描述TC11钛合金变形力学行为的新方法

DEFORMATION MECHANISM BEHAVIOR OF TC11 ALLOY WITH ARTIFICIAL NEURAL NETWORK

将人工神经网络（ＡＮＮ）理论用于建立ＴＣ１１钛合金的本构关系，意在探索出一条描述材料变形力学行为的新途径。文中给出了应用人工神经网络建立ＴＣ１１钛合金本构关系的ＢＰ模型，并在高温压缩实验的基础上，进行了流动应力的计算。计算结果与实验结果表明，二者吻合良好。因此，应用人工神经网络建立热粘塑性材料的本构关系具有重要的工程应用价值。

Artificial neural network,may simulate biological nervous system and it is referred to as parallel distributed processing.It has been proved mathematically that a three-layer network can map any function to any required accuracy.So a neural network can directly map the behaviors for the thermal viscoplastic material.By the neural network,it is unnecessary to postulate any mathematical model and identify its parameters.In this paper,a four-layer backpropagation neural network is built to acquire the constitutive relation of TC11 alloy.Temperature,effective stain,effective strain rate are used as the input vector of the neural network,the output of the neural network being the flow stress.After the network has been trained with experimental data,it can correctly reproduce the flow stress in the sampled data.Furthermore,when the network is represented with non-sampled data,it also can predict well.The results acquired from the neural network are very encouraging.