• 제목/요약/키워드: Model Experimental Research

검색결과 4,707건 처리시간 0.037초

Experimental and numerical study on the collapse failure of long-span transmission tower-line systems subjected to extremely severe earthquakes

  • Tian, Li;Fu, Zhaoyang;Pan, Haiyang;Ma, Ruisheng;Liu, Yuping
    • Earthquakes and Structures
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    • 제16권5호
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    • pp.513-522
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    • 2019
  • A long-span transmission tower-line system is indispensable for long-distance electricity transmission across a large river or valley; hence, the failure of this system, especially the collapse of the supporting towers, has serious impacts on power grids. To ensure the safety and reliability of transmission systems, this study experimentally and numerically investigates the collapse failure of a 220 kV long-span transmission tower-line system subjected to severe earthquakes. A 1:20 scale model of a transmission tower-line system is constructed in this research, and shaking table tests are carried out. Furthermore, numerical studies are conducted in ABAQUS by using the Tian-Ma-Qu material model, the results of which are compared with the experimental findings. Good agreement is found between the experimental and numerical results, showing that the numerical simulation based on the Tian-Ma-Qu material model is able to predict the weak points and collapse process of the long-span transmission tower-line system. The failure of diagonal members at weak points constitutes the collapse-inducing factor, and the ultimate capacity and weakest segment vary with different seismic wave excitations. This research can further enrich the database for the seismic performance of long-span transmission tower-line systems.

Experimental animal models for development of human enterovirus vaccine

  • Jae Min Song
    • Clinical and Experimental Vaccine Research
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    • 제12권4호
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    • pp.291-297
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    • 2023
  • Enterovirus infections induce infectious diseases in young children, such as hand, foot, and mouth disease which is characterized by highly contagious rashes or blisters around the hands, feet, buttocks, and mouth. This predominantly arises from enterovirus A71 or coxsackievirus A16 infections and in severe cases, they can lead to encephalitis, paralysis, pulmonary edema, or even fatality, representing a global health threat. Due to the absence of effective therapeutic strategies for these infections, various experimental animal models are being investigated for the development of vaccines. During the early stages of research on enterovirus infections, non-human primate infections exhibited symptoms like those in humans, leading to their utilization as model animals. However, due to economic and ethical considerations, their current usage is limited. While enterovirus infections do not readily occur in mice, an infection model with mouse-adapted strain in neonatal mice has been employed. Cellular receptors have been identified in human cells, and genetically modified mice expressing these receptors have been used. Most recently, the utilization of Mongolian gerbil model is actively being considered and should be pursued for further animal model development. So, herein, we provide a summarized overview of the current portfolio of available enterovirus infection models, emphasizing their respective advantages and limitations.

Analytical Modeling for Two-story Two-span Reinforced Concrete Frames with Relaxed Section Details

  • Kim, Taewan;Chu, Yurim;Park, Hong-Gun
    • Architectural research
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    • 제20권2호
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    • pp.53-64
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    • 2018
  • A nonlinear analytical model has been proposed for two-span two-story reinforced concrete frames with relaxed section details. The analytical model is composed of beam, column, and beam-column joint elements. The goal of this study is to develop a simple and light nonlinear model for two-dimensional reinforced concrete frames since research in earthquake engineering is usually involved in a large number of nonlinear dynamic analyses. Therefore, all the nonlinear behaviors are modeled to be concentrated on flexural plastic hinges at the end of beams and columns, and the center of beam-column joints. The envelope curve and hysteretic rule of the nonlinear model for each element are determined based on experimental results, not theoretical approach. The simple and light proposed model can simulate the experimental results well enough for nonlinear analyses in earthquake engineering. Consequently, the proposed model will make it easy to developing a nonlinear model of the entire frame and help to save time to operate nonlinear analyses.

