Embrittlement of Cracks at Interfaces.

1995 ◽  
Vol 409 ◽  
Author(s):  
Robb Thomson Emeritus ◽  
A. E. Carlsson

AbstractThis paper presents a synopsis of already published work for cracks on interfaces and new results on the effect of changing the chemistry of the atoms at the interface. Once the appropriate cut-off for the oscillatory singularity in the interface analysis is determined, the physics of the crack is determined in terms of an appropriate driving force for a particular event of interest, and a lattice resistance to the event. Analytic approximations are available for the driving forces, and the lattice resistance is determined on the basis of a block construction for the lattice. We show that for the case where the chemical bonding at the interface is different from that in the matrix, the same ideas are applicable, provided the different chemistry is incorporated correctly in the lattice resistance construction.

1995 ◽  
Vol 408 ◽  
Author(s):  
Robb Thomson ◽  
Emeritus ◽  
A. E. Carlsson

AbstractThis paper presents a synopsis of already published work for cracks on interfaces and new results on the effect of changing the chemistry of the atoms at the interface. Once the appropriate cut-off for the oscillatory singularity in the interface analysis is determined, the physics of the crack is determined in terms of an appropriate driving force for a particular event of interest, and a lattice resistance to the event. Analytic approximations are available for the driving forces, and the lattice resistance is determined on the basis of a block construction for the lattice. We show that for the case where the chemical bonding at the interface is different from that in the matrix, the same ideas are applicable, provided the different chemistry is incorporated correctly in the lattice resistance construction.


Author(s):  
Xiandong Zhou ◽  
Christoph Reimuth ◽  
Peter Stein ◽  
Bai-Xiang Xu

AbstractThis work presents a regularized eigenstrain formulation around the slip plane of dislocations and the resultant non-singular solutions for various dislocation configurations. Moreover, we derive the generalized Eshelby stress tensor of the configurational force theory in the context of the proposed dislocation model. Based on the non-singular finite element solutions and the generalized configurational force formulation, we calculate the driving force on dislocations of various configurations, including single edge/screw dislocation, dislocation loop, interaction between a vacancy dislocation loop and an edge dislocation, as well as a dislocation cluster. The non-singular solutions and the driving force results are well benchmarked for different cases. The proposed formulation and the numerical scheme can be applied to any general dislocation configuration with complex geometry and loading conditions.


1988 ◽  
Vol 92 (18) ◽  
pp. 5086-5094 ◽  
Author(s):  
Sason S. Shaik ◽  
Philippe C. Hiberty ◽  
Gilles Ohanessian ◽  
Jean Michel Lefour

2018 ◽  
Vol 22 (3) ◽  
pp. 194-211 ◽  
Author(s):  
Yongqi Feng ◽  
Tianshu Zhang

Purpose The purpose of this paper is to provide a better understanding of the driving forces and structural changes of China as a market provider for Korea. This paper gives the answers for the following questions: How do China’s final demands trigger the growth of its imports from Korea? And what’s the impact of China’s final demands on the import in different industries? Design/methodology/approach Based on the Multi-Regional Input-Output model and World Input-Output Table database, this paper constructs the non-competitive imports input-output (IO) table of China to Korea. According to this table, we can calculate the induced imports coefficient and comprehensive induced import coefficients of China’s four final demands for imports from Korea in the 56 industries in China. Findings Among the four driving forces, the strongest one is changes in inventories and valuables. The impact of final consumption expenditure and fixed capital formation is much lower than that of changes in inventories and valuables, but they have a broader impact for the 56 industries. This paper finds out the China’s import induction of the final demands to Korea peaked in 2005 and 2010 and decreased greatly in 2014, so the position of China as market provider for Korea will no longer rise substantially, contrarily it will be in a steady state. Originality/value First, this paper constructs the non-competitive IO table to analyze the market provider issues between two countries and provides practical ways and methods for studies on the issues of imports and market provider. Second, this paper investigates the different roles of four final demands on driving force of China as market provider for Korea and the structural changes of China as a market provider for Korea among 56 industries from 2000 to 2014.


2013 ◽  
Vol 427-429 ◽  
pp. 133-136
Author(s):  
Qiang Song ◽  
Pu Zeng

The driving theory and the dynamic characteristics of small radius steering, medium radius steering and big radius steering is analyzed, and the simulation model is established under Matlab/Simulink. Then the track bulldozers steering performance of the three sheerings is simulated. The results show that, at different steering modes, the running states of the two sides driving motors are not the same, and the track driving forces of the two sides vary widely. The track driving force is great in the small radius steering model, while small in the medium and big radius steering models. The simulation results lay the foundation for dual-motor drive track bulldozers steering performance matching.


