Serviceable engineering components not only rely on their bulk material properties but also on the design and the characteristics of their surface. These characteristics influence directly the surface quality of the machined products. In terms of surface roughness, the influence of the tool material can be also caused by its tribological properties, i.e. a contact behavior between cutting tool and workpiece. This study presents a formulation of the nominal’s coefficient and friction forces generated in machining between workpiece and cutting tool using cutting force profiles. The obtained equations led to the evaluation of coefficient, frictional forces and cutting inserts characterization in terms of better surface finish and lowest frictional forces. Indeed, results show that the contact between cutting tool and workpiece depends on the materials cutting tool nature, and that the cutting tool type can influences the surface roughness of the machined surface.
The linear governing equations of a micropolar thermoelastic medium without energy dissipation are solved for surface wave solutions. The appropriate solutions satisfying the radiation conditions are applied to the required boundary conditions at the free surface of the half-space of the medium. A frequency equation is obtained for Rayleigh wave in the medium. The non-dimensional speed of the propagation of Rayleigh wave is computed for a specific model of the material and are shown graphically against frequency and non-dimensional parameter.
This article provides a method of acoustic emission (AE) technique to detect leakage in pipeline and locate the position of the leakage. The AE sensor is made of piezoelectric effect transducer to pick up the acoustic emission signal which is generated from the turbulent flow at the leak position. The signal conditioning unit is used to enhanced and eliminate the background noise from the leak location sources. The main acoustic emission processing unit is used to acquire and process the extracted AE characteristic parameters from preprocessing waveform. The leak pipeline is simulated by drilling the hole and plugged with M8 screw at different locations. The results show that the proposed AE method can detect and locate simultaneous leak condition in pipeline with promising results.
This paper presents an analytical and a numerical thermomechanical investigation of a thick-walled cylinder made of the functionally graded materials (FGMs). The hollow cylinder is subjected to a pressure and a thermal load and the properties of this material are varying across the thickness from the inner face that is a ceramic to the outer one which is a metal. After validating the current results by the analytical results, the thermomechanical behavior of the cylinder in the transient condition is investigated and the hoop and radial stresses and also temperature distribution are reported. The results reveal that the use of FG material causes a decrease in the stress; thus, it significantly improves thermomechanical behavior of the domain, thanks to using FG materials.