DOES THE MULTIPLE CURING STAGE APPROACH REDUCE THE SPRING-IN ANGLE OF A CURVE-SHAPED COMPOSITE LAMINATE? A COMPREHENSIVE STUDY OF EXPERIMENTS AND MODELING

摘要

The occurrence of dimensional infidelity caused by the curing process can be detected as a curved composite is released from the mold after full consolidation. On the other hand, lengthy cure cycle, thermal spiking and non-uniform consolidation in thick composite manufacturing are often strong deterrents to widespread industrial implementation. The composite processing technique of multi-stage curing is useful for mitigating the effects of thermal spiking, non-uniform consolidation and fiber wrinkling on mechanical integrity for thick curved-composite structures. However, the prediction of spring-in behavior for a multi-stage curing process is still a relatively unexplored area in composites research. Therefore, the spring-in phenomenon of the multi-stage curing process is investigated in this research. A new compatibility model for predicting the spring-in of a multi-stage curing process, which combines the energy balance, thermal-elastic solution and curved beam theory, is presented in this paper. Several composite laminates are manufactured to validate the spring-in model for multi-stage curing process.