ANALYSIS OF SUPPORTING PLATE FASTENING CONSIDERING LOADING ECCENTRICITY

Abstract

To ensure manufacturability, cooperation, and an acceptable level of cost of aircraft manufacturing and operating, structural and technological sectioning is performed at different levels of a structure: parts, assemblies, units, bays etc. They are interrelated with each other and interact in a certain order using various forms of joints. Thus, it can be reasonably stated that perfection of aircraft in various appearances is largely determined by joints. On the other hand, at the stage of developing the main load-carrying scheme of a structure, simplified models are used, where the attachment zone or concentrated load is represented as a geometric locus of conditional points, where the reactions are summed up. Thus, the procedure for attachment designing, loads, etc. is completely independent, where the results of preliminary structure design in regular zones are used as initial data. It should be noted that the design of fastening units is carried out under more severe conditions than in regular structures: it is necessary to "fit" into the allowed space, fastening and supporting elements are selected according to standards for metal products, etc. A separate group of problems is created by the fact of using composites in load-carrying structures. These problems are associated with the distinctions of composites behavior in transition zones. On the other hand, the calculation and design of joints are limited by selected models.

Currently, fittings of support plate connection with main structure is least studied, especially under condition of loading with eccentricity. The solution of this problem is to ensure maximum universalization of joint model in order to expand the area of use, while maintaining accessibility for engineering calculations and design. The article presented to your attention is devoted to the development of joint model and parametric research of influence of additional parameters on conditions for including joint components in operation. This model allows to expand the list of design parameters for base plate attachment with conventional fasteners of various compositions (diameter, length of fastener body, material). In addition, the model allows to consider the value of the local thickness of composite package of joining parts and values of their local stiffness.