**Behrouz Takabi and Bruce L. Tai \***

Department of Mechanical Engineering, Texas A&M University, 3123 TAMU, College Station, TX 77843, USA; btakabi@tamu.edu

**\*** Correspondence: btai@tamu.edu; Tel.: +1-979-458-9888

Received: 6 April 2019; Accepted: 29 April 2019; Published: 2 May 2019

**Abstract:** Machining of brittle materials is common in the manufacturing industry, but few modeling techniques are available to predict materials' behavior in response to the cutting tool. The paper presents a fracture-based finite element model, named embedded cohesive zone–finite element method (ECZ–FEM). In ECZ–FEM, a network of cohesive zone (CZ) elements are embedded in the material body with regular elements to capture multiple randomized cracks during a cutting process. The CZ element is defined by the fracture energy and a scaling factor to control material ductility and chip behavior. The model is validated by an experimental study in terms of chip formation and cutting force with two different brittle materials and depths of cut. The results show that ECZ–FEM can capture various chip forms, such as dusty debris, irregular chips, and unstable crack propagation seen in the experimental cases. For the cutting force, the model can predict the relative difference among the experimental cases, but the force value is higher by 30–50%. The ECZ–FEM has demonstrated the feasibility of brittle cutting simulation with some limitations applied.

**Keywords:** orthogonal cutting; brittle materials; cohesive elements
