面向节能无关联平行机调度模型及分支定界法

工业企业,特别是高耗能行业,不仅要满足交货期和缩小生产周期的要求,而且不断优化能源配置,降低能耗。研究一类新的以延迟和能源消耗的加权最小为目标的生产调度问题。首先,描述问题并分析问题的复杂性。其次,建立混合整数线性规划模型。进一步,我们提出求解该问题的分支定界算法。最后,通过数值实验和数值试验,验证算法的有效性和高效性。

Machining distortion prediction of aerospace monolithic components

To predict the distortion of aerospace monolithic components, a model is established to simulate the numerical control (NC) milling process using 3D finite element method (FEM). In this model, the cutting layer is simplified firstly. Then, the models of cutting force and cutting temperature are established to gain the cutting loads, which are applied to the mesh model of the part. Finally, a prototype of machining simulation environment is developed to simulate the milling process of a spar. Key factors influencing the distortion, such as initial residual stress, cutting loads, fixture layout, cutting sequence, and tool path are considered all together. The total distortion of the spar is predicted and an experiment is conducted to validate the numerical results. It is found that the maximum discrepancy between the simulation results and experiment values is 19.0%