Abstract
In this study the author tried to establish a mathematical model based on Theory of Plates and Shell which includes parameters such as critical thrust force and material properties of composite tubes. Drilling is frequently applied in manufacturing laminate plates for joining parts together, which often causes delamination at the interface between drills and plates. The defect happens in drilling composite thin tubes too. Delamination is one of the major concerns in composite drilling, which will reduce the mechanical strength of composite material. For increasing usage of composite thin tubes in aerospace and automobile, delamination prediction is of serious safety interest.