I have written a numerical model for calculating the elastic deformation of two elastic bodies in 3D static contact. The code takes the applied laod, Young's Modulus, Poisson ratio, and surface profile of each body. Calculates influence coefficients based on the equation provided by Love [1]. The problem is solved by conjugate gradient descent and elastic deformation is calculated by Discrete Fourier Transform- Discrete Convolution method.
I tested the model on ball-on-flat and ball-on-ball geometries with the same material properties of each body. I am facing the problem that the elastic deformation contour is diagonal instead of concentric in these cases. The pressure distribution normalized at Hertz Contact pressure and contact width is correct, but the deformation is not. I have double-checked by Kernal/influence coefficient matrix but can not seem to understand this behavior. I have attached the 3D plots of the example (ball-on-ball), the 3D plot of the influence coefficient at 1 point, and the contour of calculated deformation.
Any help, guidance to solve, or help in understanding the problem would be greatly appreciated.
Thanks.
A.E.H. Love. Stress produced in a semi-in nite solid by pressure on part of the boundary. Philosophical Transactions of the Royal Society of London, 377:54{59, 1929.