Finite-element Modeling and Simulation

Abstract

This chapter deals with the finite-element method (FEM) of hard machining, mainly turning (two-and three-dimensional (3D)). Results about the influence of working conditions and tool geometry (cutting-edge finishing) on tool forces, temperatures, and stresses when machining AISI 52100 steel are presented. In addition, information about residual stresses obtained through 3D FEM analysis is shown. The aim of the chapter is to demonstrate the possibilities of FEM for understanding the chip formation process in hard turning and to show its capabilities in areas like tool insert design and prediction of the surface state of the machined workpiece. First, a brief summary of the state of the art on hard machining is presented. Then FEM capabilities and limitations are shown. After that, results of process simulations will be provided and compared with those obtained in the literature. Finally, overall conclusions are pointed out and future research direction is discussed. IntroductionHard turning has become a relevant manufacturing process in producing finished components that are made of alloyed steels with hardnesses between 50 and 70 HRC [1]. The main aim of employing hard turning is avoiding the grinding operation which in most cases corresponds to the final operation for the workpiece. Comparisons between both processes show that the demanded surface roughness and ISO tolerance standards can be achieved in both processes, but higher flexibility and material removal rates can be obtained in hard turning.

Thermal load analysis and structure optimization of neutral beam injector cryosorption pump

“…If there is a high temperature heat source radiating to the cryosorption pump in the vacuum chamber, the thermal load of the cryogenic unit will be too large. Therefore, from a macro point of view, the radiation baffle of the cryosorption pump has the following requirements [1]. Firstly, it can absorb the radiant heat that is difficult to reflect off, such as the heat sink caused by the components and particles sputtering in the vacuum chamber; Secondly, the cooling structure should reflect the normal temperature radiant heat from the vacuum chamber as much as possible, and the radiant heat can be reflected in the cooling process.…”