Constitutive Model of TB15 Titanium Alloy Based on Physics and Meta-modeling
The Gleeble-3800 thermal simulator was used to conduct isothermal constant strain rate thermal compression tests on TB15 titanium alloy to study its thermal deformation behavior under deformation temperatures of 810-930 ℃,strain rate of 0.001-10-s-1 and height depression of 60％;three constitutive relationship models,including physics,support vector regression(SVR)and response surface,were developed to predict the flow stresses of TB15 titanium alloy and the prediction accuracy of the three constitutive models was compared.The results show that the flow stress of TB15 titanium alloy decreases with the decrease in the strain rate and the increase in deformation temperature,and the change of peak stress is more sensitive to the strain rate;the correlation coefficient R of physics,SVR and response surface constitutive models is all greater than 0.98,but the R value of response surface constitutive model reaches 0.993,and the frequency of the relative error of the response surface constitutive models±5％of the predicted value reaches 67.9％,which is greater than that of the physics constitutive model(58.6％).The significance test value P＜0.0001 of the constructed response surface constitutive model is also obtained by ANOVA,indicating that the regression relationship of the flow stress predicted by the response surface constitutive model with the deformation temperature,strain rate and strain is significant and has higher accuracy than the physics and SVR constitutive models,which can better predict the flow stress of TB15 titanium alloy.
TB15 titanium alloyconstitutive modelresponse surfacesignificance test value
NETL
NSTL
万方数据
