A Continuum Damage Mechanics Model on Creep Rupture Life Assessment of a Steam Turbine Rotor

2005 ◽  
Vol 128 (1) ◽  
pp. 173-177 ◽  
Author(s):  
Jing JianPing ◽  
Meng Guang ◽  
Sun Yi ◽  
Xia SongBo
Keyword(s):  
Steam Turbine ◽  
Damage Mechanics ◽  
Continuum Damage Mechanics ◽  
Turbine Rotor ◽  
Life Assessment ◽  
Continuum Damage ◽  
Creep Life ◽  
Steam Turbine Rotor ◽  
Mechanics Model ◽  
Nonlinear Continuum

A nonlinear continuum damage mechanics model is proposed to assess the high temperature creep life of a steam turbine rotor, in which the effect of mean stress is taken into account and the damage is accumulated nonlinearly. The model is applied to a 300 MW steam turbine under hot start operation. The results are compared with those from the linear accumulation theory that is dominant in the creep life assessment of steam turbine rotors at present. The comparison results show that the nonlinear continuum damage mechanics model describes the accumulation and development of damage better than the linear accumulation theory.

Continuum Damage Mechanics and Creep Life Analysis

1999 ◽  
Vol 67 (1) ◽  
pp. 193-196 ◽  
Author(s):  
G. J. Rodin
Keyword(s):  
Damage Mechanics ◽  
Continuum Damage Mechanics ◽  
Continuum Damage ◽  
Creep Life ◽  
Mechanics Model ◽  
Brittle Solids ◽  
Life Analysis

It is shown that the original continuum damage mechanics model of Kachanov is better suited for creep life analysis of creep-brittle solids and structures than continuum damage mechanics models that take into account damage-induced softening. [S0021-8936(00)03001-4]

Multiaxial Creep-Fatigue Life Prediction on the Rotor of a 1000MW Supercritical Steam Turbine

2012 ◽  
Author(s):  
Jianfeng Mao ◽  
Weizhe Wang ◽  
Yingzheng Liu ◽  
Junhui Zhang
Keyword(s):  
High Temperature ◽  
Steam Turbine ◽  
Damage Mechanics ◽  
Continuum Damage Mechanics ◽  
Continuum Damage ◽  
Mechanics Model ◽  
Creep Fatigue ◽  
Damage Accumulation Model ◽  
Multiaxial Creep ◽  
Comparison Of The Results

Damage of a high temperature rotor subjected to the creep-fatigue interaction was numerically investigated. Toward that end, a high temperature rotor of a 1000MW supercritical steam turbine was chosen for the study. A continuum damage mechanics model (CDM), which depicts the fatigue-creep interaction, was developed in the present paper. During the practical startup and shutdown processes, the influence of the multiaxial creep-fatigue interaction on strength of the rotor was analyzed in terms of stress, strain and damage. Comparison of the results from linear damage accumulation model (LDA) and CDM demonstrated that CDM was more reasonable to predict the lifetime of the rotor due to the multiaxial creep-fatigue interaction.

Assessment of Low Cycle Fatigue Life of Steam Turbine Rotor Based on a Thermodynamic Approach

2012 ◽  
Vol 134 (6) ◽  
Author(s):  
Yong-Jian Sun ◽  
Li-Sheng Hu
Keyword(s):  
Fatigue Life ◽  
Steam Turbine ◽  
Nonlinear Model ◽  
Damage Mechanics ◽  
Low Cycle Fatigue ◽  
Continuum Damage Mechanics ◽  
Turbine Rotor ◽  
Cyclic Stress ◽  
Cycle Fatigue ◽  
Steam Turbine Rotor

A new nonlinear model is proposed to assess the low cycle fatigue life of a 300 MW steam turbine rotor. Manson-Coffin equation and cyclic stress-strain relationship are employed to eliminate the unmeasured parameters, so all the parameters in model are measurable. Through comparison with that from the linear accumulation theory and continuum damage mechanics theory the results show this new nonlinear model describes the damage accumulation well and precisely in accordance with the practical test data. This approach supplies a new way to assess the damage of steam turbine rotor with satisfactory precision in engineering.

Creep Life Assessment of High Temperature Advanced Ultrasupercritical (AUSC) Conceptual Boiler Thick-Walled Pressure Components Using Continuum Damage Mechanics Approach

2016 ◽  
Author(s):  
B. Reddy Ganta ◽  
Monica Soare ◽  
Chen Shen
Keyword(s):  
High Temperature ◽  
Damage Mechanics ◽  
Base Material ◽  
Continuum Damage Mechanics ◽  
Life Assessment ◽  
Continuum Damage ◽  
Creep Life ◽  
Creep Properties ◽  
Design Life ◽  
Creep Life Assessment

Several nickel-based superalloys have been tested for high temperature applications for use in advanced ultra-supercritical (AUSC) fossil-fired power plants through laboratory and steam loops during the last several years. These materials include Inconel 740H and Haynes 282 which are found to have superior creep strength properties and be appropriate for use in the critical high pressure and high temperature (1400°F) AUSC boiler pressure parts such as superheater outlet header. While these materials have been extensively tested for their creep properties in laboratory test specimens, a real life design application with creep constitutive models is very limited. In this paper, development of a microstructure sensitive continuum damage mechanics (CDM) creep model for Haynes 282 base material that covers a wide range of stress levels and temperatures suitable for AUSC boiler design applications is described. Various creep mechanisms including diffusion and dislocation phenomena are included. This base material CDM model is then applied for a typical thick-walled high temperature header component and creep life assessment for the design life of the component is estimated. This analysis along with weldments and their creep properties still under development are considered crucial for identification of high creep damage regions in the component as well as proper design life assessment of the pressure parts.

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