Li Weidong, Ma Zhengzheng, Shen Pengfei, Luo Chuyang, Zhong Xiangyu, Jiang Shicai, Bai Weihua, Xie Luping, Hu Xiaolan, Bao Jianwen
National Key Laboratory of Advanced Composites, AVIC Composite Technology Center, AVIC Composite Corporation Ltd., Beijing 101300, China.
Collaborative Innovation Center for Civil Aviation Composites, Donghua University, Shanghai 201620, China.
Materials (Basel). 2023 Jul 21;16(14):5156. doi: 10.3390/ma16145156.
In the face of the difficulty in achieving high-quality integrated molding of longitudinally and transversely stiffened panels for helicopters by resin-matrix composite materials, we combine the prepreg process and the resin transfer molding (RTM) process to propose a hybrid resin transfer molding (HRTM) for composite stiffened panel structures. The HRTM process uses a mixture of prepreg and dry fabric to lay up a hybrid fiber preform, and involves injecting liquid resin technology. Using this process, a longitudinally and transversely stiffened panel structure is prepared, and the failure modes under compressive load are explored. The results show that at the injection temperature of the RTM resin, the prepreg resin dissolves slightly and has little effect on the viscosity of the RTM resin. Both resins have good miscibility at the curing temperature, which allows for the overall curing of the resin. A removable box core mold for the HRTM molding is designed, which makes it convenient for the mold to be removed after molding and is suitable for the overall molding of the composite stiffened panel. Ultrasonic C-scan results show that the internal quality of the composite laminates prepared using the HRTM process is good. A compression test proves that the composite stiffened panel undergoes sequential buckling deformation in different areas under compressive load, followed by localized debonding and delamination of the skin, and finally failure due to the fracture of the longitudinal reinforcement ribs on both sides. The compressive performance of the test specimen is in good agreement with the finite element simulation results. The verification results show that the HRTM process can achieve high-quality integrated molding of the composite longitudinally and transversely stiffened panel structure.
针对直升机用树脂基复合材料难以实现纵向和横向加筋板高质量整体成型的问题，我们将预浸料工艺与树脂传递模塑（RTM）工艺相结合，提出了一种用于复合材料加筋板结构的混合树脂传递模塑（HRTM）工艺。HRTM工艺使用预浸料和干织物的混合物铺放混合纤维预制件，并涉及注入液态树脂技术。采用该工艺制备了纵向和横向加筋板结构，并探索了其在压缩载荷下的失效模式。结果表明，在RTM树脂的注射温度下，预浸料树脂略有溶解，对RTM树脂的粘度影响很小。两种树脂在固化温度下具有良好的混溶性，这使得树脂能够整体固化。设计了一种用于HRTM成型的可拆箱型芯模具，便于成型后脱模，适用于复合材料加筋板的整体成型。超声C扫描结果表明，采用HRTM工艺制备的复合材料层压板内部质量良好。压缩试验证明，复合材料加筋板在压缩载荷下不同区域依次发生屈曲变形，随后蒙皮出现局部脱粘和分层，最终由于两侧纵向加强肋断裂而失效。试验件的压缩性能与有限元模拟结果吻合良好。验证结果表明，HRTM工艺能够实现复合材料纵向和横向加筋板结构的高质量整体成型。
