One of the most important stages of creation of the diagnostical system «Signal – damage – remaining strength» is a multilevel strength analysis. Present work is dedicated to the first level of stress analysis. The essence of it for concrete joint is to determine the shear forces on a surface of contact of stringer and skin, which occur because of an iternal surplus pressure on a fuselage. With the help of parametrical modelling several models of a joint with the different relations between its independent variable parameters were created. The problem were solved by a finite element method.Graphical dependencies of distribution of shear forces along a surface of contact of stringer and skin, and also ones of the maximal values of shear forces on the independent variable parameters of a model when their different combinations were obtained as result.