Philosophical Magazine A最新文献_第3页

Application of a physically consistent theory of brittle fracture 物理一致性脆性断裂理论的应用

Philosophical Magazine A Pub Date : 2002-11-01 DOI: 10.1080/01418610208240429

Jeremy Thurn, R. Cook

{"title":"Application of a physically consistent theory of brittle fracture","authors":"Jeremy Thurn, R. Cook","doi":"10.1080/01418610208240429","DOIUrl":"https://doi.org/10.1080/01418610208240429","url":null,"abstract":"Abstract This paper examines the profile and associated stress field of an equilibrium slit crack in a brittle solid using a mesoscopic fracture model. The model is based on a physically consistent description of crack profiles in solids, developed from an analysis by Chan et al. in which the forms of intersurface cohesive forces are used explicitly. The mesoscopic nature of the problem arises from the embedding of the nonlinear and non-monotonic atomic-scale intersurface cohesive forces and length scales into a classical formulation of the elastic fracture problem. The analysis is used to calculate the full crack profile, encompassing three asymptotic limits: the near-tip Barenblatt zone, a transition zone in which the cohesive forces are still active and the far-field elastic classical zone. The analysis is also used to calculate the stress field surrounding the crack, revealing a finite maximum at the crack tip associated with the interatomic bond strength. A result of the analysis is that very small cracks (such as might occur in microelectronic circuits) have suppressed stress fields that cannot be related to the equilibrium condition of Griffith thermodynamics by the Irwin crack extension exercise and that vary with crack size. The Griffith equilibrium condition itself is unaffected by the modified stress fields and is uniquely defined by the integral of the cohesive forces acting across the faces of the crack.","PeriodicalId":114492,"journal":{"name":"Philosophical Magazine A","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125495445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of silicon substrate amorphization on the kinetics of reaction between a titanium thin film and silicon 硅衬底非晶化对钛薄膜与硅反应动力学的影响

Philosophical Magazine A Pub Date : 2002-11-01 DOI: 10.1080/01418610208239625

C. C. Tan, L. Lu, A. See, L. Chan

引用次数: 0

Coalescence of two particles with different sizes by surface diffusion 两个不同大小的粒子通过表面扩散聚并

Philosophical Magazine A Pub Date : 2002-11-01 DOI: 10.1080/01418610208239630

W. Zhang, P. Sachenko, J. Schneibel, I. Gladwell

引用次数: 13

Fracture characteristics of wood under mode I, mode II and mode III loading 木材在I型、II型和III型载荷下的断裂特性

Philosophical Magazine A Pub Date : 2002-11-01 DOI: 10.1080/01418610208240441

K. Frühmann, A. Reiterer, E. Tschegg, S. Stanzl-tschegg

引用次数: 34

Study of crack tip deformation in FeAl and NiAl crystals with optical interference microscopy and atomic force microscopy 用光学干涉显微镜和原子力显微镜研究FeAl和NiAl晶体裂纹尖端变形

Philosophical Magazine A Pub Date : 2002-11-01 DOI: 10.1080/01418610208240437

M. Göken, F. Thome, H. Vehoff

{"title":"Study of crack tip deformation in FeAl and NiAl crystals with optical interference microscopy and atomic force microscopy","authors":"M. Göken, F. Thome, H. Vehoff","doi":"10.1080/01418610208240437","DOIUrl":"https://doi.org/10.1080/01418610208240437","url":null,"abstract":"Abstract The elastic and plastic deformation at crack tips in stoichiometric single crystals of FeAl and NiAl were investigated by atomic force microscopy and optical interference microscopy. Crack propagation and plastic deformation were observed during in-situ loading in an atomic force microscope. Soft oriented NiAl crystals with and without 0.14 wt% Fe doping were investigated, and the plastic deformation in front of the crack tip is analysed by slip steps on the surface. Doping with Fe leads to a more ductile behaviour. Optical interference microscopy is an excellent technique to measure the elastic deformation around loaded crack tips on a large lateral scale. The elastic constants cij of both materials were determined with ultrasonic techniques. Because of the strong anisotropy of these intermetallic compounds the elastic out-of-plane displacement field is asymmetric. The elastic displacements measured at crack tips in FeAl and NiAl bend specimens are significantly different, which is interpreted as arising from the differences in the elastic constants. To determine the stress intensity factor from the elastic displacements around crack tips the stress state near the intersection of a crack tip and a free surface is analysed. Analytical calculations of the stress field around cracks for isotropic solids by Benthem are compared with finite-element simulations of the stress field on the surface of four-point bend specimens.","PeriodicalId":114492,"journal":{"name":"Philosophical Magazine A","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125939306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Fundamentals of fracture 裂缝基本原理

