Multiple surface cracks and interfacial delamination are the major failure mechanisms in film/substrate systems.The effect of interlayer upon the failure mechanisms of interfacial delamination concomitant to surface c...Multiple surface cracks and interfacial delamination are the major failure mechanisms in film/substrate systems.The effect of interlayer upon the failure mechanisms of interfacial delamination concomitant to surface crack was explored.Finite element model was developed to obtain the stress and energy release rate(ERR),which governs the propagation of interface cracks.The dependences of delamination upon the geometry and constitutive properties of interlayer were examined.The results indicate that the effect of elastic modulus of interlayer on the steady state ERR is insignificant.In cases of different geometrical parameters,however,the steady ERR decreases with the increase of the interlayer thickness.These findings lead to the conclusion that the interlayer constraint has significant effect on the ERR and thus coating life,which can be adopted to modify the ceramic top coat.展开更多
This paper presents an analytical procedure for massive water-sealing barriers(MWSBs)that are made of partially overlapped jet-grouting columns used for deep excavations,in which two crucial factors of the permeabilit...This paper presents an analytical procedure for massive water-sealing barriers(MWSBs)that are made of partially overlapped jet-grouting columns used for deep excavations,in which two crucial factors of the permeability and strength of jet-grouted materials are considered.Subsequently,a calculation example is analyzed and discussed.Results show that“tension failure”mechanism is a major concern for the structural failure during a design of MWSBs.The maximum allowable seepage discharge is a crucial index for the design of MWSBs,which has a significant influence on determining the design parameters of MWSBs.Compared with the design procedure for MWSBs that is proposed in this paper,the design parameters of MWSBs determined by the stability equilibrium and seepage stability equilibrium approaches are conservative due to the fact that it fails to consider the permeability or strength of jet-grouted materials that makes a contribution to the structural safety.Based on the proposed design method,the ranges of both the thickness and depth of MWSBs for a case history of subway excavation in Fuzhou,China were determined.Finally,field pumping test results showed that the water-tightness performance of MWSBs performed at site was quite well.展开更多
Along with the arrival of the economic globalization,the people with different cultural backgrounds communicate with each other more and more frequently. From the superficial level,barriers are not caused by the cultu...Along with the arrival of the economic globalization,the people with different cultural backgrounds communicate with each other more and more frequently. From the superficial level,barriers are not caused by the cultural differences to the communication between people. In fact,there are many in-depth barriers in the cross-cultural communication,and these barriers have hindered the essence of the communication to be deeply recognized,so that the understanding between different cultures is impeded. In this paper,the barriers in the cross-culturalcommunication are concluded based on reading a vast amount of data and also the causes for these barriers are explored,and then the strategies for enhancing the cross-cultural communication are summarized on the basis of a meticulous analysis.展开更多
基金Project(2013CB035700) supported by the National Basic Research Program of ChinaProjects(11272259,11321062,11002104) supported by the National Natural Science Foundation of China
文摘Multiple surface cracks and interfacial delamination are the major failure mechanisms in film/substrate systems.The effect of interlayer upon the failure mechanisms of interfacial delamination concomitant to surface crack was explored.Finite element model was developed to obtain the stress and energy release rate(ERR),which governs the propagation of interface cracks.The dependences of delamination upon the geometry and constitutive properties of interlayer were examined.The results indicate that the effect of elastic modulus of interlayer on the steady state ERR is insignificant.In cases of different geometrical parameters,however,the steady ERR decreases with the increase of the interlayer thickness.These findings lead to the conclusion that the interlayer constraint has significant effect on the ERR and thus coating life,which can be adopted to modify the ceramic top coat.
基金Projects(52090084, 51938008) supported by the National Natural Science Foundation of ChinaProject(2021T140474)supported by the China Postdoctoral Science Foundation。
文摘This paper presents an analytical procedure for massive water-sealing barriers(MWSBs)that are made of partially overlapped jet-grouting columns used for deep excavations,in which two crucial factors of the permeability and strength of jet-grouted materials are considered.Subsequently,a calculation example is analyzed and discussed.Results show that“tension failure”mechanism is a major concern for the structural failure during a design of MWSBs.The maximum allowable seepage discharge is a crucial index for the design of MWSBs,which has a significant influence on determining the design parameters of MWSBs.Compared with the design procedure for MWSBs that is proposed in this paper,the design parameters of MWSBs determined by the stability equilibrium and seepage stability equilibrium approaches are conservative due to the fact that it fails to consider the permeability or strength of jet-grouted materials that makes a contribution to the structural safety.Based on the proposed design method,the ranges of both the thickness and depth of MWSBs for a case history of subway excavation in Fuzhou,China were determined.Finally,field pumping test results showed that the water-tightness performance of MWSBs performed at site was quite well.
文摘Along with the arrival of the economic globalization,the people with different cultural backgrounds communicate with each other more and more frequently. From the superficial level,barriers are not caused by the cultural differences to the communication between people. In fact,there are many in-depth barriers in the cross-cultural communication,and these barriers have hindered the essence of the communication to be deeply recognized,so that the understanding between different cultures is impeded. In this paper,the barriers in the cross-culturalcommunication are concluded based on reading a vast amount of data and also the causes for these barriers are explored,and then the strategies for enhancing the cross-cultural communication are summarized on the basis of a meticulous analysis.
