Model of quality management of technical preparation for the metal+composite joints production

Modern aerospace structures widely use parts, panels and assemblies made of composites. Connecting them to metal tips is quite complicated problem. Known conventional methods of joints using bolts, rivets and adhesive ones do not meet the requirements for a number of reasons related to restrictions on weight, dimensions of joints, their reliability and manufacturability. In the world practice of such joints, many design and technological solutions for "metal+composite" joints are known. Among them, metal-composite heterogeneous connections with transversal fastening joints most fully meet the technical requirements. To connect composite tips of different structures with different shapes and grades of alloys of metal fittings, monolithic (with metal tips) fastening elements, pins (cylindrical, conical, pyramidal, etc.) and sheet microelements are used. The latter are attached to the metal tips in different ways. The microelements themselves can have different shapes from the top view and in longitudinal section. Depending on the direction and type of transmitted loads, the structure of the arrangement of elements on the surface of the metal tip can be different. In such multifactorial conditions, technical preparation of production, including design and technological preparation, is a complex task. It is necessary to consider that the goals of the production of such equipment may differ significantly – prototype (single piece) or mass production with different requirements for them. It is quite difficult to organize such production with technical preparation of high-quality production without a quality management model for the preparation process. The work proposes a comprehensive mathematical model for managing the quality of technical preparation for the production of joints based on a quantitative assessment of the properties of the main manufacturing processes. The controlled parameter in it is a complex quality index, and the controlling parameter is the weight factor of group or individual properties of the component processes. Setting the values of the weight coefficient of a particular property is carried out using an expert or analytical method in the range of values 0…1.0. In this case, the controlled parameter varies within 0.5…3.5. The indicated values are verified by calculation for different joint materials and processes of forming fastening microelements. Conclusions are drawn about the sufficient effectiveness of quality management of technical preparation for the production of metal+composite joints.