Analysis Of Porosity And Temperature By Qinwu Xu - 1662 Words

Porosity and Temperature By Qinwu Xu, October 17, 2016 Introduction Metal primarily exhibits plastic and ductile behaviors in the cutting process in which its behavior is often assumed to be isotropic and homogeneous [1]. The large deformation and unconstrained plastic flow nature of machining metals can be modeled with an unstructured tetrahedral mesh, allowing for the adaptive local refinement and coarsening to alleviate mesh distortions, maintain simulation accuracy and reasonable computational performance. However, modeling of ceramic matrix composites could be much more complex due to the unique feature of this type of material: 1) the fracture and brittle behavior of materials; and b) the nonuniform distribution of porosity in the ceramic matrix. CMCs are comprised of individual layers with unique material properties dependent on fiber orientation within the polymer matrix which is typically in a woven pattern. Therefore, CMCs often exhibit anisotropic or orthotropic properties, and have lower strains and higher degrees of fragmentations than metallic materials during machining. The unique features of CMCs make simulations more challenging due to the complex nature of the problem considering material nonlinear fracture, anisotropic or orthotropic property and multi-phase interaction apart from dynamic loading and plastic deformation in machining of metals. Different modeling approaches have been studied for modeling the machining of composites and CMCs, including