摘要
目的研究不同放电能量对CFRP/Al夹层板电磁冲孔分层缺陷的影响。方法对2.4 mm厚的CFRP/Al夹层板进行电磁冲孔试验,通过超声C扫描无损检测技术、扫描电子显微镜及有限元数值模拟等手段分别对板料分层损伤、横截断面微观形貌及层间分层损伤进行评估,揭示不同放电能量对CFRP/Al夹层板电磁冲孔分层缺陷的影响。结果放电能量对电磁冲孔分层缺陷有显著影响。在4~6 kJ能量范围内,板料的最大分层因子(F_(d))和等效分层因子(F_(ed))均随放电能量的增加而减小。当放电能量为7 kJ时,等效分层因子F_(ed)仍然减小,但由于高速载荷作用下局部损伤的存在,使板料的最大分层因子Fd骤然上升,并超过了放电能量为4 kJ时的最大分层因子。结论在合理的能量范围内(4~6 kJ),随着放电能量的增加,能够明显提升CFRP/Al夹层板电磁冲孔的质量,但当放电能量过高(≥7 kJ)时,会产生额外的分层缺陷,影响冲孔质量。
The aim of this paper is to investigate the effect of different discharge energy on the delamination defect of holes produced by electromagnetic punching for hybrid CFRP/Al stacks.For this purpose,the electromagnetic punching experiments were carried out on hybrid CFRP/Al stacks with a thick of 2.4 mm.By means of ultrasonic C-scan technology,scanning electron microscope and numerical simulation,the delamination damage of CFRP/Al stacks,microstructure of cross section and inter-laminar delamination damage were evaluated,revealing the influence of discharge energy on the delamination defect of CFRP/Al stacks.The results showed that the discharge energy had significant effects on the delamination defect of the punched holes.In the range of 4 kJ to 6 kJ,the delamination factors(F_(d) and F_(ed))decreased with the increase of discharge energy.When the discharge energy is 7 kJ,the equivalent delamination factor Fed of CFRP/Al stacks still decreased,while the maximum de-lamination factor Fd rose abruptly and exceeded the maximum delamination factor when the discharge energy was 4 kJ.This was due to the presence of local damage under the action of high speed loading.Therefore,it could be concluded that,within a reasonable energy range(4~6 kJ),the electromagnetic punching quality of CFRP/Al stacks was significantly improved with the increase of discharge energy.However,when the discharge energy was too high(≥7 kJ),additional delamination defects would occur,affecting the punching quality.
作者
段丽明
洪志波
廖辉
崔俊佳
李光耀
蒋浩
DUAN Li-ming;HONG Zhi-bo;LIAO Hui;CUI Jun-jia;LI Guang-yao;JIANG Hao(State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body,Hunan University,Changsha 410082,China)
出处
《精密成形工程》
北大核心
2021年第4期67-75,共9页
Journal of Netshape Forming Engineering
基金
国家自然科学基金(52005173)
博士后创新人才支持计划(BX20200123)
长沙市自然科学基金(kq2014047)。
