Investigation of stress distribution and damage behavior caused by forced installation of a composite bolted joint with a hole-location error

In this paper, the influence of forced installation caused by a hole-location error on the 3D stress distribution and damage of a composite bolted joint is investigated. An analytical model of stress distributed on composite holes is promoted, in view of non-uniform extrusion caused by forced installation. At first, non-uniform extrusion of the hole edge caused by forced installation is analyzed. According to the contact state, expression of hole deformation is given. Then, based on Hertz theory, the maximum extrusion load is obtained with help of deformation expression. By constructing an elastic foundation beam model, 3D stress distributed on a hole could be analyzed according to the extrusion load. Then, stress distribution predicted by the above analytical method is compared with that provided by FE considering composite damage. Finally, a forced installation experiment is carried out to analyze the damage distribution of the joint. Results show that a central-symmetrically distributed stress is introduced by the hole-location error. With an increment of the error, strength of composite decreases due to extrusion damage. Therefore, stress presents a concave distribution on the hole. As the hole-location error exceeding 3%, stress decreases gradually due to failure of composite. Damage of holes does not exhibit a centrosymmetric distribution. Serious damage is mainly distributed on the entrance of the hole at the lower sheet.