Development Technique of Large Composite Tank for Aerospace Vehicle

The development techniques of large composite overwrapped pressure vessel(COPV) with metal liner for aerospace vehicle are summarized based on present design and flight heritage, including technique development, material selection, structure design, reliability design, manufacturing process, qualification test and tank standard. The development technique characteristic analysis is finished. The material development trend and characteristic of both liner and carbon fiber reinforced plastic (CFRP) material are introduced. Three typical structure design methods are introduced, including conventional grid theory (CGT), optimized grid theory (OGT) and finite element analysis (FEA). The reliability design method are studied, which included stress rupture life analysis, low fatigue life analysis and reliability design calculation theory. The main trend of large COPV is summarized. This paper integrates material selection and characterization, design methods analyses of composite layers and structural design and fabrication of composite tanks. COPVs require the CFRP layers to carry most static internal pressure, dynamic loads and environmental loads. The paper presents results of work of (Lanzhou Institute of Physics)LIP to develop high performance COPV. Preliminary design analysis of COPV have been accomplished. For the safe of reliability of COPV, it is important to study the failure mode of CFRP stress rupture. This paper addresses a method for analyzing COPV using the CFRP grid theory and FEA software.