METHOD OF DETERMINING DYNAMIC COEFFICIENT OF EXTERNAL FRICTION WITH RETENTION OF SAMPLE ON INCLINED SURFACE BY ELASTIC ELEMENT Russian patent published in 2015 - IPC G01N19/02 

FIELD: testing equipment.

SUBSTANCE: two samples are used, the upper of which is placed on a flat working surface of the lower. The samples are provided with the ability of joint slope relative to the horizontal plane. In the initial position, the upper sample is attached to the elastic element located in the unloaded state, having constant stiffness in the direction of slipping off of the upper sample on an inclined surface of the lower. To determine the dynamic coefficient of external friction the samples are inclined to slipping off of the upper of them on the slope, the slope angle φ of the samples are measured at the time of slipping off, and the path l. passed by the upper sample on the working surface of the lower relative to the initial position. The dynamic coefficient of external friction is calculated by the formula $$m_{dyn}=tg\phi -\frac{l}{2L\cdot \cos \phi },$$ where L is the deformation of the vertical elastic element, defined in the calibration experiment, in free hanging of the upper sample to it.

EFFECT: simplicity of determining the dynamic coefficient of external friction, which resolves only to the experimental determining of geometrical parameters without measuring efforts.

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