scholarly journals Contact problem on indentation of an elastic half-plane with functionally-graded coating in presence of tangential stresses on the surface

2018 ◽  
Vol 226 ◽  
pp. 03018 ◽  
Author(s):  
Sergei S. Volkov ◽  
Andrey S. Vasiliev ◽  
Evgeniy V. Sadyrin
Keyword(s):  
Fourier Series ◽  
Contact Problem ◽  
Half Plane ◽  
Contact Area ◽  
Functionally Graded ◽  
Dual Integral Equations ◽  
Normal Contact ◽  
Functionally Graded Coating ◽  
Tangential Stresses ◽  
Graded Coating

Plane contact problem on indentation of an elastic half-plane with functionally graded coating by a parabolic punch is considered. The surface of the half-plane is additionally subjected to distributed tangential stresses in a certain region different from contact area. The contact area is assumed to be asymmetric with respect to the center of the punch. Tangential stresses are represented in the form of Fourier series. The problem is reduced to the solution of two dual integral equations over even and odd functions describing distribution of normal contact stresses. The bilateral asymptotic method is used to solve these equations. Approximated analytical solutions asymptotically exact for both the small and large values of relative coating thickness are constructed.

Fretting contact with finite friction of a functionally graded coating with arbitrarily varying elastic modulus Part 1: Normal loading

2007 ◽  
Vol 42 (5) ◽  
pp. 293-304 ◽  
Author(s):  
L-L Ke ◽  
Y-S Wang
Keyword(s):  
Shear Modulus ◽  
Poisson’S Ratio ◽  
Contact Region ◽  
Functionally Graded ◽  
Poisson's Ratio ◽  
Contact Damage ◽  
Normal Contact ◽  
Functionally Graded Coating ◽  
Graded Coating ◽  
Contact Surfaces

The two-dimensional normal contact of a functionally graded coated half-space by a rigid cylindrical punch under the action of a monotonically increasing normal load is considered. Friction with a finite coefficient is assumed between the contact surfaces. The whole contact region is composed of an inner stick region and two outer slip regions. The linear multilayered model is used to model functionally graded materials (FGMs) with arbitrarily varying shear modulus and constant Poisson's ratio under plane strain deformation, i.e. the FGM is divided into several sublayers and in each sublayer the shear modulus is assumed to be a linear function while Poisson's ratio is a constant. With the use of the transfer matrix method and Fourier integral transform technique, the problem is reduced to a set of Cauchy singular integral equations. An iterative method is developed to determine the stick-slip region. Normal and tangential tractions in the whole contact region are calculated. It is found that the stick region depends on the gradient of the functionally graded coating as well as on Poisson's ratio and the friction coefficient. The results also show that appropriate gradual variation in the shear modulus can significantly alter the contact traction. This may lead to suppression of Hertzian cracking at the edges of the contact region and thus modify the contact damage. Therefore, it is believed that FGM coatings would have potential applications in improving the resistance to contact damage at the contact surfaces.

Development of Functionally Graded Coating by Thermal Spray Deposition

2015 ◽  
pp. 121-162
Author(s):  
Jyotsna Dutta Majumdar ◽  
Indranil Manna
Keyword(s):  
Thermal Spray ◽  
Spray Deposition ◽  
Thermal Spraying ◽  
Chemical Vapor ◽  
Solid Substrate ◽  
Functionally Graded ◽  
Functionally Graded Coating ◽  
Energy Applications ◽  
Graded Coating ◽  
Gradient Coatings

Functionally Gradient Coatings (FGCs) are emerging materials with an improved service life and have a promising future for the production of (a) tailored components for applications subjected to large thermal gradients, (b) smart coating with improved corrosion and wear resistance, (c) improved fatigue wear, and (d) improved material structures for energy applications like batteries, fuel cells, etc. FGCs may be developed by physical/chemical vapor deposition, electro/electroless deposition, thermal spray deposition technique, etc. Thermal spraying refers to the technique or a group of techniques whereby molten or semi-molten droplets of materials are sprayed onto a solid substrate to develop the coating. In this chapter, detailed overviews of the development of functionally graded coating by thermal spray deposition techniques are presented. In addition, a few research results on the development of functionally graded coating for tribological and thermal barrier applications are presented.

Analysis on Functionally Graded Material Coating Interface Crack

2012 ◽  
Vol 602-604 ◽  
pp. 1596-1599
Author(s):  
Bo He ◽  
Chang Qing Sun
Keyword(s):  
Elastic Modulus ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Interface Crack ◽  
Functionally Graded ◽  
Physical Parameters ◽  
Mode I ◽  
Modulus Ratio ◽  
Functionally Graded Coating ◽  
Graded Coating

It is assumed that the physical parameters of functionally graded coating material accords with the variation of degree n polynomial, and based on this material model, the behavior of crack fracture on the interface of functionally graded coating is studied. The results show that when the functionally graded coating structure bears a tension load, stress intensity factors of mode I and mode II exist at the same time generally, and the intensity factor of mode I occupies a leading position all along. Besides, when the elastic modulus ratio of the base to the functionally graded coating top is 5 and the elastic modulus of functionally graded coating varies linearly, the stress intensity factor of interface crack is the smallest, and with the increasing of elastic modulus ratio, the optimal non-uniform parameter tends to be larger than 1.

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