Prying Action in a Bolted Cantilever Analyzed as a Receding Contact Problem

2019 ◽  
Vol 145 (4) ◽  
pp. 04019018 ◽  
Author(s):  
Dan Hu ◽  
Jim Papadopoulos ◽  
George G. Adams
Keyword(s):  
Contact Problem ◽  
Prying Action ◽  
Receding Contact

A semianalytical and finite-element solution to the unbonded contact between a frictionless layer and an FGM-coated half-plane

2017 ◽  
Vol 24 (2) ◽  
pp. 448-464 ◽  
Author(s):  
Jie Yan ◽  
Changwen Mi ◽  
Zhixin Liu
Keyword(s):  
Integral Equation ◽  
Finite Element ◽  
Singular Integral Equation ◽  
Contact Problem ◽  
Singular Integral ◽  
Material Properties ◽  
Elastic Layer ◽  
Coated Substrate ◽  
Receding Contact ◽  
Contact Size

In this work, we examine the receding contact between a homogeneous elastic layer and a half-plane substrate reinforced by a functionally graded coating. The material properties of the coating are allowed to vary exponentially along its thickness. A distributed traction load applied over a finite segment of the layer surface presses the layer and the coated substrate against each other. It is further assumed that the receding contact between the layer and the coated substrate is frictionless. In the absence of body forces, Fourier integral transforms are used to convert the governing equations and boundary conditions of the plane receding contact problem into a singular integral equation with the contact pressure and contact size as unknowns. Gauss–Chebyshev quadrature is subsequently employed to discretize both the singular integral equation and the force equilibrium condition at the contact interface. An iterative algorithm based on the method of steepest descent has been proposed to numerically solve the system of algebraic equations, which is linear for the contact pressure but nonlinear for the contact size. Extensive case studies are performed with respect to the coating inhomogeneity parameter, geometric parameters, material properties, and the extent of the indentation load. As a result of the indentation, the elastic layer remains in contact with the coated substrate over only a finite interval. Exterior to this region, the layer and the coated substrate lose contact. Nonetheless, the receding contact size is always larger than that of the indentation traction. To validate the theoretical solution, we have also developed a finite-element model to solve the same receding contact problem. Numerical results of finite-element modeling and theoretical development are compared in detail for a number of parametric studies and are found to agree very well with each other.

On the receding contact between a graded and a homogeneous layer due to a flat-ended indenter

2021 ◽  
pp. 108128652110431
Author(s):  
Rui Cao ◽  
Changwen Mi
Keyword(s):  
Finite Element ◽  
Contact Problem ◽  
Integral Equations ◽  
Singular Integral ◽  
Functional Dependence ◽  
Singular Integral Equations ◽  
Homogeneous Layer ◽  
Cauchy Type ◽  
Receding Contact ◽  
Contact Pressures

This paper solves the frictionless receding contact problem between a graded and a homogeneous elastic layer due to a flat-ended rigid indenter. Although its Poisson’s ratio is kept as a constant, the shear modulus in the graded layer is assumed to exponentially vary along the thickness direction. The primary goal of this study is to investigate the functional dependence of both contact pressures and the extent of receding contact on the mechanical and geometric properties. For verification and validation purposes, both theoretical analysis and finite element modelings are conducted. In the analytical formulation, governing equations and boundary conditions of the double contact problem are converted into dual singular integral equations of Cauchy type with the help of Fourier integral transforms. In view of the drastically different singularity behavior of the stationary and receding contact pressures, Gauss–Chebyshev quadratures and collocations of both the first and the second kinds have to be jointly used to transform the dual singular integral equations into an algebraic system. As the resultant algebraic equations are nonlinear with respect to the extent of receding contact, an iterative algorithm based on the method of steepest descent is further developed. The semianalytical results are extensively verified and validated with those obtained from the graded finite element method, whose implementation details are also given for easy reference. Results from both approaches reveal that the property gradation, indenter width, and thickness ratio all play significant roles in the determination of both contact pressures and the receding contact extent. An appropriate combination of these parameters is able to tailor the double contact properties as desired.

