In the analysis of orthogonal cutting process using finite element (FE) simulations, predictions are greatly influenced by two major factors; a) flow stress characteristics of work material at cutting regimes and b) friction characteristics mainly at the tool-chip interface. The uncertainty of work material flow stress upon FE simulations may be low when there is a constitutive model for work m...

Equal channel angular pressing is the most promising method of severe plastic deformation with the capability of producing ultrafine grained materials. These materials exhibit improved mechanical and physical properties compared with their coarse grained counter parts.The temperature variation in the sample during ECA-pressing is a key factor determining the final microstructure and mechanical ...

The piston ring assembly is one of the key parts of internal combustion engine. Its performance decides engine power loss to over come friction force and determines the performance of the whole engine. As per the literature review it is reported 40 to 50 % of the total mechanical friction losses in piston ring cylinder wall interface. The present work mainly focused on study of basic tribologic...

The hydrostatic extrusion is a new method of extrusion process. The most important advantage of this method is reduction of friction and close tolerance for the coating thickness. In this study, the hydrostatic extrusion simulation of bimetallic wires has performed using of finite element method. In the following the advantages of hydrostatic extrusion compared to the direct extrusion are prese...

Metal forming processes, compared with machining ones, reduce production steps and increase manufacturing speed in addition to saving raw material. In this paper, forming process of column of a steering mechanism is investigated by finite element analyses and experimental tests; and optimum die design parameters are found. Forming process parameters including die opening angle, bearing length, ...

One of the interesting state-of-the-art approaches to welding is the process of friction stir welding (FSW). In comparison with the fusion processes, FSW is an advantageous method as it is suitable for the non-fusion weldable alloys and polymeric materials joining. Regarding the materials pure solid state joining, it also provides joints with less distortion and enhanced mechanical properties. ...

Friction and wear, often treated as unrelated, distinct phenomena, are manifestations of the same dissipative physical processes occurring at sliding interfaces. Friction force dissipates power and generates entropy. Wear irreversibly changes a material structure, often with loss of material. Associated with both friction and wear is production of irreversible entropy by interfacial dissipative...

We discuss the thermodynamics of closed quantum systems driven out of equilibrium by a change in a control parameter and undergoing a unitary process. We compare the work actually done on the system with the one that would be performed along ideal adiabatic and isothermal transformations. The comparison with the latter leads to the introduction of irreversible work, while that with the former l...

Finite element analysis based techniques are available to simulate cutting processes and offer several advantages including prediction of tool forces, distribution of stresses and temperatures, estimation of tool wear and residual stresses on machined surfaces, optimization of cutting tool geometry and cutting conditions. However, work material flow stress and friction characteristics at cuttin...

Friction in a DC servo positioning system is the main challenge to accurate positioning performance. If it can be accurately estimated, the positioning accuracy can be enhanced. Extensive research literature exists on friction modelling and estimation. The contribution of this work is a simulation-based method for estimating not only friction but also the transfer function of the system in whic...