Out-line Prediction Of NC Machining Errors In Low-rigid Parts

Due to the thin-walled and slim structures or the low modulus of elasticity, thedeformation errors are produced by the cutting forces in the process of cutting, whichaffects the machining precision and quality of the low-stiffness parts. Because of thelow stiffness, the machining error produced by the cutting forces is the biggest oneamong all errors, therefore the cutting force is the key factor to result in machiningerrors. The deformation errors in the NC machining of the low-stiffness parts arestudied in the paper. According to the predicted errors, one may make a compensationof the cutter path of machine tools by CNC programming in advance and improve theprocessing quality and efficiency.Based on both the cutting force-feeding model from the cutting principle and thecutting force-deformation model from structural mechanics of parts,, a mathematicaliterative algorithm of machining errors is established. Aimed at processing of shaftparts, flat thin-wall parts and curved thin-walled parts, the analytically iterativealgorithm and the finite element iteration algorithm are used to calculate thedeformation errors. The convergence and reliability of the iterative algorithm arevalidated in all examples, which shows fast convergence and high calculationefficiency of the iterative algorithm. Compared with the exact solutions and theexperimental results in literature, this algorithm shows high precision.The ANSYS finite element software is the main analytical tool in this paper. Theusage of the software for machining errors is introduced in detail. Using its modelingfunction one directly generates model and the finite element mesh. Some key steps,such as the choose of elements, the treatment of loads and boundary conditions, thefetch and display of calculation results, are discussed. This work provides a samplehow to use the present theoretical model in engineering practice...