*Article* **Discrete Element Simulation of Orthogonal Machining of Soda-Lime Glass with Seed Cracks**

**Guang Yang, Hazem Alkotami and Shuting Lei \***

Department of Industrial and Manufacturing Systems Engineering, Kansas State University, Manhattan, KS 66506, USA; gyang@ksu.edu (G.Y.); alkotami@ksu.edu (H.A.)

**\*** Correspondence: lei@ksu.edu; Tel.: +1-785-532-3731

Received: 30 December 2019; Accepted: 13 January 2020; Published: 16 January 2020

**Abstract:** Demands for producing high quality glass components have been increasing due to their superior mechanical and optical properties. However, due to their high hardness and brittleness, they present great challenges to researchers when developing new machining processes. In this work, the discrete element method (DEM) is used to simulate orthogonal machining of synthetic soda-lime glass workpieces that are created using a bonded particle model and installed with four different types of seed cracks. The effects of these seed cracks on machining performance are studied and predicted through the DEM simulation. It is found that cutting force, random cracks, and surface roughness are reduced by up to 90%, 74%, and 47%, respectively, for the workpieces with seed cracks compared to the regular ones. The results show that high performance machining through DEM simulation can be achieved with optimal seed cracks.

**Keywords:** discrete element method; orthogonal cutting; seed cracks; surface roughness
