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摘要：
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采用等温恒应变速率压缩实验研究,揭示了TA15钛合金热变形过程中变形温度、应变速率和应变对流动应力的影响规律。利用逐步回归法确定了影响流动应力的宏观可测变量(变形温度、应变速率和应变)的"最优"自变量子集,基于热压缩实验数据和部分神经网络预测数据,利用最小二乘估计算法求解模型回归参数值,建立了基于逐步回归法的TA15的材料本构模型。实验值与回归计算值的对比表明:所建立的材料本构模型描述TA15钛合金的热变形过程中所发生的动态软化过程(动态再结晶和动态回复)是合理可行的,且所建的材料本构模型形式简单,方便于应用到商用有限元软件所提供接口子程序中。
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Based on the hot compression experimental study at isothermal constant strain rate,the influence of deformation temperature,strain rate and strain on flow stress were acquired in hot deformation process of TA15 titanium alloy.The "optimum" independent variable subsets of macro-variables testable(deformation temperature、strain rate and strain) influencing the flow stress were determined by using stepwise regression method.Then,based on experiment data and some ANN prediction data,TA15 constitutive model was constructed using stepwise regression method,and the regression coefficients of which were calculated using least squares method.The comparison between experiments and computations shows that the constructed material constitutive models are sound and feasible in describing dynamic softening process(dynamic recrystallization and dynamic recovery) of TA15 titanium alloy in hot deformation process,and they are simple in form and can be conveniently used in interface subroutine program.
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基金项目：
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国家自然基金重点项目(50735005);;
国家“863”(2006AA04Z135)资助项目
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作者简介：
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参考文献：
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