종양 모델 연구를 위한 소동물 $[^{18}F]$FDG PET 영상화 (Small Animal Small Animal $[^{18}F]$FDG PET Imaging for Tumor Model Study)

  • 우상근;김경민;천기정
    • Nuclear Medicine and Molecular Imaging
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    • 제42권1호
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    • pp.1-7
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    • 2008
  • PET allows non-invasive, quantitative and repetitive imaging of biological function in living animals. Small animal PET imaging with $[^{18}F]$FDG has been successfully applied to investigation of metabolism, receptor-ligand interactions, gene expression, adoptive cell therapy and somatic gene therapy. Experimental condition of animal handling impacts on the biodistribution of $[^{18}F]$FDG in small animal study. The small animal PET and CT images were registered using the hardware fiducial markers and small animal contour point. Tumor imaging in small animal with small animal $[^{18}F]$FDG PET should be considered fasting, warming, and isoflurane anesthesia level. Registered imaging with small animal PET and CT image could be useful for the detection of tumor. Small animal experimental condition of animal handling and registration method will be of most importance for small lesion detection of metastases tumor model.

Towards a digital twin realization of the blade system design study wind turbine blade

  • Baldassarre, Alessandro;Ceruti, Alessandro;Valyou, Daniel N.;Marzocca, Pier
    • Wind and Structures
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    • 제28권5호
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    • pp.271-284
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    • 2019
  • This paper describes the application of a novel virtual prototyping methodology to wind turbine blade design. Numeric modelling data and experimental data about turbine blade geometry and structural/dynamical behaviour are combined to obtain an affordable digital twin model useful in reducing the undesirable uncertainties during the entire turbine lifecycle. Moreover, this model can be used to track and predict blade structural changes, due for example to structural damage, and to assess its remaining life. A new interactive and recursive process is proposed. It includes CAD geometry generation and finite element analyses, combined with experimental data gathered from the structural testing of a new generation wind turbine blade. The goal of the research is to show how the unique features of a complex wind turbine blade are considered in the virtual model updating process, fully exploiting the computational capabilities available to the designer in modern engineering. A composite Sandia National Laboratories Blade System Design Study (BSDS) turbine blade is used to exemplify the proposed process. Static, modal and fatigue experimental testing are conducted at Clarkson University Blade Test Facility. A digital model was created and updated to conform to all the information available from experimental testing. When an updated virtual digital model is available the performance of the blade during operation can be assessed with higher confidence.

Analysis of hysteresis rule of energy-saving block and invisible multi-ribbed frame composite wall

  • Lin, Qiang;Li, Sheng-cai;Zhu, Yongfu
    • Structural Engineering and Mechanics
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    • 제77권2호
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    • pp.261-272
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    • 2021
  • The energy-saving block and invisible multi-ribbed frame composite wall (EBIMFCW) is a new type of load-bearing wall. The study of this paper focus on it is hysteresis rule under horizontal cyclic loading. Firstly, based on the experimental data of the twelve specimens under horizontal cyclic loading, the influence of two important parameters of axial compression ratio and shear-span ratio on the restoring force model was analyzed. Secondly, a tetra-linear restoring force model considering four feature points and the degradation law of unloading stiffness was established by combining theoretical analysis and regression analysis of experimental data, and the theoretical formula of the peak load of the EBIMFCW was derived. Finally, the hysteretic path of the restoring force model was determined by analyzing the hysteresis characteristics of the typical hysteresis loop. The results show that the curves calculated by the tetra-linear restoring force model in this paper agree well with the experimental curves, especially the calculated values of the peak load of the wall are very close to the experimental values, which can provide a reference for the elastic-plastic analysis of the EBIMFCW.

열방식 마이크로 임프린트 공정을 위한 고분자 재료의 수치적 모델링 (Experimental and Numerical Study on the Viscoelastic Property of Polycarbonate near Glass Transition Temperature for Micro Thermal Imprint Process)

  • 란 슈하이;이혜진;이형욱;송정한;이수훈;준니;이문구
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2009년도 춘계학술대회 논문집
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    • pp.70-73
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    • 2009
  • The aim of this research is to obtain a numerical material model for an amorphous glassy polymer, polycarbonate (PC), which can be used in finite element analysis (FEA) of the micro thermal imprint process near the glass transition temperature. An understanding of the deformation behavior of the PC specimens was acquired by performing tensile stress relaxation tests. The viscoelastic material model based on generalized Maxwell model was introduced for the material near Tg to establish the FE model based on the commercial FEA code ABAQUS/Standard with a suitable set of parameters obtained for this material model from the test data. Further validation of the model and parameters was performed by comparing the analysis of FE model results to the experimental data.

