Search results for "Waviness"
showing 5 items of 5 documents
Surface Integrity
2008
This chapter provides comprehensive knowledge regarding the state and properties of both surface and subsurface layers generated during machining processes, including different associated mechanical and thermal influences. Basic models of the superficial layer and factors effecting surface integrity are presented. Decomposition of surface topography into roughness, waviness and form along with appropriate filtering methods is outlined. The characterization of surface roughness based on 2D and 3D roughness parameters as well as motif, fractal and frequency characteristics are presented. In particular, all standardized areal surface parameters are specified, and practical examples are provide…
Cutting Vibrations
2008
Chapter 8 provides comprehensive engineering knowledge regarding cutting vibrations, their typical sources in machining operations, and methods of their elimination to prevent negative influence on the surface finish (chatter marks). The classification of cutting vibrations including free, forced, and self-excited vibrations is discussed, and all possible sources and mechanisms of all types of cutting vibrations are specified and characterized. The regeneration of surface waviness, which is the predominant mechanism of chatter, is outlined for turning and milling operations. The stability of machining operations based on the stability lobe diagrams is highlighted and their practical applica…
Numerical model for the characterization of biocomposites reinforced by sisal fibres
2018
Abstract Although several works have been recently published in literature about biocomposites, i.e. on innovative and ecofriendly polymer matrix composites reinforced by natural fibers, there are not studies on the influence of the waviness that various natural fiber present after their extraction. In order to give a contribution to the knowledge of the effects of the fiber waviness on the main mechanical properties of biocomposites, as the longitudinal Young modulus, in the present study a systematic numerical analysis has been carried out by using parametric models properly developed, that let the user to consider the effects of the key influence parameters as the fiber concentrations an…
Parameters influencing the stiffness of composites reinforced by carbon nanotubes – A numerical–analytical approach
2014
Abstract Due to their high stiffness and strength, as well as their electrical conductivity, carbon nanotubes are under intense investigation as fillers in polymer matrix composites. The nature of the carbon nanotube/polymer bonding and the curvature of the carbon nanotubes may strongly reduce the reinforcing effect of the carbon nanotubes when added to a matrix to create composites. Here the effects of carbon nanotube waviness and the interaction with the matrix on the stiffness of the composite are investigated. Using a mixed numerical–analytical model, a parametric study of the waviness and volume fraction influence of CNTs on the elastic behavior of the nanocomposite is presented. The m…
3D displacement field measurement with correlation based on the micro-geometrical surface texture
2011
Image correlation methods are widely used in experimental mechanics to obtain displacement field measurements. Currently, these methods are applied using digital images of the initial and deformed surfaces sprayed with black or white paint. Speckle patterns are then captured and the correlation is performed with a high degree of accuracy to an order of 0.01 pixels. In 3D, however, stereo-correlation leads to a lower degree of accuracy. Correlation techniques are based on the search for a sub-image (or pattern) displacement field. The work presented in this paper introduces a new correlation-based approach for 3D displacement field measurement that uses an additional 3D laser scanner and a C…