Stress state of thin-walled composite sections under temperature and technological impacts.

Composite rod systems belong to the category of new structural systems, which allow (on condition of the rational designing) creating the effective engineering solutions for the load-bearing structures intended for various applications. These structures are adapted to the stress-strain behavior, possess improved bearing capacity, stiffness and at the same time provide reduced consumption of materials. However, for the designing of composite rod systems, it is necessary to generalize the traditional methods for thin-walled rods calculations, which allow taking into account anisotropic and layered structure of composites. Based on the analysis of the nature of the technological and temperature impacts on a composite rod with non-homogeneous cross-section, the method for determining the temperature stresses in the rod elements, leading to its complex flexural-torsional deformed state, has been developed. The method provides assessment of two-dimensional stress field in the section elements and local features of configuration of thin-walled rod. Using the example of angle section with the reinforcing plate, dependences of the internal stresses on the structural, technological and operational parameters are studied. Thickness and length of legs of the angle section were chosen as the geometric parameters; change in the temperature of the section during its manufacture served as the technological factor; angle of reinforcement of the regular part of the composite section was taken as the additional structural factor. It is concluded that in order to reduce stresses and, as a consequence, the subsequent buckling of the section, it is necessary to aim for using the lower curing temperature ranges and close values of angles of laying of the reinforcing plate and the basic section. Based on the parametric studies, practical recommendations have been developed for the designing and manufacture of thin-walled composite sections, and measures to reduce the magnitude of stresses and deformations arising at the stage of production of articles have been proposed. [ABSTRACT FROM AUTHOR]