Structures in the form of ribbed panels with sheathings from sheet materials are used in construction of buildings and structures of various purposes: civil, industrial, agricultural, etc. Panels are universal enclosures and supporting structures, they can be used as coverings, floors, walls. Ribbed coating slabs simultaneously perform the functions of roof purline, floorboards, sheathing, provide heat and sound protection of the building. They are characterized by unification, high level of factory readiness; the ability to control the strength, sound and heat-insulating properties, and low density of materials used, which allows significantly reducing the cost of laying the foundation of the building. The paper presents the results of investigations of the influence of various parameters on the stress-strain state of panels (type of joints, coefficient of stiffness of the bonded joints, the magnitude of the span, the width of the panel, and the material of anisotropic sheathing).To solve this problem, the well-known solution of the plane stress problem is used (Faylon method), in which the constants of integration are determined as the Fourier series expansion coefficient of contour loads. As a result of numerical researches, reduction coefficients for bendable ribbed wood-composite panels with mechanical joints were obtained.