热塑性复合材料自动铺放过程中红外加热技术研究

为保证热塑性预浸料树脂基体在自动铺放(automated fiber placement, AFP)过程中充分熔融,实现热塑性复合材料(thermoplastic composites,TPC)逐层"原位固结"成型,自动铺放成型过程中需精确控制预浸料的加热温度。针对自动铺放过程中铺放速率会在较大范围内变动的特点,本工作提出一种高速率响应的红外线辐射加热技术。通过对红外热源与铺层间能量传输过程的分析,提出红外加热过程中动态恒温控制方程,建立热源辐射强度与铺放速率之间的匹配关系。基于热塑性复合材料自动铺放实验平台,构建红外加热恒温控制系统,该系统采用前馈控制方式,根据动态恒温控制方程,制定相应控制策略,实现对预浸料加热过程中温度的精确控制。实验结果表明自动铺放过程中使用红外加热恒温控制系统满足变速工况下恒温加热要求,且铺放成型实验件的压缩强度及层间剪切强度均接近模压成型实验件。

Infrared heating system based on automated fiber placement for thermoplastic composites

In order to ensure the full melting of the thermoplastic composites (TPC) prepreg in the process of automated fiber placement (AFP) and offer the potential to realize the in-situ consolidation for TPC,it is necessary to control the temperature of the prepreg in AFP.Aiming at the processing speed will be changed within the larger scope,an infrared heating technology with fast response rate and efficient was proposed.Based on the analysis of the heat transfer process between the infrared heat source and the layers,the control equation of dynamic temperature was put forward and the matching relationship between the radiation intensity and laying speed was established.Based on the AFP platform,the infrared heating system which adopts the feedforward control method was constructed and the corresponding control strategy was formulated according to the dynamic thermostatic control equation to realize the heating temperature of prepreg controlled accurately.The experiment results show that the infrared heating thermostatic control system can meet the requirement of dynamic thermostatic control in the condition of variable speed and the compressive strength and the interlaminar shear strength for AFP component are closed to the moulded component.