Thermal-mechanical coupling model-based workpiece surface residual stress control and adjustment method

Abstract

The invention discloses a thermal-mechanical coupling model-based workpiece surface residual stress control and adjustment method. The method includes the following steps that: a, a cutting test is performed, surface residual stress sigmai correspondingly obtained under each group of cutting parameters is measured, wherein the cutting parameters include cutting depths ap, cutting speeds V and feedquantities f; b, an orthogonal cutting force prediction model is constructed based on an Oxley prediction model and a J-C constitutive model; c, a workpiece temperature prediction model is constructed based on thermal stress formed by means of the superposition of the temperature of a shearing zone and a ploughing and cutting zone; d, a thermal-mechanical coupling-based workpiece surface residualstress empirical model is constructed based on the orthogonal cutting force prediction model and the workpiece temperature prediction model, and an expectation function is selected to describe the influence of each parameter; and e, the sum of the absolute values of the difference values of observed surface residual stress sigmai and predicted residual stress sigmasurface is adopted as a fitnessfunction, and a genetic algorithm is used to perform optimization, so that a proportional coefficient and an exponential coefficient can be obtained. The method of the invention has the advantages ofshort calculation time and convenient use.

Description

technical field [0001] The invention relates to the technical field of mechanical processing, in particular to a method for controlling residual stress on the surface of a workpiece based on a thermal-mechanical coupling model. Background technique [0002] The residual stress existing in the surface layer is an important aspect of the surface integrity that affects the fatigue life and corrosion resistance of mechanical parts. As the last processing procedure of many parts, the machining process has an important influence on the surface residual stress of the parts. In recent years, a lot of research has been done on the measurement and prediction of machining residual stress at home and abroad, and the machining residual stress is often considered to be a function of machining parameters. However, the joint action of thermal load and mechanical load directly affects the stress field during cutting. On the other hand, in most empirical forecasting models, some form of mon...

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Problems solved by technology

At present, the factors affecting the residual stress on the surface have taken into account the effects of thermal and mechanical forces, but there are long operating periods, many experimental equipment, and complicated experimental conditions. There are only advantages in the prediction model, so it cannot be well understood. For regulation and optimization of residual stress

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