A Review of Elastic–Plastic Contact Mechanics

Contact mechanics of fractal surfaces by spline assisted discretisation

https://hal.archives-ouvertes.fr/hal-02348511/document

Static friction at fractal interfaces

The effect of dry metallic friction can be attributed to two major mechanisms: adhesion and ploughing. While ploughing is related to severe wear and degradation, adhesion can be connected to pure elastic deformations of the contacting bodies and is thus the predominant mechanism in a stable friction pair. The transmitted friction force is then proportional to the real area of contact. Therefore, a lot of effort has been put into the determination of the fraction of real area of contact under a given load. A broad spectrum of analytical and numerical models has been employed. However, it is quite common to employ the so-called Mindlin assumptions, where the contact area is determined by the normal load only, disregarding the influence of friction. In the subsequent tangential loading, usually the contact pressure distribution is kept fixed such that the coupling between the tangential and normal solutions is neglected. Here, a numerical solution scheme based on elastic halfspace theory for frictional contact problems is presented where full coupling between the normal and tangential tractions and displacements is taken into account. Several examples show the influence of the coupling effects, but also the limitations for the analysis of rough contacts.

Fully Coupled Frictional Contact Using Elastic Halfspace Theory

Study of thermal contact resistance of rough surfaces based on the practical topography

The present study considers finite element analysis of non-adhesive, frictionless elastic/elastic–plastic contact between a rigid flat plane and a self-affine fractal rough surface using the commercial finite element package ANSYS. Three-dimensional rough surfaces are generated using a modified two-variable Weierstrass–Mandelbrot function with given fractal parameters. Parametric studies are done to consider the general relations between contact properties and key material and surface parameters. The present analysis is validated with available experimental results in the literature. Non-dimensional contact area and displacement are obtained as functions of non-dimensional load for varying fractal surface parameters in the case of elastic contact and for varying rates of strain hardening in the case of elastic–plastic contact of fractal surfaces.

https://iopscience.iop.org/article/10.1088/0022-3727/40/14/021/pdf

Finite element contact analysis of fractal surfaces

Periampullary neoplasms are a heterogeneous group of tumors arising within 2 cm of the ampulla of Vater. Neuroendocrine tumors can originate throughout the entire body from neuroendocrine cells. These neoplasms exhibit deep differences, according to their origin and biological behavior. The synchronous presence of a primary tumor in patients affected by a neuroendocrine tumor is reported in the literature; incidence is variable and the most common site is the gastrointestinal tract. Here we report a case of 68 years old female presented with jaundice, anorexia and weight loss. She was mildly anaemic. Gall bladder was palpable. There was no organomegaly. Her CT scan and MRCP revealed a growth in periampullary region. So she underwent Whipple’s procedure. Histopathological report showed synchronous presence of periampullary carcinoma and a carcinoid tumor in stomach. As the carcinoid tumor was nonfunctioning and very small in size, it was not identified in pre-operative work up.
J Shaheed Suhrawardy Med Coll 2021; 13(2): 183-186

Niloy Ghosh

Papers

Finite element contact analysis of fractal surfaces

Periampullary Adenocarcinoma with Incidental Gastric Carcinoid Tumor: Report of an Extremely Rare Case