关键词: 有限元, 升温速率, 对流换热系数, 温度场, 残余应力, 复合材料

Abstract: Based on the time-dependent properties of the composite materials, a three-dimensional thermal-mechanical-chemical multi-field coupling model for thermal curing of resin matrix composites was established. The variation characteristics of temperature, curing degree and residual stress during the curing process were numerically studied. The results show that different thermal environments have little effect on the peak temperature of the patch, which is within 0.8%; for the curing method of the heat-blanket, increasing the heating rate can shorten the curing time of the patch, but it will increase the residual stress, and the time required to complete the curing is shortened by 23% with the residual stress increased by 9%, when the heating rate increases from 2 K/min to 6 K/min. For the autoclave curing mode, the residual stress in the patch can be reduced and the curing time will not be prolonged while decreasing the convective heat transfer coefficient in the autoclave, and the residual stress is decreased by 12.3% when the convective heat transfer coefficient decreases from 63 W/(m²·K) to 23 W/(m²·K); and the residual stress corresponding to the autoclave curing method is 7% smaller than that corresponding to the heat-blanket curing method, while the curing time is close for two curing methods. However, the curing cost for the autoclave is much higher than that for heat-blanket, so the curing process of the heat-blanket can be continuously optimized to achieve the goal of improving the curing quality and reducing the curing cost.

Key words: finite element, heating rate, convective heat transfer coefficient, temperature field, residual stress, composites