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프랜차이즈 브랜드에서 모델의 매력성 및 적합성이 브랜드 태도와 구매의도에 미치는 영향 (The Influence of Attractiveness and Match-Up of Model on Brand Attitude and Purchase Intention of Franchise Brands)

  • 안병옥;허정무;이동한
    • 한국프랜차이즈경영연구
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    • 제8권4호
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    • pp.7-19
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    • 2017
  • Purpose - The purpose of this study is to investigate the effect of model attractiveness on brand attitude and purchase intention, and examine whether product-model match-up plays a moderating role in the relationship between model attractiveness and brand attitude and purchase intention. The model attractiveness is consist of psychological and physical attractiveness of the model. The authors investigate how product-model match-up influence the strength of the relationship between model attractiveness - brand attitude and purchase intention. The purpose of this is to test whether product-model match-up influence the form and effectiveness of a model attractiveness on brand attitude and purchase intention and suggest the effective and efficient methods in the model selection strategies to increase advertising effectiveness based on the results of this study. Research design, data, and methodology - The experimental design for this study was the between subject design based on 2 group of the psychological attractiveness(high vs. low) × product-model match-up(high vs low) and 2 group of the physical attractiveness(high vs. low) × product-model match-up(high vs low). And a preliminary investigation was conducted to develop experimental stimuli through manipulation check to enhance the external validity of experimental research. The attractiveness of the model and product-model match-up are independent variables and manipulative variables in presentation of experimental stimuli. The self-administered methode experiment was conducted on 300 subjects in four groups constructed according to the independent variables. Result - The findings provide partial support for a moderator for product-model match-up on the model attractiveness - brand attitude and purchase intention. First, the influence of psychological attractiveness and physical attractiveness on brand attitude and purchase intention was shown significant. Also, it was found that the average value of brand attitude and purchase intention according to psychological attractiveness was significantly higher than the average value of brand attitude and purchase intention according to physical attractiveness in additional analysis. Second, the average value of brand attitude and purchase intention were higher when product - model match-up was high in both high and low psychological attractiveness and physical attractiveness of the model. However, in the case of psychological attractiveness, the correlation effect with product - model match-up was significant, but in the case of physical attractiveness, it was not significant. Conclusions - The results of this study suggest that the attractiveness factor should be considered in selecting the ad model by verifying the effect of the attractiveness of the model on the advertising effect. In particular, this study has great significance both academically and practically in terms of suggesting such implications that the advertising effect of psychological attractiveness and physical attractiveness may be different depending on the product type by additional analysis.

Finite Element Model for Wear Analysis of Conventional Friction Stir Welding Tool

  • Hyeonggeun Jo;Ilkwang Jang;Yeong Gil Jo;Dae Ha Kim;Yong Hoon Jang
    • Tribology and Lubricants
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    • 제39권3호
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    • pp.118-122
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    • 2023
  • In our study, we develop a finite element model based on Archard's wear law to predict the cumulative wear and the evolution of the tool profile in friction stir welding (FSW) applications. Our model considers the rotational and translational behaviors of the tool, providing a comprehensive description of the wear process. We validate the accuracy of our model by comparing it against experimental results, examining both the predicted cumulative wear and the resulting changes to the tool profile caused by wear. We perform a detailed comparison between the predictions of the model and experimental data by manipulating non-dimensional coefficients comprising model parameters, such as element sizes and time increments. This comparison facilitates the identification of a specific non-dimensional coefficient condition that best replicates the experimentally observed cumulative wear. We also directly compare the worn tool profiles predicted by the model using this specific non-dimensional coefficient condition with the profiles obtained from wear experiments. Through this process, we identify the model settings that yield a tool wear profile closely aligning with the experimental results. Our research demonstrates that carefully selecting non-dimensional coefficients can significantly enhance the predictive accuracy of finite element models for tool wear in FSW processes. The results from our study hold potential implications for enhancing tool longevity and welding quality in industrial applications.