On analysis of spatial elastoplastic composite bars

We studied spatial composite rods with lengthwise variable cross sections inclusive of open profile thin-walled branches with curved shapes or broken circuits. The branches are connected by multiple-panel structural relationships. We used the basic provisions of the general theory of elastic spatial working composite bars designed by A.R. Rzhanitsina. The torque is transmitted along the length of the rod panels through its own torsion rigidity and stiffness of structural connections. A replacement of the system of differential equations by the system of finite difference equations is conducted. The system contains parameters considering physical and geometric nonlinear features of the problem to be solved. We used an expression obtained by the author to determine the modulus of the strain-sensitive inelastic behaviour of the branches and connections between them. The expression was also used to determine compliance of the composite rod in torsion. The above mentioned solution allows spatial deformation calculation of an inelastic composite rod with specific boundary conditions.