ABSTRACT

One of the most promising fields of using load-bearing composite structures is manufacturing of thin-walled beams by winding or laying up of unidirectional rovings or fabric tapes at different angles to the longitudinal beam axis. Such beams are used as members of truss structures, aircraft propellers, helicopter rotor blades, and drive shafts. The beam as a structural element works in tension, compression, torsion, and flexure. The existence of the shear center allows independent consideration of beam bending and torsion. The maximum shear stress resultant is larger by 35% than nzso corresponding to free beam torsion. In the torsion problem, allowance for restrained warping of the cross section provides the observance of the normal stress resultant that is absent for free torsion. Composite materials are promising materials for manufacturing thin-walled beams with open cross-section contours. Such beams are usually manufactured by pultrusion, molding, lay-up, or winding.