温/热成形Steel/CFRP构件的宏微观缺陷及其成形机理

Macro and Micro Defects Formation Mechanism of Steel/CFRP Structures Fabricated by Using Warm/thermo Forming Process

对温热成形工艺制造的Steel/CFRP复合材料盒形件进行宏、微观缺陷观察,分析其缺陷形成机理。采用高压水射流切割技术在Steel/CFRP盒形件不同部位取样,以测量其壁厚分布,并进行微观界面观察。研究发现:Steel/CFRP盒形件典型的宏观缺陷主要包括:起皱、贫树脂区及富树脂区形成、厚度分布不均匀等。微观缺陷主要包括:孔隙、纤维束边界、裂缝、纤维断裂等。基于对上述缺陷形成机理的分析,提出可能采用的缺陷控制措施,如采用分段压边圈、单面预浸料、可提供侧压力的模具、适当的压延筋布置和铺层设计等,以改进Steel/CFRP构件成形质量,提高其服役安全性。

Steel/CFRP box-shape structures were fabricated by using the warm/thermo forming process to observe their macro-and micro-defects and analyze the formation mechanisms of these defects.In order to evaluate the wall thickness distribution of the formed Steel/CFRP box-shape structure and to examine its crosssection defects,the water jet cutting technique was applied to cut samples from the specified zones of Steel/CFRP structures.The research results indicate that the macro formation defects include wrinkling,resin poor and rich areas,the non-uniform thickness distribution,etc.While,the micro formation defects mainly consist of voids,boundaries of fiber bundles,cracking,carbon fiber yarns breakage, and so on.Based on the analysis of formation mechanisms for the defects mentioned above,some potential defect control measures are proposed to improve the quality and safety of Steel/CFRP structures,such as applying a segment blank holder,single side prepreg,mould with a lateral pressure,proper drawbead layout and stacking sequence,etc.