Philosophical Magazine A Pub Date : 2002-11-01 DOI: 10.1080/01418610208240428

S. Roberts

{"title":"Fundamentals of fracture","authors":"S. Roberts","doi":"10.1080/01418610208240428","DOIUrl":"https://doi.org/10.1080/01418610208240428","url":null,"abstract":"The papers in this issue of Philosophical Magazine A are a selection from work presented at the 6th International Conference on the Fundamentals of Fracture, held at the Royal Agricultural College, Cirencester, UK, between 26th and 30th March 2001. The meeting was attended by 87 delegates; 33 oral and 60 poster presentations were given. The work presented at the meeting covered a broad range, but was focused tightly on theory, modelling and experiment (ideally all three in combination), exploring and giving insight into the basic processes of fracture. The scope was broadened from that of previous meetings in the series, to include work on fundamentals of fatigue and on fracture of engineering materials, in addition to the ‘traditional’ topics: theory of fracture processes, atomisticand dislocation-based models of fracture, and experiments on simple, model, materials. Speakers were encouraged to present work and ideas in process of development, and ideas that might be controversial; hence some papers of this type have been published in this volume despite referees disagreeing to some extent with the arguments presented by the authors. All papers generated considerable discussion, both in the lecture theatre and in the conference bar, which doubled as the poster area. While it is perhaps invidious to single out particular presentations, the natural inclination of delegates to relax and enjoy topics outside the ‘normal’ meant that papers on fracture of snow and wood and the pre-dinner lecture on the fracture","PeriodicalId":114492,"journal":{"name":"Philosophical Magazine A","volume":"91 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117154924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 35

Fiducial mark and nanocrack zone formation during thin-film delamination 薄膜分层过程中基准标记和纳米裂纹区形成

Philosophical Magazine A Pub Date : 2002-11-01 DOI: 10.1080/01418610208240449

A. Volinsky, N. Moody, M. Kottke, W. Gerberich

引用次数: 9

Energetics of nucleation of half dislocation loops at a surface crack 表面裂纹中半位错环形核的能量学

Philosophical Magazine A Pub Date : 2002-11-01 DOI: 10.1080/01418610208240431

Guanshui Xu

引用次数: 9

Some aspects of photon emission of polycrystalline ceramics during fracture 多晶陶瓷断裂时光子发射的几个方面

Philosophical Magazine A Pub Date : 2002-11-01 DOI: 10.1080/01418610208240438

K. Yasuda, M. Shimada, Y. Matsuo

引用次数: 10

Transmission electron microscopy observations and micromechanical/continuum models for the effect of hydrogen on the mechanical behaviour of metals 氢对金属力学行为影响的透射电子显微镜观察和微力学/连续体模型

Philosophical Magazine A Pub Date : 2002-11-01 DOI: 10.1080/01418610208240451

P. Sofronis, I. Robertson

{"title":"Transmission electron microscopy observations and micromechanical/continuum models for the effect of hydrogen on the mechanical behaviour of metals","authors":"P. Sofronis, I. Robertson","doi":"10.1080/01418610208240451","DOIUrl":"https://doi.org/10.1080/01418610208240451","url":null,"abstract":"Abstract In-situ deformation studies in a transmission electron microscope equipped with an environmental cell have shown that solute hydrogen increases the velocity of dislocations, decreases the stacking-fault energy, and increases the stability of edge character dislocations. Theoretical modelling has established that the hydrogen atmospheres formed at dislocations through the elastic interaction cause a change in the stress field of the dislocation-hydrogen complex in such a manner as to reduce the interaction energy between it and other elastic obstacles. Consequently, solute hydrogen increases the mobility of dislocations, which will be localized to regions of high hydrogen concentration. On the basis of this material softening on the microscale, a solid mechanics analysis of the hydrogen solute interaction with material elastoplasticity demonstrates that localization of the deformation in the form of bands of intense shear can occur on the macroscale. Thus, the present combined experimental and numerical/analytical results provide a clear explanation for the hydrogen-enhanced localized plasticity mechanism of hydrogen embrittlement.","PeriodicalId":114492,"journal":{"name":"Philosophical Magazine A","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114497841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 82