论文标题
通过机器学习加速基于相位的模拟
Accelerating phase-field-based simulation via machine learning
论文作者
论文摘要
基于相位的模型已在材料科学,机械,物理学,生物学,化学和工程中变得普遍,以模拟微观结构的演变。但是,当应用于大型复杂系统时,它们的弊端非常昂贵。为了降低这种计算成本,在当前工作中开发了一个基于联合国性的人工神经网络作为替代模型。该网络的训练输入是从基于晶粒微观结构演化的Fan-Chen模型的初始 - 接壤问题问题(IBVP)的数值解决方案的结果中获得的。特别是,进行了大约250个具有不同初始阶参数的不同模拟,并为每个模拟存储了相位场的时间演变的200帧。该网络接受了90%的数据训练,以模拟的$ i $ th帧,即订单参数字段,作为输入,并生产$(i+1)$ - 第三帧作为输出。网络的评估是使用由2200个微观结构组成的测试数据集进行的,基于与最初用于培训不同的配置。训练有素的网络递归地应用于初始订单参数,以计算相场的时间演变。将结果与从常规数值解决方案获得的误差和系统自由能从常规数值解决方案中获得的结果进行了比较。在所有点上平均的结果订单参数误差为0.005,在所有模拟框中,总自由能的相对误差不超过1%。
Phase-field-based models have become common in material science, mechanics, physics, biology, chemistry, and engineering for the simulation of microstructure evolution. Yet, they suffer from the drawback of being computationally very costly when applied to large, complex systems. To reduce such computational costs, a Unet-based artificial neural network is developed as a surrogate model in the current work. Training input for this network is obtained from the results of the numerical solution of initial-boundary-value problems (IBVPs) based on the Fan-Chen model for grain microstructure evolution. In particular, about 250 different simulations with varying initial order parameters are carried out and 200 frames of the time evolution of the phase fields are stored for each simulation. The network is trained with 90% of this data, taking the $i$-th frame of a simulation, i.e. order parameter field, as input, and producing the $(i+1)$-th frame as the output. Evaluation of the network is carried out with a test dataset consisting of 2200 microstructures based on different configurations than originally used for training. The trained network is applied recursively on initial order parameters to calculate the time evolution of the phase fields. The results are compared to the ones obtained from the conventional numerical solution in terms of the errors in order parameters and the system's free energy. The resulting order parameter error averaged over all points and all simulation cases is 0.005 and the relative error in the total free energy in all simulation boxes does not exceed 1%.