The stress state in two-layer hollow cylindrical bars

The stress state of two-layer hollow bars in whichthey are exposed to axial load is analyzed. The layers are madeof isotropic, homogeneous, linearly elastic material, and thelayers are as concentric cylinders.A mathematical model for two-layer tension- compressioncylindrical bar axial, radial and ring stress and to setthe limit values in the layers is presented. To asses the stresscondition in the layers the expression of reletive stresses in thecontact zone is obtained. It enables to determine how much forthe construction under discussion, the stress state is threedimensional,two-dimensional or axial. For the relative stressdetermination a limit curve and its equation are proposed.It has been determined that the relative stresses dependon the values of Poisson's ratio, modulus of elasticity, theradial dimensions and cross-sectional layer areas ratios, also thelayout and construction materials. The analysis of the derivedequations demonstrated that in certain cases, radial and circularstresses may form a significant part of axial stress value. Themaximum relative stress-establish the proposed limit curvesequation.