Apparatus and method for determining coefficients of friction

摘要

A microprocessor or computer controlled interactive apparatus to compute coefficients of static and kinetic friction for a test surface using acceleration data of a weighted test block sliding over a test surface. The transient action of the block is damped linear harmonic and is generated by a microprocessor-controlled stepper motor and micrometer connected to the block with two springs. The apparatus provides an accessible graphical display of the recorded acceleration data which comprises a series of relative time values and associated block acceleration values. A movable cursor permits the user to interactively select the point on the surface for which the coefficient of kinetic friction is to be computed. The computed coefficient is then displayed on the graphics display device with the acceleration plot. The cursor may then be redisplayed and moved horizontally with respect to the graphical plot of the acceleration data so that another coefficient of kinetic friction may be computed and displayed for a different selected point. The coefficient of static friction is determined by the amount of elongation of the spring required before the test block breaks free of the static friction and slides over the surface.