Steel sides of dump tractor trailers used in the transportation of bulk and semi-liquid agricultural goods are subject to active abrasive wear and corrosion. The article proposes replacing the existing design of the sides, instead of steel sheets to use multilayer composite plates, which will increase the reliability and service life of the machine as a whole. (Research purpose) The research purpose is developing a design and methodology for calculating the hinge fastening of a composite side to the agricultural vehicle. (Materials and methods) The article analyses the existing metalcomposite compounds. When using multilayer sandwich-structured composites, all layers do not adhere to the metal base. We have developed a design of a pivotally movable side support of the trailer, which provides a tight connection due to the introduction of a metal steel element into the prepreg, consisting of a plate with studs and an axle welded to it. Additional tightening of the support due to threaded connections made it possible to connect a multilayer composite with metal plates. (Results and discussion). The article presents the equation of node loading to determine the maximum force acting on the fastener. The calculation of the most loaded part, the fastener, was carried out according to the permissible stresses of the cut of its cylindrical part. (Conclusions) The expediency of using power structures of vehicles of the agro-industrial complex exposed to abrasive wear and corrosion made of polymer composite materials is confirmed. A new design of a detachable swivel joint of a multilayer composite side with a metal frame was created.