CAJ | 학술논문

　　数值模拟是研究金属切削的重要手段，但有限元方法（FEM ）由于依赖网格而存在一定的局限性，不适宜处理大变形问题。光滑粒子动力学（SPH）是一种无网格法，可以避免网格畸变，解决切削过程中材料大变形问题。结合两种方法的各自优点，建立了AISI4340钢金刚石超精密切削过程的FEM‐SPH耦合模型，研究切削过程中材料的去除机理。仿真结果表明：随着切削过程的进行工件内部应力逐渐增大，当达到屈服极限时，工件材料沿前刀面塑性流动，形成切屑，刀尖钝圆的推挤起了决定性的作用；成形表面下存在较为严重的残余应力；切削热主要来源于切削过程中塑性功的转换且大部分被切屑带走；增大刀尖钝圆半径将会使切削力尤其是切削抗力显著增大。
　　수치모의시연구금속절삭적중요수단，단유한원방법（FEM ）유우의뢰망격이존재일정적국한성，불괄의처리대변형문제。광활입자동역학（SPH）시일충무망격법，가이피면망격기변，해결절삭과정중재료대변형문제。결합량충방법적각자우점，건립료AISI4340강금강석초정밀절삭과정적FEM‐SPH우합모형，연구절삭과정중재료적거제궤리。방진결과표명：수착절삭과정적진행공건내부응력축점증대，당체도굴복겁한시，공건재료연전도면소성류동，형성절설，도첨둔원적추제기료결정성적작용；성형표면하존재교위엄중적잔여응력；절삭열주요래원우절삭과정중소성공적전환차대부분피절설대주；증대도첨둔원반경장회사절삭력우기시절삭항력현저증대。
Numerical simulation is an important approach to metal cutting process ,but finite element method (FEM ) has some limitations and can not handle large deformation problems since it′s based on mesh .Smoothed particle hydrodynamics (SPH) is a mesh‐free method and can avoid mesh distortion and hence resolve large deformation of materials in cutting .Combining the advantages of conventional FEM with the mesh‐free method ,SPH ,a FEM‐SPH coupling model for AISI4340 steel diamond ultra‐precision cutting is established and the cutting mechanism is studied . The simulation results show that :with the inner stress increasing and reaching yield stress ,the cutting layer material flows in a plastic fashion to form a chip and tool edge plays a key role in cutting ;severe residual stress is observed beneath the formed surface ; cutting heat is mainly converted from plastic work transformation and most heat is taken away by the chip ;a large edge radius will bring a great increment in cutting force ,especially in the thrust force .