Author(s):  
Yu. A. Taran ◽  
A. V. Kozlov ◽  
A. L. Taran

The aim of the work is to consider the mechanism of clogging the pores of the filter unit by small particles from the flow of filtrate inside them. Theoretical ideas about the process of filtering with the deposition of small particles from the filtrate on the pore walls and attribution of its fundamentals to restructuring from the original structure to the final structure allow to describe the process of clogging the pores using well studied concepts of known processes with phase transformations (in particular, crystallization). Based on this analogy and the approach to the description of the transformation of the "old" structure into a "new" one in time, using experimental data and their processing we calculated the rate of nucleation of the sediment centers (ωnucl), the linear (υlin) and volumetric rates of sediment plaques growth in the pores of the filter unit at different values of the process driving force, at different pressure difference in the system, and at different concentrations of solid particles in the suspension. Interpolation and extrapolation dependences were obtained for analyzing the mechanisms of sediments formation and growth for determining and calculating these (ωnucl, υlin) rates. Using the concepts of nonequilibrium thermodynamics to assess the influence of the driving forces we studied their influence (changes in the concentration of solid particles in the filtrate suspension and pressure drop across the filtering layer) on the dynamics of the filtration process. Using the data obtained it is possible to find the degree of clogging of through pores, which determines the filtration conditions, the filter septum type, and the filter overall dimensions.


Author(s):  
Yan Li ◽  
Shuchao Zhang ◽  
Ning Mei

In this paper, the anti-gravity flow in the spiral micro-channel on the surface of horizontal tube was visualized by the three-dimensional ultra-microscope system. The coupling relationship between the driving force and the flow was studied by Onsager reciprocal relations. The results show that the formation of the anti-gravity flow in the spiral micro-channel on the surface of horizontal tube is impacted by the combining effect of several factors, such as the capillary pressure, wettability, temperature, and bubbles.


Author(s):  
GORDON F. McEWAN

Linguistic studies have shown that the traditional idea that the expansion of the Inca Empire was the driving force behind the spread of all Quechua cannot be correct. Across much of its distribution, Quechua has far greater time-depth than can be accounted for by the short-lived Inca Empire. Linguistics likewise suggests that Aymara spread not from the south into Cuzco in the late Pre-Inca period, but also from an origin to the north. Alternative explanations must be sought for the expansion of these language families in the culture history of the Andes. Archaeological studies over the past two decades now provide a broad, generally agreed-upon outline of the cultural history of the Cuzco region. This chapter applies those findings to examine alternative possibilities for the driving forces that spread Quechua and Aymara, offering a clearer cross-disciplinary view of Andean prehistory.


Author(s):  
Kevin Morgan ◽  
Terry Marsden ◽  
Jonathan Murdoch

Chapters 1 and 2 have reviewed the contemporary theoretical and policy context of agri-food with specific reference to Europe and North America. In this chapter we turn our attention to the nature of the new agri-food geographies. What are the driving forces behind these geographies, and how do they play themselves out across time and space? This theme is central to the more detailed treatment of three different regions (Tuscany, California, and Wales) in succeeding chapters. Here, we introduce a conceptual framework that helps us to understand the new agri-food geographies. The chapter starts by outlining the nature of the conventional agri-industrial system. In general terms, we see this as a system that leads to a process of deterritorialization of foods. That is not to say that it comes without any actual geography; rather, its geographies are the result of corporate capitals’ attempts to continue to intensify and to appropriate some of the functions of agriculture in ways that stretch the links, networks, and chains between production and consumption spheres. We then place this trend in conceptual juxtaposition with the more recent forces of reterritorialization (or what some scholars term ‘relocalization’), a process whereby local and regional geographies come back again to play a central role in reshaping food production and consumption systems. We argue here that it is important to see these conflicting geographical forces as distinctive, even though both processes may indeed be operating—to varying degrees and in different ways—in the same region or locality at the same time. This is at the heart of our contingent notion of ‘worlds of food’. Throughout the twentieth century, agri-industrialism struggled with resolving Kautsky’s formulation of the agrarian question, that is, how to continue to intensify production and appropriate some farming functions in processing and agri-industry while at the same time maintaining some sort of ecological or natural balance in the agricultural transformation process (Kautsky, 1988; Goodman and Watts, 1997). In the agri-industrial model, the driving force was corporate capital.


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