The metallurgical and mechanical properties of Ti6Al4V/(WC-Co) friction welds have ben investigated. The microstructure close to the bondline comprised a mixture of acicular and equiaxed α plus β phases. The diffusion of elements in the welded specimens has been detected. The fracture strengths of Ti6Al4V/(WC-Co) friction welds markedly improved when the cobalt content in the (WC-Co) carbide su...

This paper presents the movement dynamic of the train and the relationship between the speed of wheel and train, as well as a discussion about the concept of wheel slip. There are two different operation regions designated as creep and wheelspin areas for wheel slip. Creep and wheelspin areas have stable and unstable characteristics, respectively. Wheels and rails are constructed from iron, and...

The recurrence intervals of repeating earthquakes on the San Andreas Fault in the Loma Prieta aftershock zone follow the characteristic 1/t decay of Omori’s law. A model in which these earthquakes occur on isolated patches of the fault that fail in stick-slip with creep around them can explain this observation. In this model the recurrence interval is inversely proportional to the loading rate ...

in this paper the effects of non-linearity of suspension on dynamic behavior of a railway wheelset has been studied. this wheelset has four degrees of freedom that with two constraints it has reduced to two degrees of freedom. vermeulen-johnson theory has been used to calculate contact forces between wheel and rail. in this study the creep coefficients have considered constant. any linearizatio...

T o scientists, creep refers to the very slow motion of a solid, or that of an extremely high viscous fluid, in response to an external stimulus. For creep to occur, atoms must move in a concerted or collective way. Creep motion matters in a variety of fields: In materials science, creep of grain boundaries makes it challenging to predict the longevity of material properties with potential impl...

[1] We show that realistic aftershock sequences with space-time characteristics compatible with observations are generated by a model consisting of brittle fault segments separated by creeping zones. The dynamics of the brittle regions is governed by static/kinetic friction, 3D elastic stress transfer and small creep deformation. The creeping parts are characterized by high ongoing creep veloci...