Elastoplastic Analysis of Ultimate Bearing Capacity for Multilayered Thick-Walled Cylinders Under Internal Pressure

The elastoplastic analysis based on the unified strength theory was performed to evaluate the ultimate bearing capacity of double- and multilayered thick-walled cylinders. The theory provides a new concept and method for the analysis of thick-walled cylinders. The solutions derived herein are widely applicable and can quantitatively account for different tension-compression strength values and mean principal stress. The fundamental solutions for single radii, assemblage pressure, and shrink range are derived with the yield condition of the theory. The traditional existing elastoplastic results by the Tresca or von Mises yield criteria can be seen as a particular case of the new solutions that can overcome shortcomings. The strength parameter, tension-compression strength ratio, radii ratio, and combined cylinder layers were taken as major theory variables for the unified solutions. The new solutions are versatile and can be adapted to the existing formulas, to more accurately calculate the structural stress conditions. The strength theory effect due to adopting different yield criteria is quite significant, which cannot be underestimated.