Stress state calculation of a repair of a uni- or biaxially loaded laminate structure

The growing use of fibre-reinforced plastics requires adequate maintenance and repair behavior of these materials compared with the traditional metallic alloys. Due to the low tensile strength of fibre-reinforced materials perpendicular to the fibre direction, a bonded repair is the most suitable one and it will be considered in this paper. Based on the classical lamination theory, a model for the calculation of the shear stresses in a bonded repair under biaxial loading is developed. In addition to a simple model neglecting the stresses perpendicular to the laminate-plane, which is applied for a uni- and biaxial load case, a more complex model taking these stresses into account is developed. These models allow an estimation of whether a damaged shell can be repaired or must be replaced.Presented at the Ninth International Conference on the Mechanics of Composite Materials (Riga, October, 1995).Published in Mekhanika Kompozitnykh Materialov, Vol. 31, No. 3, pp. 351–362, May–June, 1995.