Time-dependent creep analysis of rotating ferritic steel disk using Taylor series and Prandtl–Reuss relation

2013 ◽  
Vol 77 ◽  
pp. 40-46 ◽  
Author(s):  
Vahid Daghigh ◽  
Hamid Daghigh ◽  
Abbas Loghman ◽  
Andy Simoneau
Keyword(s):  
Taylor Series ◽  
Ferritic Steel ◽  
Time Dependent ◽  
Steel Disk ◽  
Creep Analysis

Analytical Solution for the Creep Problem of a Rotating Functionally Graded Magneto–Electro–Elastic Hollow Cylinder in Thermal Environment

2019 ◽  
Vol 11 (06) ◽  
pp. 1950053 ◽  
Author(s):  
M. Saadatfar
Keyword(s):  
Differential Equation ◽  
Hollow Cylinder ◽  
Thermal Loading ◽  
Thermal Environment ◽  
Functionally Graded ◽  
Time Dependent ◽  
Creep Stress ◽  
Creep Analysis ◽  
Magnetic Potentials ◽  
Creep Strains

In this paper, an analytical method is presented for the problem of the time-dependent response of a functionally graded magneto–electro–elastic (FGMEE) rotating hollow cylinder in thermal environment. The material properties of FGMEE are supposed to be power-law functions of radius. Applying the equations of equilibrium and electrostatic and magnetostatic equations, a differential equation which includes creep strains is achieved. At first, an exact solution for the primitive stresses, electric and magnetic potentials are achieved by eliminating creep strains in the mentioned differential equation. Then, Prandtl–Reuss equations, as well as Norton’s law, are employed for the FGMEE. Now, creep stress rates can be achieved by considering only creep strains in the mentioned differential equation. As a final step, time-dependent creep stress, electric potential and magnetic potential redistributions at any time can be achieved using an iterative method. Numerical examples are presented to disclose the influence of creep evolution, thermal loading, angular velocity and grading index on the primitive and creep response of the FGMEE hollow cylinder. Results show that the enhancement in tensile hoop stress during the creep evolution must be considered in designing. So, the creep analysis is vital to have more reliable and accurate aerospace smart structures.

MULTI-SCALE CREEP ANALYSIS OF PLAIN-WOVEN LAMINATES USING TIME-DEPENDENT HOMOGENIZATION THEORY: EFFECTS OF LAMINATE CONFIGURATION

2008 ◽  
Vol 22 (31n32) ◽  
pp. 6173-6178 ◽  
Author(s):  
K. NAKATA ◽  
T. MATSUDA ◽  
M. KAWAI
Keyword(s):  
Boundary Condition ◽  
Glass Fiber ◽  
Creep Behavior ◽  
Present Method ◽  
Time Dependent ◽  
Homogenization Theory ◽  
Multi Scale ◽  
Creep Analysis ◽  
Internal Structures ◽  
Woven Glass Fiber

In this study, multi-scale creep analysis of plain-woven GFRP laminates is performed using the time-dependent homogenization theory developed by the present authors. First, point-symmetry of internal structures of plain-woven laminates is utilized for a boundary condition of unit cell problems, reducing the domain of analysis to 1/4 and 1/8 for in-phase and out-of-phase laminate configurations, respectively. The time-dependent homogenization theory is then reconstructed for these domains of analysis. Using the present method, in-plane creep behavior of plain-woven glass fiber/epoxy laminates subjected to a constant stress is analyzed. The results are summarized as follows: (1) The in-plane creep behavior of the plain-woven GFRP laminates exhibits marked anisotropy. (2) The laminate configurations considerably affect the creep behavior of the laminates.

Comparison of the Isochronous Method and a Time-Explicit Model for Creep Analysis

2008 ◽  
Author(s):  
William Koves ◽  
Mingxin Zhao
Keyword(s):  
Elevated Temperature ◽  
Large Scale ◽  
Time Dependent ◽  
Creep Model ◽  
Full Time ◽  
Pure Bending ◽  
Stress Strain ◽  
Creep Analysis ◽  
Generalized Time ◽  
Strain Method

The design of components or structures at elevated temperature is complex. The use of rigorous time dependent material models may not be practical for many large scale industrial problems. The use of simplified methods permits the creep analysis of components that would be impractical by rigorous time dependent models. The Isochronous Stress-Strain method is an approach that has been used extensively for the creep evaluation of elevated temperature components. The method has been used for the analysis of problems containing both primary and secondary stresses. The method has also been used to evaluate creep buckling problems. Although the method has been accepted as an alternative to a full time dependent creep analysis, the limitations and accuracy of the method have not been investigated systematically and are not fully understood. This study compares the isochronous stress-strain method with a generalized time-explicit creep model for materials in high temperature applications. Analytical solutions are developed for three basic loading configurations, including uniaxial tension, pure bending, and torsion in either load or displacement controlled conditions. Deformations, stresses, and creep strains are compared between the two different methods.

Simplified, Detailed, and Isochronous Analysis and Test Results for the In-Plane Elastic-Plastic and Creep Behavior of an Elbow

1986 ◽  
Vol 108 (3) ◽  
pp. 297-304 ◽  
Author(s):  
L. H. Sobel ◽  
S. Z. Newman
Keyword(s):  
Creep Behavior ◽  
Bending Moment ◽  
Time Dependent ◽  
304 Stainless Steel ◽  
Plastic Behavior ◽  
Test Results ◽  
Creep Properties ◽  
Elastic Plastic ◽  
Creep Analysis ◽  
Simplified Analysis

Predictions obtained from simplified and detailed MARC analyses are compared with experimental results for the elastic-plastic and creep behavior of a 16-in-dia 304 stainless steel piping structure subjected to an in-plane closing bending moment. The piping structure is composed of a 90-deg elbow and two straight tangent pipes. The simplified analysis is found to considerably overestimate the measured results, especially for the case of creep behavior. The correlation of detailed analysis predictions with measured results is satisfactory for the elastic-plastic behavior of the structure, and inconclusive for the creep behavior, since the creep predictions are based on a commonly used creep law rather than on the actual (but unmeasured) creep properties. The paper also shows that predictions of creep deformation obtained from the relatively inexpensive time-independent isochronous method of analysis agree well with results given by a “complete” and more costly time-dependent creep analysis.

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