Mechanical performances of composite orthogrid stiffened cylinder manufactured by an improved method

With high specific strength and stiffness, composite orthogrid stiffened cylinder (COSC) possesses excellent potential in the aerospace industry. However, the traditional silicone mold preparation methods have poor manufacturing accuracy and a low reuse rate of the mold. This work presents an improved COSC manufacturing method based on a combined metal mold and prepreg laying process. High-precision COSCs with intersection fillets were manufactured by the improved method. Axial compression was performed to reveal the strength and failure mode of the cylinder. Rib fracture and end delamination are the primary failure modes of the COSC under compression. Compared with relevant cylinders, the peak failure load, specific compression strength, and compression stiffness of the cylinder are significantly improved. Fillets wrapped around the intersection can effectively protect the fragile intersection roots. On this basis, an explicit dynamic simulation method simultaneously considering linear buckling mode and Hashin failure criterion is proposed to predict the peak failure load and fracture behavior of the cylinder.