The wing structure of an aircraft also served as a fuel tank containing fluid. The fuel tank and joint structure are made up of composite structures. Hydrodynamic ram (HRAM) effect occurs when the explosion or high speed object passes through the aircraft wing and high pressure is generated in the fuel tank. High pressure can cause failure in the fuel tank and on joint structure as well as other aircraft wing structures. To ensure the aircraft survivability design, we shall examine the behavior of the joint structures in HRAM effect. In this study, static tensile tests were conducted on four kinds of composite T-joints. The failure behavior of the composite T-joints was examined using strain gauges and high speed camera. The failure stresses and failure pressure of the composite T-joints were calculated by FEA. We also examined the validity of the Finite element modeling by comparing the results of FEA and static tensile tests.