Finite Element Modelling and Experimental Validation of the Graphite Cutting Process

Abstract

Graphite is extensively used in the engineering field due to its unique properties, and the study of its cutting mechanism has become particularly important. However, the brittle fracture mechanism of graphite makes it rather easy for cracks with a unique pattern of initiation and growth to develop when processing. Herein, the ABAQUS was selected to establish a finite element model (FEM) of the graphite cutting process. The internal crystal structure of graphite was modelled by a Voronoi structure, and a cohesion unit was globally embedded into the solid unit to simulate crack initiation and growth. In addition, the complete process of chip formation and removal was demonstrated. The analysis of the simulation results showed that the graphite material underwent three periodic cycles of material removal during the cutting process, i.e., large, tiny, and small removal stages. Meanwhile, the simulation results indicated that when ac was large enough, the crack gradually grew inside the graphite and then turned to the upper surface of the graphite. However, when ac was tiny enough, the cracks hardly expanded towards the inside of the graphite but grew upwards for a short period. Then, orthogonal cutting experiments of graphite were conducted, and the FEM was verified based on the experimental chip morphology, machined surface morphology, and current geometric model of the graphite cutting process. The simulation and experimental results were consistent. The hereby-presented FEM was a complement to simulations of the processing of brittle materials.

Influence of the shape of the toroidal flank surface on the cutting wedge angles and mechanical stresses along the drill cutting edge

“…Первая заключается в том, что модель материала должна адекватно отражать деформационное состояние при нагрузке с различной интенсивностью и направлением напряжений, приложенных к конструкции, в диапазоне рабочих условий и учитывать характер внутреннего напряжения в конструкции [12][13][14]. Вторая проблема связана с моделированием и численной реализацией изменения конфигурации режущей части в процессе формообразования в зависимости от состояния технологической системы [15,16]. Численное моделирование процессов механической обработки осложняется множественными участками контакта режущего клина с обрабатываемым материалом [17,18].…”