (GBO) to improve the accuracy of the optimal solution convergence while reducing the numerical cost. Through this study, the optimal design of a newly developed eco-friendly trimaran pontoon leisure boat with a weight reduction of 10% was presented.