Stress Distribution Of Cylinder Research Articles

Estimation of Creep Damage for the Components of Mod. 9Cr-1Mo Steel. 4th Report. Creep Damage Assessment for Circular Seam Welded Joint in Internally Pressurized Pipe.

In order to establish the assessment method of creep damage for high temperature piping components made of mod. 9Cr-1Mo steel with circular seam welded joint, the internal pressure creep tests and FEM stress analysis were done. Internal pressure creep tests showed the creep rupture occurred in the coarse grained heat affected zone (C. G. HAZ), caused by cracking originated from the formation of voids on grain boundaries. The void parameters such as void area fraction, density of void population and A parameter correlated well with time fraction in internal pressure creep tests. Vickers hardness decreased with creep times and correlated well also with time fraction of internal pressure creep tests. Stress distribution of cylinder with circular seam welded joint under internal pressure creep showed the maximum circumferential stress in C. G. HAZ where creep rupture occurred. The distribution of circumferential stress and creep damage calculated by using circumferential stress along specimen thickness were quite similar to that of void area fraction. The creep damage of circular seam welded joint under internal pressure creep could be estimated by the observation of void and the FEM stress analysis.

A General Formulation of Stress Distribution in Cylinders Subjected to Non-Uniform External Pressure

This work presents a two-dimensional stress analysis for elastic solid cylinders subjected to combined loading. The loading is generally formed with a number of concentrated and partially distributed forces all applied radially on the outer surface. The distributed forces cause pressures with non-uniform intensity along the circumferential direction. The cylinder is assumed to be long so that a state of plane-strain is valid. To obtain the stress distribution for the problem of partially distributed forces a new approach is followed first introduced in this paper. It is based on the expressions formed after using the theory of simple radial stress distribution when point-forces are applied on the cylinder and leads to the solution after direct integration. The total stresses due to both concentrated and distributed forces are obtained using the method of superposition. Apart from its simplified formulation, this general solution is always preferable since it proved to have a great advantage. As a result of not containing Fourier series, it eliminates some problems of convergence of the series at the boundaries that appear due to the Gibbs phenomena when the boundary conditions are a discontinuous function. Numerical results are presented for some interesting cases of loading conditions.

Investigation of the asymmetric stressed-strained state of transversely isotropic cylinders under different boundary conditions at the ends

Since solving problems of the stressed-strained state of elastic bodies in an exact three-dimensional poses considerable mathematical and computational difficulties, only for a small number of problems have the results of the solution been put in numerical form [8, 10, 15, 16, 18]. The stressed-strained state of three-dimensional bodies must be known in order to evaluate the strength capabilities of structural elements, both as a reference for models of applied theories of shells and as solutions obtained by approximate methods. In this article we consider the class of problems of the stressed-strained state of transversely isotropic hollow cylinders of finite length under asymmetric loads applied to the lateral surfaces and with different boundary conditions at the ends. The solution of that class of problems is constructed on the basis of separation of variables in the circumferential coordinate and solution of the two-dimensional boundary-value problem by the spline-collocation and discrete orthogonalization methods [4, 5, 6, 12, 13]. This approach was used earlier [1, 2, 7, 11] to solve two-dimensional problems of the theory of shells in different formulations. The influence of boundary conditions on the displacement and stress distribution in cylinders is analyzed on the basis of the results obtained. We consider transversely isotropic hollow cylinders in which the plane of isotropy coincides with the tangent to the cylindrical surface and the mechanical characteristics vary only along the normal to it. Asymmetrically distributed loads are applied to the lateral surfaces of the cylinder and boundary conditions are given at the ends. The problem is described on the basis of the three-dimensional theory of elasticity in a cylindrical coordinate system