The strain dependent characteristics of hard coatings make the vibration analysis of hard-coated composite structure become a challenging task. In this study, the modeling and the analysis method of a hard-coated comp...The strain dependent characteristics of hard coatings make the vibration analysis of hard-coated composite structure become a challenging task. In this study, the modeling and the analysis method of a hard-coated composite beam was developed considering the strain dependent characteristics of coating material. Firstly, based on analyzing the properties of hard-coating material, a high order polynomial was adopted to characterize the strain dependent characteristics of coating materials. Then, the analytical model of a hard-coated composite beam was created by the energy method. Next, using the numerical method to solve the vibration response and the resonance frequencies of the composite beam, a specific calculation flow was also proposed. Finally,a cantilever beam coated with Mg O ＋ Al2_O_3 hard coating was chosen as the study case; under different excitation levels, the resonance region responses and the resonance frequencies of the composite beam were calculated using the proposed method. The calculation results were compared with the experiment and the linear calculation, and the correctness of the created model was verified. The study shows that compared with the general linear calculation, the proposed method can still maintain an acceptable precision when the excitation level is larger.展开更多
The results of a theoretical and finite element (FE) investigation of a two-material impression creep test method, using a rectangular indenter, are presented. The method uses a general formulation for steady-state cr...The results of a theoretical and finite element (FE) investigation of a two-material impression creep test method, using a rectangular indenter, are presented. The method uses a general formulation for steady-state creep deformation for multi-material components in conjunction with the results of FE analyses. The practical application of the proposed technique, in determining the secondary creep properties of heat-affected zone (HAZ) materials in welds, for which conventional creep testing methods cannot be used, is considered. A number of numerical examples are used to describe solution procedures and to verify the method.展开更多
Delayed γ-ray spectroscopy of^(185)Au was studied at the Argonne Gas-Filled Analyzer.A new isomer at an excitation energy of 1504.2(4) keV with a half-life of 630(80) ns was identified via γ-γ coincidence analysis,...Delayed γ-ray spectroscopy of^(185)Au was studied at the Argonne Gas-Filled Analyzer.A new isomer at an excitation energy of 1504.2(4) keV with a half-life of 630(80) ns was identified via γ-γ coincidence analysis,decaying via a 294.8(3) keV transition.Based on Weisskopf estimates,the multipolarity of the 295 keV transition is assigned to be E1,M1,E2,or M2.Possible configurations for this new isomer are discussed based on configurationconstrained potential energy surface calculations.展开更多
This paper focuses on the numerical study of heat and moisture transfer in clothing assemblies,based on a multi-component and multiphase flow model which includes heat/moisture convection and conduction/diffusion as w...This paper focuses on the numerical study of heat and moisture transfer in clothing assemblies,based on a multi-component and multiphase flow model which includes heat/moisture convection and conduction/diffusion as well as phase change.A splitting semi-implicit finite volume method is proposed for solving a set of nonlinear convection-diffusion-reaction equations,in which the calculation of liquid water content absorbed by fiber is decoupled from the rest of the computation.The method maintains the conservation of air,vapor and heat flux(energy).Four types of clothing assemblies are investigated and comparison with experimental measurements are also presented.展开更多
The complex nature of coastal ecosystems and their protection require a deeper understanding of land cover change and dynamics.Although a number of ecological studies have been conducted to realise this important obje...The complex nature of coastal ecosystems and their protection require a deeper understanding of land cover change and dynamics.Although a number of ecological studies have been conducted to realise this important objective,little information is available regarding the quantification of this land cover change.The role of mangroves as living barriers was under appreciated prior to the 2004 tsunami event.In this paper,we investigate the buffering functions of mangroves in the 2004 tsunami by employing the methodology developed in our companion paper.We focus more on mangrove distribution patterns in different buffer zones before and after the 2004 tsunami.The presence of mangroves before and after the event was statistically significant for the North(χ^(2)=154.08,p50.001)and Upper South(χ^(2)=62.25,p50.001).We observed positive linear relationships suggesting a loss of mangrove resulted into a gain of barren and sand land cover as a result of a devastating impact from the 2004 tsunami event.There are pockets of inland tsunami inundations and penetrations in the North and Upper-South in part owing to the river mouth profiles and dense mangrove trees.Although the North and Upper South Regions of the study area with large mangrove forest areas suffered slight damages,these regions put up a strong buffer against the tsunami suggesting that mangrove forests play a significant role in shoreline protection.展开更多
基金supported by the National Natural Science Foundation of China(Grant 51375079)the Fundamental Research Funds for the Central Universities of China(Grant N140301001)
文摘The strain dependent characteristics of hard coatings make the vibration analysis of hard-coated composite structure become a challenging task. In this study, the modeling and the analysis method of a hard-coated composite beam was developed considering the strain dependent characteristics of coating material. Firstly, based on analyzing the properties of hard-coating material, a high order polynomial was adopted to characterize the strain dependent characteristics of coating materials. Then, the analytical model of a hard-coated composite beam was created by the energy method. Next, using the numerical method to solve the vibration response and the resonance frequencies of the composite beam, a specific calculation flow was also proposed. Finally,a cantilever beam coated with Mg O ＋ Al2_O_3 hard coating was chosen as the study case; under different excitation levels, the resonance region responses and the resonance frequencies of the composite beam were calculated using the proposed method. The calculation results were compared with the experiment and the linear calculation, and the correctness of the created model was verified. The study shows that compared with the general linear calculation, the proposed method can still maintain an acceptable precision when the excitation level is larger.
