Science and Education Publishing American Journal of Mechanical Engineering 2328-4110 3 1 2015 02 03 Virtual System to Simulate the Performance of Various Categories of Machine Tools during the Design Stage 7 15 EN Mounir Muhammad Koura Muhammad Lotfy Zamzam Amr Ahmed Sayed Shaaban PhD. Student in Faculty of Engineering, Ain Shams University, Egypt AJME2015312 10.12691/ajme-3-1-2 2014 12 20 2015 01 28 2015 02 03 This paper presents a simulation system designed to evaluate the static and dynamic performance of machine tools. The design considerations of the evaluation system are discussed and the system is then employed in order to compare between various categories of milling machine's structure adapted for end milling operation. The machine performance is identified in terms of static loop stiffness in both x and y directions, mode shapes, and frequency response function (FRF) at tool center point (TCP). The advantage of such a reliable model is that it could replace the many experimental tests that must otherwise be carried out each time the parameters affecting the machine tool performance are changed.