EXPERIMENTAL MEASUREMENTS OF FRICTION IN DESIGNING AXISYMMETRIC WORKPIECES OF LAMINATED WOOD

This paper presents the procedure and the results of experimental measurements of friction forces, which arise as a result of the resistance to movement of veneer over curved contact surface of tool-shapers during the forming process of axisymmetric workpieces made from laminated wood. Friction forces are measured in three-point zone located on the lower contact surface of the tool. Material used for coating the tool is aluminum sheet 2 mm thick, the usual quality for this purpose. The model of the workpiece is axisymmetrical, whose structure is formed with cross-laid sheets of peeled beech veneer with thickness of 1.5mm, while the bottom-contact list has a vertically oriented fibers in relation to the direction of motion over the contact surface of the tool. Experimental measurements are performed in realistic conditions of production in order to determine the effect of friction value, as one of the independent input parameters, on the output value of the pressing force.