scholarly journals Finite Element Modeling of Receding Contact Problem

2019 ◽  
Vol 11 (4) ◽  
pp. 468-475
Author(s):  
Murat Yaylacı ◽  
Mehmet Çağrı Bayrak ◽  
Mehmet Avcar
Keyword(s):  
Finite Element ◽  
Contact Problem ◽  
Finite Element Modeling ◽  
Element Modeling ◽  
Receding Contact

Double frictional receding contact problem for an orthotropic layer loaded by normal and tangential forces

Meccanica ◽  
2019 ◽  
Vol 54 (14) ◽  
pp. 2183-2206 ◽  
Author(s):  
B. Yildirim ◽  
K. B. Yilmaz ◽  
I. Comez ◽  
M. A. Guler
Keyword(s):  
Contact Problem ◽  
Orthotropic Layer ◽  
Tangential Forces ◽  
Receding Contact

Unbonded Contact of a Square Plate on an Elastic Half-Space or a Winkler Foundation

1988 ◽  
Vol 55 (2) ◽  
pp. 430-436 ◽  
Author(s):  
Hui Li ◽  
J. P. Dempsey
Keyword(s):  
Contact Problem ◽  
Half Space ◽  
Contact Region ◽  
Elastic Half Space ◽  
Unilateral Contact ◽  
Winkler Foundation ◽  
Vertical Loading ◽  
Centrally Symmetric ◽  
Receding Contact ◽  
Square Plate

The unbonded frictionless receding contact problem of a thin plate placed under centrally symmetric vertical loading while resting on an elastic half-space or a Winkler foundation is solved in this paper. The problem is transformed into the solution of two-coupled integral-series equations over an unknown contact region. The problem is nonlinear by virtue of unilateral contact and therefore needs to be solved iteratively. Special attention is given to the edge and corner contact pressure singularities for the plate on the elastic half-space. Comparison is made with other relevant numerical results available.

A Rigid Punch on an Elastic Half-Space Under the Effect of Friction: A Finite Difference Solution

2008 ◽  
Author(s):  
Avraham Dorogoy ◽  
Leslie Banks-Sills
Keyword(s):  
Finite Difference ◽  
Contact Problem ◽  
Half Space ◽  
Contact Zone ◽  
Contact Problems ◽  
Elastic Half Space ◽  
Rigid Punch ◽  
Normal Loading ◽  
Receding Contact ◽  
Stationary Contact

The accuracy of the finite difference technique in solving frictionless and frictional advancing contact problems is investigated by solving the problem of a rigid punch on an elastic halfspace subjected to normal loading. Stick and slip conditions between the elastic and the rigid materials are added to an existing numerical algorithm which was previously used for solving frictionless and frictional stationary and receding contact problems. The numerical additions are first tested by applying them in the solution of receding and stationary contact problems and comparing them to known solutions. The receding contact problem is that of an elastic slab on a rigid half-plane; the stationary contact problem is that of a flat rigid punch on an elastic half-space. In both cases the influence of friction is examined. The results are compared to those of other investigations with very good agreement observed. Once more it is verified that for both receding and stationary contact, load steps are not required for obtaining a solution if the loads are applied monotonically, whether or not there is friction. Next, an advancing contact problem of a round rigid punch on an elastic half-space subjected to normal loading, with and without the influence of friction is investigated. The results for frictionless advancing contact, which are obtained without load steps, are compared to analytical results, namely the Hertz problem; excellent agreement is observed. When friction is present, load steps and iterations for determining the contact area within each load step, are required. Hence, the existing code, in which only iterations to determine the contact zone were employed, was modified to include load steps, together with the above mentioned iterations for each load step. The effect of friction on the stress distribution and contact length is studied. It is found that when stick conditions appear in the contact zone, an increase in the friction coefficient results in an increase in the stick zone size within the contact zone. These results agree well with semianalytical results of another investigation, illustrating the accuracy and capabilities of the finite difference technique for advancing contact.

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