Lialiukhina I. Design of composite beams and spars for aircraft load-carrying schemes.

Composite spars and beams of aircraft components are objects of studying; the objective of studying is to reduce the weight of the wing and control surfaces design of the aircraft through the rational design of spars and beam elements for strength, rigidity and stability on the basis of structural-manufacturing constraints and boundary effects. To determine the stress-strain state of wing spar elements are used the methods of beam theory, the theory of thin-walled rod and classical mechanics of laminated composite. In problems of stability the orthotropic plate design model is applied. Design parameters of composite spar is using the apparatus of differential and variation calculus. Theoretical and practical results are: the technique of design stress selection to operate with load of a single load case to ensure the strength of all modes of operation; a new algorithm for determination rational distribution of spar parameters is proposed to provide regulated deflection and bearing capacity by spar length; analysis schemes for determination additional Poisson's ratio and thermal stresses in the shoulders and caps are synthesized. Scientific novelty of the results is in primary formulation and solution of the problem of optimization the design parameters of spars and beams along the length and cross-section parameters on the condition of strength, all modes of stability, and regulated deflection in any arbitrary section in terms of structural and technological constraints and the specific characteristics of laminated composites . The results of the thesis are introduced in the educational process of the National Aerospace University "Kharkiv Aviation Institute" by specialty "Design and manufacturing of composite structures" in "Antonov" SR company and JSC "ONPP" Technology "(Obninsk, Russia). Area of application - aviation and rocket building.