Prediction and Analysis of Cutting Forces Including the Effect of Tool Runout During End Milling

In this study, a cutting force model is presented, which includes the effects of tool runout to predict cutting forces in end milling. In the model, the end mill is separated into a series of disc elements along its axis to reflect the effect of the helix angle. The cutting forces are predicted at each time interval with a mechanistic model in which the force coefficients are defined as the exponential functions of the average chip thickness. The effect of tool runout on chip load is considered based on the true path of the flutes. An in-depth analysis indicates that tool runout shifts the cutting force pattern from the tooth passing frequency to the spindle rotational one. This model is also validated with the comparison of experimental cutting forces available in the literature with those from simulation for aluminum alloy Al7075-T6, and provides a satisfactory prediction of cutting forces.