Research On Aluminum Alloy Cutting Process Based On Peridynamic

Currently,numerical simulation techniques are widely used to study the mechanism of metal cutting.However,mainstream methods assume continuity and locality,limiting their ability to deal with extreme deformation,damage,and fracture issues.Therefore,this paper introduces the theory of non-local Peridynamic(PD)to solve the problem of material deformation and damage during cutting.Although PD theory is mainly used for deformation modeling of brittle materials and simple plastic materials,it is relatively blank in the field of metal cutting modeling.To address this gap,a numerical model for PD metal cutting is established by modeling the processes of elastoplastic deformation,damage and fracture,chip contact,and thermal coupling.The elastic deformation modeling decomposes Cauchy stress into deviatoric stress and hydrostatic stress and models them separately.The deviatoric stress is updated using the Jaumann rate equation based on the generalized Hooke’s law.In plastic deformation modeling,the Johnson Cook(JC)model based on the von Mises yield criterion updates the stress and strain through a radial return algorithm.The constitutive equation is introduced into the PD equation of motion using parameters such as nonlocal deformation gradients.Concerning plastic damage modeling,both physical and geometric damage models are constructed based on the JC damage model and critical tensile criterion.For tool-chip contact modeling,mesh-free theory and contact mechanics are used to construct a detection algorithm that uses the nearest distance method to reposition penetrating particles.The correction of the zero-energy mode resulting in particle aggregation at the tool tip is corrected,and a short-range force model is introduced to deal with complex deformation.Thermal-mechanical coupling modeling builds a cutting force model based on Coulomb’s friction law and meshless theory.Cutting heat calculates heat generation,and heat conduction,and a thermal stress model is built.The spatial hash algorithm optimizes the particle search form,and spatiotemporal integration is performed on the motion equation to obtain process variables at each time step.A numerical calculation program is written using C++ language.The numerical behavior of the metal deformation model is studied using a uniaxial tensile model,a KW impact model,and a thermally coupled model.Based on this,a numerical model of metal cutting is constructed,and a software interaction interface is designed using C# language.The cutting mechanism research mainly focuses on solving the extreme plastic deformation of materials and cutting damage.Firstly,the study examines the elastic-plastic deformation and process variable distribution of materials during metal cutting.Secondly,it studies the PD internal model,macroscopic shear deformation,and shear band geometry that significantly affect extreme plastic deformation and constructs the material deformation model and particle motion state model.Subsequently,the effects of different blunt circle models on the damage morphology of materials are explored using geometric and physical damage models.Finally,an orthogonal cutting experimental platform and the FEM cutting model are built to validate the model from both cutting forces and chip morphology.Based on the above research,a numerical model of PD metal cutting is established,and corresponding simulation software is developed,achieving accurate prediction of process variables,shear deformation,and damage states during chip formation.This research comprehensively models metal cutting and expands the application of PD in the field of complex deformation,contributing to shear deformation,damage state,and machining quality during the cutting process.