A dynamic measurement of a disc chipper cutting forces

• A cutting force measuring device is implemented on our real size chipping test bench.
• The vertical chipping force Fy is accurately measured using FRF method compensation.
• Fy has three parts: an impact, then a constant value ended by a decrease to zero.Increasing the cutting speed led to decrease Fy if the other cutting parameters are constant.

Nowadays wood chips produced from raw material of inferior quality are mainly used to feed domestic and industrial boilers. For this use, a good chip size distribution and low manufacturing energy consumption are required. Cutting forces are still inaccurately measured during the wood chipping process, which implies the use of oversized chippers' motors. A test bench for chipping wood under reasonably realistic conditions of industrial production is improved by adding an indirect force measurement system with high bandwidth of 3 KHz. The dynamic experimentations give the data needed to compute the curve presenting the vertical component of the cutting force, which is composed of three sections; the first one presents the values of the impact force; the second one is relatively straight and it refers to shear stress in wood; the third section corresponds to the period between two crosscuts.