rms skew and kurtosis of surface profile height distributions: some aspects of sample variation

1980 ◽  
Vol 2 (4) ◽  
pp. 207-215 ◽  
Author(s):  
T.G. King
Wear ◽  
1982 ◽  
Vol 83 (1) ◽  
pp. 91-108 ◽  
Author(s):  
T.G. King ◽  
T.A. Spedding

2018 ◽  
Vol 12 (4) ◽  
pp. 265-269
Author(s):  
Małgorzata Poniatowska

Abstract An optimization study using the design of experiment technique is described, in which the surface profile height of a freeform surface, determined in coordinate measurements, is the response variable. The control factors are coordinate sampling parameters, i.e. the sampling grid size and the measuring tip diameter. As a result of the research, an optimal combination of these parameters was found for surface mapping with acceptable measurement uncertainty. The presented study is the first stage of optimization of machining error correction for the freeform surface and was intended to take into account mechanical-geometric filtration of surface irregularities caused by these geometrical parameters. The tests were carried out on a freeform workpiece milled with specific machining parameters, Ra of the surface roughness was 1.62 μm. The search for the optimal combination of parameters was conducted using Statistica software.


Author(s):  
Kranthi Balusu ◽  
Haiying Huang

We investigate the relationship between the average profile height and the average plastic strain of a grain in a polycrystalline material under plastic tensile strain using Crystal Plasticity Finite Element Method (CPFEM). The simulation consists of using an anisotropic grain embedded in an isotropic sample undergoing tensile plastic deformation. 150 different lattice orientations for the embedded anisotropic grain are used to represent all possible grain orientations. We found that plastic strain in the loading direction is not related to the surface profile height. However, the plastic strains in the direction normal to the surface and the transverse direction are linearly proportional to the average profile heights, irrespective of the grain orientation. The magnitude of the plastic strain in the direction normal to the surface decreases with increasing surface profile height. It is vice versa for plastic strains in the transverse direction. These results establish a possibility of determining a grain’s plastic strains from the profile height.


2019 ◽  
Vol 8 ◽  
pp. 160-167
Author(s):  
Ignat Vykhristyuk ◽  
Rodion Kulikov ◽  
Evgeny Sysoev

Methods for increasing the measurement range of the height of surface profile by the interference profilometer are proposed. The methods are based on using of multiple light sources with different wavelengths. It was shown experimentally that the measurement range increased at least 5 times due to using of two wavelengths, and at least 7 times due to using three wavelengths, while maintaining the resolution of the measurements.


2016 ◽  
Vol 44 (3) ◽  
pp. 150-173 ◽  
Author(s):  
Mehran Motamedi ◽  
Saied Taheri ◽  
Corina Sandu

ABSTRACT For tire designers, rubber friction is a topic of pronounced practical importance. Thus, development of a rubber–road contact model is of great interest. In this research, to predict the effectiveness of the tread compound in a tire as it interacts with the pavement, the physics-based multiscale rubber-friction theories developed by B. Persson and M. Klüppel were studied. The strengths of each method were identified and incorporated into a consolidated model that is more comprehensive and proficient than any single, existing, physics-based approach. In the present work, the friction coefficient was estimated for a summer tire tread compound sliding on sandpaper. The inputs to the model were the fractal properties of the rough surface and the dynamic viscoelastic modulus of rubber. The sandpaper-surface profile was measured accurately using an optical profilometer. Two-dimensional parameterization was performed using one-dimensional profile measurements. The tire tread compound was characterized via dynamic mechanical analysis. To validate the friction model, a laboratory-based, rubber-friction test that could measure the friction between a rubber sample and any arbitrary rough surface was designed and built. The apparatus consisted of a turntable, which can have the surface characteristics of choice, and a rubber wheel in contact with the turntable. The wheel speed, as well as the turntable speed, could be controlled precisely to generate the arbitrary values of longitudinal slip at which the dynamic coefficient of friction was measured. The correlation between the simulation and the experimental results was investigated.


2010 ◽  
Vol 1 (2) ◽  
pp. 116-122
Author(s):  
Sanjeev K. Gupta ◽  
Abhijit Kushari ◽  
Chandra S. Upadhyay ◽  
Comandur Venkatesan
Keyword(s):  

2020 ◽  
Vol 54 (6) ◽  
pp. 672-676
Author(s):  
L. K. Markov ◽  
I. P. Smirnova ◽  
M. V. Kukushkin ◽  
A. S. Pavluchenko

Universe ◽  
2021 ◽  
Vol 7 (6) ◽  
pp. 189
Author(s):  
Diego A. R. Dalvit ◽  
Wilton J. M. Kort-Kamp

Temporal modulation of the quantum vacuum through fast motion of a neutral body or fast changes of its optical properties is known to promote virtual into real photons, the so-called dynamical Casimir effect. Empowering modulation protocols with spatial control could enable the shaping of spectral, spatial, spin, and entanglement properties of the emitted photon pairs. Space–time quantum metasurfaces have been proposed as a platform to realize this physics via modulation of their optical properties. Here, we report the mechanical analog of this phenomenon by considering systems in which the lattice structure undergoes modulation in space and in time. We develop a microscopic theory that applies both to moving mirrors with a modulated surface profile and atomic array meta-mirrors with perturbed lattice configuration. Spatiotemporal modulation enables motion-induced generation of co- and cross-polarized photon pairs that feature frequency-linear momentum entanglement as well as vortex photon pairs featuring frequency-angular momentum entanglement. The proposed space–time dynamical Casimir effect can be interpreted as induced dynamical asymmetry in the quantum vacuum.


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