Application of a Creep-Damage Constitutive Model for the Rotor of a 1000 MW Ultrasupercritical Steam Turbine

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Jishen Jiang ◽  
Weizhe Wang ◽  
Nailong Zhao ◽  
Peng Wang ◽  
Yingzheng Liu ◽  
...  
Keyword(s):  
Constitutive Model ◽  
Steam Turbine ◽  
Creep Damage ◽  
Turbine Rotor ◽  
Creep Analysis ◽  
Wide Range ◽  
Damage Constitutive Model ◽  
Creep Constitutive Model ◽  
Basic Features ◽  
Heat Resistant Steels

A damage-based creep constitutive model for a wide stress range is applied to the creep analysis of a 1000 MW ultrasupercritical steam turbine, the inlet steam of which reaches 600 °C and 35 MPa. In this model, the effect of complex multiaxial stress and the nonlinear evolution of damage are considered. To this end, the model was implemented into the commercial software abaqus using a user-defined material subroutine code. The temperature-dependent material constants were identified from the experimental data of advanced heat resistant steels using curve fitting approaches. A comparison of the simulated and the measured results showed that they reached an acceptable agreement. The results of the creep analysis illustrated that the proposed approach explains the basic features of stress redistribution and the damage evolution in the steam turbine rotor over a wide range of stresses and temperatures.

Application of a Creep Damage Constitutive Model for the Rotor of a 1000 MW Ultra-Supercritical Steam Turbine

2015 ◽  
Author(s):  
Jishen Jiang ◽  
Weizhe Wang ◽  
Nailong Zhao ◽  
Peng Wang ◽  
Yingzheng Liu ◽  
...  
Keyword(s):  
Constitutive Model ◽  
Steam Turbine ◽  
Axial Stress ◽  
Creep Damage ◽  
Turbine Rotor ◽  
Creep Analysis ◽  
Wide Range ◽  
Damage Constitutive Model ◽  
Creep Constitutive Model ◽  
Basic Features

A damage-based creep constitutive model for a wide stress range is applied to the creep analysis of a 1000 MW ultra-supercritical steam turbine, the inlet steam of which reaches 600°C and 35 MPa. In this model, the effect of complex multi-axial stress and the nonlinear evolution of damage are considered. To this end, the model was implemented into the commercial software ABAQUS using a user-defined material subroutine code. The temperature dependent material constants were identified from the experimental data of advanced heat resistant steels using curve fitting approaches. A comparison of the simulated and the measured results showed that they reached an acceptable agreement. The results of the creep analysis illustrated that the proposed approach explains the basic features of stress redistribution and the damage evolution in the steam turbine rotor over a wide range of stresses and temperatures.

On real-time creep damage prediction for steam turbine

2022 ◽  
pp. 014233122110689
Author(s):  
Yongjian Sun ◽  
Bo Xu
Keyword(s):  
Finite Element ◽  
Steam Turbine ◽  
Real Time ◽  
Creep Damage ◽  
Element Model ◽  
Turbine Rotor ◽  
Theoretical Research ◽  
Element Analysis ◽  
Damage Prediction ◽  
Time Calculation

In this paper, in order to solve the calculation problem of creep damage of steam turbine rotor, a real-time calculation method based on finite element model is proposed. The temperature field and stress field of the turbine rotor are calculated using finite element analysis software. The temperature data and stress data of the crucial positions are extracted. The data of temperature, pressure, rotational speed, and stress relating to creep damage calculation are normalized. A real-time creep stress calculation model is established by multiple regression method. After that, the relation between stress and damage function is analyzed and fitted, and creep damage is calculated in real-time. A creep damage real-time calculation system is constructed for practical turbine engineering. Finally, a numerical simulation experiment is designed and carried out to verify the effectiveness of this novel approach. Contributions of present work are that a practical solution for real-time creep damage prediction of steam turbine is supplied. It relates the real-time creep damage prediction to process parameters of steam turbine, and it bridges the gap between the theoretical research works and practical engineering.

scholarly journals On the Kachanov-Rabotnov continuum damage model

2020 ◽  
Vol 53 (2) ◽  
pp. 125-144
Author(s):  
Harm Askes ◽  
Juha Hartikainen ◽  
Kari Kolari ◽  
Reijo Kouhia ◽  
Timo Saksala ◽  
...  
Keyword(s):  
Free Energy ◽  
Constitutive Model ◽  
Tensile Test ◽  
Helmholtz Free Energy ◽  
Damage Model ◽  
Continuum Damage ◽  
Dissipation Potential ◽  
Continuum Damage Model ◽  
Damage Constitutive Model ◽  
Basic Features

In this paper two partially complementary formulations of the simple phenomenological Kachanov-Rabotnov continuum damage constitutive model are presented. The models are based on a consistent thermodynamic formulation using proper expressions for the Helmholtz free energy or its complementary form of the dissipation potential. Basic features of the models are discussed and the behaviour in tensile test and creep problems is demonstrated.

A Multistage Creep Damage Constitutive Model for Isotropic and Transversely-Isotropic Materials With Elastic Damage

2011 ◽  
Author(s):  
Calvin M. Stewart ◽  
Ali P. Gordon
Keyword(s):  
Constitutive Model ◽  
Creep Deformation ◽  
Constitutive Models ◽  
Creep Damage ◽  
Transversely Isotropic ◽  
Common Source ◽  
Isotropic Materials ◽  
Damage Constitutive Model ◽  
Transversely Isotropic Materials ◽  
Elastic Damage

In the pressure vessel and piping and power industries, creep deformation has continued to be an important design consideration. Directionally-solidified components have become commonplace. Creep deformation and damage is a common source of component failure. A considerable effort has gone into the study and development of constitutive models to account for such behavior. Creep deformation can be separated into three distinct regimes: primary, secondary, and tertiary. Most creep damage constitutive models are designed to model only one or two of these regimes. In this paper, a multistage creep damage constitutive model is developed and designed to model all three regimes of creep for isotropic materials. A rupture and critical damage prediction method follows. This constitutive model is then extended for transversely-isotropic materials. In all cases, the influence of creep damage on general elasticity (elastic damage) is included. Methods to determine material constants from experimental data are detailed. Finally, the isotropic material model is exercised on tough pitch copper tube and the anisotropic model on a Ni-base superalloy.

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