Elastic/Plastic Behavior of Infinitely Long Cylinders Subject to Mechanical and Thermal Loads by Peter P. Poworoznek An Engineering Project Submitted to the Graduate Faculty of Rensselaer Polytechnic Institute in Partial Fulfillment of the Requirements for the degree of MASTER OF MECHANICAL ENGINEERING Approved: _________________________________________ Professor Ernesto Gutierrez-Miravete, Project Advisor Rensselaer Polytechnic Institute Hartford, CT December, 2008 PROPOSAL This project will examine the elastic-plastic behavior of both thin-walled and thickwalled infinitely long cylinders with plane-stress and plane-strain conditions at the ends subject to axisymmetric mechanical (pressure) and thermal loading. APPROACH/METHODOLOGY Initially, the elastic solution to an infinitely long cylinder subject to an internal pressure will be derived analytically using classical shell theory. Then the effects of adding a thermal load on top of an existing pressure will be examined. Next the pressure loads will be increased to induce plasticity in the cylinder for a strain-hardening material. Finally thermal effects will be added to complete the elastic-plastic analysis. Once the analytical solution is complete, the exact solutions will be used as baselines to validate the finite-element analyses. Using both shell and solid finite elements, solution convergence (vs. mesh size) and solution methods will be examined to determine the best approach. TOOLS For the theoretical part of the project, both Maple and MathCad will be used. For the finite-element portion, the ABAQUS non-linear finite-element code will be employed. REFERENCES [1] Young, W.C., 1989, Roark’s Formulas for Stress & Strain, McGraw-Hill, New York, NY. [2] Hill, R., 1950, The Mathematical Theory of Plasticity, Oxford University Press, London, UK. [3] Ugural, A.C, 1999, Stresses in Plates and Shells¸ McGraw-Hill, Boston, MA. [4] Batra, R.C., Iaccarino, G.L., 2008, “Exact solutions for radial deformation of a functionally graded isotropic and incompressible second-order elastic cylinder,” International Journal of Non-Linear Mechanics 43 383-398. [5] Bhattacharyya, A., Appiah, E.J., 2000, “On the exact solution of elastoplastic response of an infinitely long composite cylinder during cyclic radial loading,” Journal of the Mechanics and Physics of Solids 48 1065-1092. [6] Desikan, V., Sethuraman, R., 2000, “Analysis of material nonlinear problems using pseudo-elastic finite element method,” Journal of Pressure Vessel Technology 122 457461. [7] Gao, X.L., 2003, “Elasto-plastic analysis of an internally pressurized thick-walled cylinder using a strain gradient plasticity theory,” International Journal of Solids and Structures 40 6445-6455. [8] Jahanian, S., 1996, “Thermoelastoplastic stress analysis of a thick-walled tube of nonlinear strain hardening,” Transactions of the ASME 118 340-346. [9] Loghman, A., Wahab, M.A., “Loading and unloading of thick-walled cylindrical pressure vessels of strain-hardening material,” Journal of Pressure Vessel Technology 116 105-109. [10] Tarn, J.Q., 2001, “Exact solutions for functionally graded anisotropic cylinders subjected to thermal and mechanical loads,” International Journal of Solids and Structures 38 8189-8206. [11] Yi, W., Basavaraju, C., 1996, “Cylindrical shells under partially distributed radial loading,” Transactions of the ASME 118 104-108. [12] Zhao, W., Seshadri, R., Dubey, R.N., 2003, “On thick-walled cylinder under internal pressure,” Journal of Pressure Vessel Technology 125 267-273. SCHEDULE Proposal draft (Deliverable) – 9/23 Linear elastic stresses and strains (analytical) o Pressure loading, thin/thick-shells – 10/7 o Pressure loading with thermal effects, thin/thick shells– 10/14 First progress report (Deliverable) – 10/14 Elastic-plastic stresses and strains (analytical) o Pressure loading with thermal effects, thin/thick shells – 10/28 Linear elastic FEA analysis o Pressure loading with thermal effects, thin/thick-shells – 11/4 Second progress report (Deliverable) – 11/4 Elastic-plastic FEA analysis o Pressure loading with thermal effects, thin/thick-shells – 11/18 Final draft (Deliverable)– 11/25 Final report (Deliverable) – 12/9