基金the Engineering&Physics Science Research Council(EPSRC)the Institution of Mechanical Engineers(IMechE),UK,Ior financial support.
文摘The results of a theoretical and finite element (FE) investigation of a two-material impression creep test method, using a rectangular indenter, are presented. The method uses a general formulation for steady-state creep deformation for multi-material components in conjunction with the results of FE analyses. The practical application of the proposed technique, in determining the secondary creep properties of heat-affected zone (HAZ) materials in welds, for which conventional creep testing methods cannot be used, is considered. A number of numerical examples are used to describe solution procedures and to verify the method.
基金Supported by the National Natural Science Foundation of China (12405140, 12135004, 11961141004, U2032138, 12275369)the Natural Science Foundation of Gansu Province, China (24JRRA033)+4 种基金financial support from the STFCfunded by the Chinese Academy of Sciences President's International Fellowship Initiative (2020VMA0017)Supported by the U.S. Department of Energy, Office of Nuclear Physics, (DE-AC02-06CH11357, DE-FG02-94ER41041 (UNC), DE-FG02-97ER41033 (TUNL))supported by the Slovak Research and Development Agency (APVV-22-0282)Slovak Grant Agency VEGA (1/0019/25)。
文摘Delayed γ-ray spectroscopy of^(185)Au was studied at the Argonne Gas-Filled Analyzer.A new isomer at an excitation energy of 1504.2(4) keV with a half-life of 630(80) ns was identified via γ-γ coincidence analysis,decaying via a 294.8(3) keV transition.Based on Weisskopf estimates,the multipolarity of the 295 keV transition is assigned to be E1,M1,E2,or M2.Possible configurations for this new isomer are discussed based on configurationconstrained potential energy surface calculations.
基金The research of Ye and Sun was supported in part by a grant from CityU(7001926)The research of Huang is supported by the Natural Science and Engineering Council(NSERC)and the Mathematics of Information Technology and Complex Systems(MITACS)of Canada.The research of Fan is supported by Hong Kong Polytechnic University(Project No.G-U165).
文摘This paper focuses on the numerical study of heat and moisture transfer in clothing assemblies,based on a multi-component and multiphase flow model which includes heat/moisture convection and conduction/diffusion as well as phase change.A splitting semi-implicit finite volume method is proposed for solving a set of nonlinear convection-diffusion-reaction equations,in which the calculation of liquid water content absorbed by fiber is decoupled from the rest of the computation.The method maintains the conservation of air,vapor and heat flux(energy).Four types of clothing assemblies are investigated and comparison with experimental measurements are also presented.
文摘The complex nature of coastal ecosystems and their protection require a deeper understanding of land cover change and dynamics.Although a number of ecological studies have been conducted to realise this important objective,little information is available regarding the quantification of this land cover change.The role of mangroves as living barriers was under appreciated prior to the 2004 tsunami event.In this paper,we investigate the buffering functions of mangroves in the 2004 tsunami by employing the methodology developed in our companion paper.We focus more on mangrove distribution patterns in different buffer zones before and after the 2004 tsunami.The presence of mangroves before and after the event was statistically significant for the North(χ^(2)=154.08,p50.001)and Upper South(χ^(2)=62.25,p50.001).We observed positive linear relationships suggesting a loss of mangrove resulted into a gain of barren and sand land cover as a result of a devastating impact from the 2004 tsunami event.There are pockets of inland tsunami inundations and penetrations in the North and Upper-South in part owing to the river mouth profiles and dense mangrove trees.Although the North and Upper South Regions of the study area with large mangrove forest areas suffered slight damages,these regions put up a strong buffer against the tsunami suggesting that mangrove forests play a significant role in shoreline protection.
