CONTACT SIMULATION OF 3-DIMENSIONAL ROUGH SURFACES USING MOVING GRID METHOD

A new method for simulating dry contacts of three-dimensional rough su rfaces has been developed. The present work is based upon Moving Grid Method (MGM) which greatly reduces the required computer memory size. One of the major difficulties in simulating contact problems is the hu ge requirement in computer Random Access Memory (RAM). The total numbe r of nodes (N) to represent a typical three dimensional roughness topo graphy can easily be in the order of tens of thousands. To store the c orresponding deformation matrix based on conventional matrix method re quires memory size in the order of N2. The computational time necessar y to construct such a matrix is also proportional to N2. Thus a reason able solution for the three dimensional contact problem can be difficu lt to obtain. In Moving Grid Method, the required storage space for th e deformation matrix is reduced to the order of N. The computing time to construct the matrix is also proportional to N. The contact simulat ion solutions which include the asperity pressure distributions and th e corresponding deformed surface profiles were calculated. The digitiz ed surface profiles were used in the simulations. The 3-D results were compared with an existing 2-D model and the comparison showed excelle nt agreement.