Application of multi-scale areal curvature analysis to contact problem

Author(s):  
T Bartkowiak ◽  
R Staniek
Procedia CIRP ◽  
2014 ◽  
Vol 13 ◽  
pp. 308-313 ◽  
Author(s):  
Margot Vulliez ◽  
Matthew A. Gleason ◽  
Aurélien Souto-Lebel ◽  
Yann Quinsat ◽  
Claire Lartigue ◽  
...  

2016 ◽  
Vol 36 (1) ◽  
pp. 44-50 ◽  
Author(s):  
Tomasz Bartkowiak ◽  
Christopher Brown

Abstract This paper demonstrates the use of multi-scale curvature analysis, an areal new surface characterization technique for better understanding topographies, for analyzing surfaces created by conventional machining and grinding. Curvature, like slope and area, changes with scale of observation, or calculation, on irregular surfaces, therefore it can be used for multi-scale geometric analysis. Curvatures on a surface should be indicative of topographically dependent behavior of a surface and curvatures are, in turn, influenced by the processing and use of the surface. Curvatures have not been well characterized previously. Curvature has been used for calculations in contact mechanics and for the evaluation of cutting edges. In the current work two parts were machined and then one of them was ground. The surface topographies were measured with a scanning laser confocal microscope. Plots of curvatures as a function of position and scale are presented, and the means and standard deviations of principal curvatures are plotted as a function of scale. Statistical analyses show the relations between curvature and these two manufacturing processes at multiple scales.


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3864
Author(s):  
Nolan Ryan Chu ◽  
Robert L. Jackson ◽  
Xianzhang Wang ◽  
Arup Gangopadhyay ◽  
Hamed Ghaednia

The solution to an elastic-plastic rough surface contact problem can be applied to phenomena such as friction and contact resistance. Many different types of models have therefore been developed to solve rough surface contact. A deterministic approach may accurately describe the entire surface, but the computing time is too long for practical use. Thus, mathematically abbreviated models have been developed to describe rough surface contact. Many popular models employ a statistical methodology to solve the contact problem, and they borrow the solution for spherical or parabolic contact to represent individual asperities. However, it is believed that a sinusoidal geometry may be a more realistic asperity representation. This has been applied to a newer version of the stacked multiscale model and statistical models. While no single model can accurately describe every contact problem better than any other, this work aims to help establish guidelines that determine the best model to solve a rough surface contact problem by applying mathematical and deterministic models to two reference surfaces in contact with a rigid flat. The discrepancies and similarities form the basis of those guidelines.


Author(s):  
H. Boffy ◽  
M. C. Baietto ◽  
P. Sainsot ◽  
T. Lubrecht

The actual contact between solid surfaces is generally rough and time dependent. The stresses induced by the rough contact can only be correctly described using a detailed 3D model. Even finer details are required in the case of surface coatings. Consequently, the rough coated contact problem is strongly multi-scale: the characteristic dimensions of the contact, the coating and the roughness range from the millimeter to the nanometer. A straightforward discretisation of this multi-scale problem would exceed the memory and CPU capacity of current (and next generation) computers. This paper proposes an efficient numerical model that can handle this multi-scale problem: using 109 points and locally refined grids. The proposed model is based on multigrid techniques within a finite difference frame work. Localised refinement is implemented to optimize memory requirement and computing time. Validation of the solver is performed through a comparison with analytical results for simple cases. The algorithm performance is analyzed through a parametric study describing the influence of layer thickness (0.01 < t/a < 10) and mechanical properties (0.005 < Ec/Es < 10) of the coating on the contact parameters (Ph, a). A linear graded coating, used as a solution to avoid interfacial problems, is then compared to a coating with constant properties. A quantitative analysis of the evolution of the maximum tensile stress with depth is conducted in both cases.


2016 ◽  
Vol 136 (8) ◽  
pp. 1078-1084
Author(s):  
Shoichi Takei ◽  
Shuichi Akizuki ◽  
Manabu Hashimoto

2014 ◽  
Vol 2014 (2) ◽  
pp. 60-71
Author(s):  
Peyman Mohammadmoradi ◽  
◽  
Mohammad Rasaeii ◽  

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