Secondary Creep Analysis of FG Rotating Cylinder with Exponential, Linear and Quadratic Volume Reinforcement

Abstract

Creep is an irreversible time-dependent deformation in which a material under constant mechanical stress and elevated temperature for a considerably prolonged period of time, starts to undergo permanent deformation. Creep deformation occurs in three stages namely, primary, secondary and tertiary. Out of these three stages, secondary or steady state creep is particularly an area of engineering interest as it has almost a constant creep rate. Creep deformation plays a significant role in understanding effective service life of an engineering component working under high temperature conditions as such components such as super-heater and re-heater tubes and headers in a boiler, jet engines operating at temperature as high as 1200 ∘C, usually experience a failure or rupture due to creep phenomenon. Design engineers keep a close attention on working stress conditions and elevated temperature under which an engineering component is expected to work as these conditions determine the onset of creep behavior in an engineering component. By recognizing the parameters of material response to creep behavior, engineers can analyse the useful service life and hazardous working conditions for an engineering components. Recognizing the creep phenomenon as high temperature design limitation, ASME Boiler and Pressure Vessel Code have provided guidelines on maximum allowable stresses for materials to be used in creep range. One of the criteria for determination of allowable stresses is 1% creep deformation of material in 100,000 h of service. Thus, the study of creep behavior in engineering components pertaining to high stress and temperature working conditions is very important as it affects the reliability and performance of the engineering components. The aim of our study is to understand the behavior of secondary creep deformation so that an advanced reinforced functionally graded material with better creep resistance, can be designed. In this paper, a secondary creep analysis of functionally graded (FG) thick-walled rotating cylinder under internal and external pressure is conducted. The novelty of the model intends to specify secondary creep stresses and strains by employing exponential, linear and quadratic volume reinforcement for SiCp ceramic in Al metal matrix in radial direction. This will help us to understand the effect of volume reinforcement in FG cylinder under internal/external pressure and rotating centrifugal body force by obtaining secondary creep stresses and strains. The response of the FG cylinder with isotropic material is analyzed and the solution for stress–strain rates in radial and tangential directions are obtained in closed form. Comparison of steady state creep stresses and strains under exponential, linear and quadratic volume reinforcement profiles are discussed and presented graphically.

Numerical Simulation of Stresses in Functionally Graded HCS-MgO Cylinder Using Iterative Technique and Finite Element Method

“…Figure 2 presents the variation of Young's modulus in FGM and non-FGM cylinders. The Young's modulus for the FGM cylinder is continuously increasing under an exponential profile given by Equation (1).…”

“…There are several structural components with a cylindrical shape, which are commonly used in many engineering applications such as pressure vessels, submarine, boiler, gun pipe, drive shaft, CNG storage cylinder etc. Due to the sharp interface in the traditional composite material a serious drawback of delamination was observed by Japanese material scientists during the aerospace project in 1984 [1]. This material failure was one of the major causes that led to the development of functionally graded materials (FGMs).…”

“…The elastic properties at macroscopic variation, inherent to functionally graded materials (FGMs), were introduced at the element level by means of nodal based gradation, often via an auxiliary (non-physical) temperature-dependence and a Gauss integration point based gradation. Sahni et al [1] presented a secondary creep stress-strain analysis of a pressurized cylinder made up of FGM and demonstrated the effect of varying the volume reinforcement of ceramic in a metal matrix on creep stresses and strains in a functionally graded rotating cylinder. In this study, an axisymmetric thick hollow FGM cylinder is considered, which is made up of High Carbon Steel (HCS) as the inner, and magnesium oxide (MgO) as the outer, material.…”

Exploring the effective stress behavior of internally pressurized cylinders with varying density

“…Askari et al [11] introduce analytical closed-form solutions for predicting the transverse mechanical properties of matrix-filled carbon nanotubes, achieving remarkable agreement with finite element analysis results. Meanwhile, Sahni et al [12] embark on an exploration into creep analysis within a rotating cylinder, incorporating linear, quadratic volume reinforcement, and exponential factors. Their primary objective is to gain profound insights into the intricacies of secondary creep deformation, thereby enabling the development of an advanced, fortified functionally graded material with enhanced resistance against creep.…”

Creep Analysis of Rotating Thick Cylinders Subjected to External and Internal Pressure: Analytical and Numerical Approach

“…By understanding how the material behaves under sustained loads and elevated temperatures, engineers can estimate how long the cylinder can operate safely before reaching a critical level of deformation [9][10][11]. Creep analysis allows engineers to select material that can withstand operating condition and also permit engineer to schedule effective maintenance [12]. Most engineering applications involve thick cylinders subjected to severe loadings, including both mechanical and thermal, which may result in considerable creep and ultimately reduce its operational life.…”