Manoj Sahni

Thermal elastic-plastic transition of non-homogeneous thick-walled circular cylinder under external pressure

Stresses in the elastic-plastic state have been obtained under external pressure for a circular cylinder using transition theory. Graphs are drawn for stresses against radii ratio and the results are discussed numerically. From the numerical results, it is observed that without the introduction of temperature homogeneous cylinder is on the safer side of the design while with the introduction of temperature non-homogeneous cylinder is on the safer side of the design. Also highly compressible circular cylinder made of homogeneous/non-homogeneous material is on the safer side of the design as compared to less compressible circular cylinder.

Creep Deformation of a Thin Rotating Disk of Exponentially Varying Thickness with Inclusion

Creep stresses and strain rates have been obtained for a thin rotating disc of exponentially varying thickness with inclusion using transition theory. Results obtained have been discussed numerically and depicted graphically. It has been observed that circumferential stress is less for the disk whose thickness decreases exponentially along radius as compared to the flat disk. With the introduction of compressibility parameter, there is small decrease in circumferential stress as compared to the disk made of incompressible material. It is concluded that disk made of compressible material is on the safer side of the design as compared to the incompressible disk with exponentially variable thickness as well as to the flat disk.

Numerical solution for FGM disk with variable thickness in a quadratic and cubic form

In this study, mechanical analysis of a rotating disk made up of functionally graded material has been conducted. The disk has a thickness variation in a quadratic and cubic form, along the radius, and the results are compared with the disk with constant thickness. The expressions are derived for an annular rotating disk with free-free boundary condition and the behaviour of FGM disk under different grading index and thickness profile is investigated and compared with the already known solution. The results for constant thickness and constant volume density are same as those derived in literatureIn this study, mechanical analysis of a rotating disk made up of functionally graded material has been conducted. The disk has a thickness variation in a quadratic and cubic form, along the radius, and the results are compared with the disk with constant thickness. The expressions are derived for an annular rotating disk with free-free boundary condition and the behaviour of FGM disk under different grading index and thickness profile is investigated and compared with the already known solution. The results for constant thickness and constant volume density are same as those derived in literature

Creep deformation of a non-homogeneous thin rotating disk of exponentially varying thickness with internal pressure

In this paper, the creep stresses – radial and circumferential have been obtained for a thin disk rotating with a fixed angular speed. The thickness of the disk decreases radially from inner to outer where as the compressibility increases radially. The disk is axis-symmetric and is in a state of plane stress. It has been observed that variation in thickness and compressibility has significant effects on the stresses for an annular disk. It has been concluded from the discussion that circumferential creep stresses for highly non-homogeneous disk are at the lower side as compared to the circumferential creep stresses for homogeneous disk which leads to the result that highly non-homogeneous disk is better choice for the designing purpose as compared to homogeneous disk.

Finite deformations of functionally graded shell under outer pressure with steady state temperature

In this paper, finite elastic and plastic stresses have been determined for functionally graded shell using the concepts of transition theory and generalized measure of strain i.e. nonlinear terms in the displacements are also considered while in classical theory only infinitesimal strain theory concept has been applied. In this problem of spherical shell, temperature has been applied at the internal surface while pressure is considered to be applied at the external surface. From the detailed analysis, it has been noticed that temperature and pressure have significant effects on functionally graded shell. In this paper, it is found that external pressure required for the fully plastic state from initial yielding is on the higher side for the shell made up of highly functionally graded material as compared to the shell made up of less functionally graded material.In this paper, finite elastic and plastic stresses have been determined for functionally graded shell using the concepts of transition theory and generalized measure of strain i.e. nonlinear terms in the displacements are also considered while in classical theory only infinitesimal strain theory concept has been applied. In this problem of spherical shell, temperature has been applied at the internal surface while pressure is considered to be applied at the external surface. From the detailed analysis, it has been noticed that temperature and pressure have significant effects on functionally graded shell. In this paper, it is found that external pressure required for the fully plastic state from initial yielding is on the higher side for the shell made up of highly functionally graded material as compared to the shell made up of less functionally graded material.

Stress Analysis of a Pressurized Functionally Graded Rotating Discs with Variable Thickness and Poisson’s Ratio

This paper deals with the analytical study of stress analysis and effect of variable thickness with variation in Young’s modulus and constant Poisson ratio of Pressurized Functionally Graded Rotating Discs. In another case, the functionally graded material with constant thickness and variable Poisson ratio is studied, so that the effects of Poisson ration can be analyzed. Stress analysis has been done on the rotating discs of constant thickness as well as the varying thickness and it comes out that variable thickness discs perform better than constant thickness with varying Poisson’s ration as it shows a significant decrease in stresses.

Elastic-Plastic Analysis for a Functionally Graded Rotating Cylinder Under Variation in Young’s Modulus

In engineering applications, pure metals are rarely used because the application may require a material with different properties that is hard as well as ductile. The functionally graded materials are the materials obtained from the composition of two or more different materials, different in properties from the constituent material, to enhance the strength of the resultant material. The concept was introduced in Japan during a space plane project in 1984. Since then, a lot of research work has done in this area under various profiles and under various conditions.

Analysis of safety measure in creep transversely isotropic thick-walled rotating cylinder by finitesimal deformation under external pressure

Creep stresses have been obtained for a transversely isotropic thick-walled rotating circular cylinder under external pressure using Seths transition theory. From the numerical results obtained, it is seen that the stress due to rotation for cylinder made of transversely isotropic material with measure N = 1 is large as compared to cylinder made of isotropic material. It is concluded that cylinder made of isotropic material with measure N = 1 is on the safer side of the design as compared to cylinder made of transversely isotropic material with measures as N = 1, 3, 5.