scholarly journals Investigation on the validity of creep damage mechanics for the life time prediction of T92 welded joint

2019 ◽  
Vol 29 (3) ◽  
pp. 467-481 ◽  
Author(s):  
Xiao Wang ◽  
Xue Wang ◽  
Qiang Xu ◽  
Chuang Wang ◽  
Ya-lin Zhang ◽  
...  
Keyword(s):  
Damage Mechanics ◽  
Welded Joint ◽  
Rupture Life ◽  
Continuum Damage Mechanics ◽  
Creep Process ◽  
Continuum Damage ◽  
Creep Life ◽  
Fine Grained ◽  
Creep Time ◽  
The Continuum

This paper reports the damage evolution in ASME T92 welded joints during creep process. The creep test was conducted at 650℃ with applied stress of 90 MPa. The creep specimen was ultimately fractured at the fine-grained heat affected zones after creep for 1560 h. The metallographic results show that the cavity number and size in fine-grained heat affected zones increase with the creep time. The coalescence of creep cavities happened at the late stage of the creep life, which depending on the adjacent voids grows and propagates into the micro-crack. Besides, the deterioration in fine-grained heat affected zones of T92 steel welded joint with various creep time can be simulated based on the continuum damage mechanics with modified Kachanov-Rabotnov constitutive equation. The result of simulated creep rupture life is in good agreement with the experimental value, which indicates that the continuum damage mechanics can be used to predict creep life and evaluate creep deterioration in a T92 steel welded joint.

Creep Life Prediction of Aircraft Turbine Disc Alloy Using Continuum Damage Mechanics

2017 ◽  
Vol 38 (1) ◽  
pp. 25-30
Author(s):  
Yan-Feng Li ◽  
Zhisheng Zhang ◽  
Chenglin Zhang ◽  
Jie Zhou ◽  
Hong-Zhong Huang
Keyword(s):  
Numerical Analysis ◽  
Test Data ◽  
Life Prediction ◽  
Damage Mechanics ◽  
Continuum Damage Mechanics ◽  
Creep Model ◽  
Continuum Damage ◽  
Creep Life ◽  
Creep Life Prediction ◽  
Turbine Disc

Abstract This paper deals with the creep characteristics of the aircraft turbine disc material of nickel-base superalloy GH4169 under high temperature. From the perspective of continuum damage mechanics, a new creep life prediction model is proposed to predict the creep life of metallic materials under both uniaxial and multiaxial stress states. The creep test data of GH4169 under different loading conditions are used to demonstrate the proposed model. Moreover, from the perspective of numerical simulation, the test data with analysis results obtained by using the finite element analysis based on Graham creep model is carried out for comparison. The results show that numerical analysis results are in good agreement with experimental data. By incorporating the numerical analysis and continuum damage mechanics, it provides an effective way to accurately describe the creep damage process of GH4169.

Predicting the wear coefficient and friction coefficient in dry point contact using continuum damage mechanics

2018 ◽  
Vol 233 (3) ◽  
pp. 447-455 ◽  
Author(s):  
Sahar Ghatrehsamani ◽  
Saleh Akbarzadeh
Keyword(s):  
Friction Coefficient ◽  
Damage Mechanics ◽  
Point Contact ◽  
Continuum Damage Mechanics ◽  
Continuum Damage ◽  
Wear Coefficient ◽  
Mechanics Model ◽  
Pin On Disk ◽  
Disk Test ◽  
The Continuum

Wear coefficient and friction coefficient are two of the key parameters in the performance of any tribo-system. The main purpose of the present research is to use continuum damage mechanics to predict wear coefficient. Thus, a contact model is utilized that can be used to obtain the friction coefficient between the contacting surfaces. By applying this model to the continuum damage mechanics model, the wear coefficient between dry surfaces is predicted. One of the advantages of using this model is that the wear coefficient can be numerically predicted unlike other methods which highly rely on experimental data. In order to verify the results predicted by this model, tests were performed using pin-on-disk test rig for several ST37 samples. The results indicated that the wear coefficient increases with increasing the friction coefficient.

Life Prediction of High Temperature Welded Component by Skeletal Point Rupture Stress

2010 ◽  
Vol 118-120 ◽  
pp. 156-160 ◽  
Author(s):  
Guo Dong Zhang ◽  
Yan Fen Zhao ◽  
Fei Xue ◽  
Zhao Xi Wang ◽  
Chang Yu Zhou
Keyword(s):  
High Temperature ◽  
Life Prediction ◽  
Power Plants ◽  
Damage Mechanics ◽  
Welded Joint ◽  
Stress Rupture ◽  
Continuum Damage Mechanics ◽  
Chemical Plants ◽  
Continuum Damage ◽  
Rupture Stress

At the present time, as the steam conditions and capability of the supercritical power unit increasing, the unit reliability is an important factor for the unit efficiency. High temperature, thick walled pipes are widely used in power plants and chemical plants. In this paper, life of the welded joint was predicted by the methods of skeletal point (SP) rupture stress rupture stress, which was calculated by finite element method (FEM). For the life prediction of welded component, the continuum damage mechanics was employed too. The life prediction of the welded joint by SP rupture stress was compared with the life prediction by the method of continuum damage mechanics (CDM). The research results showed that the two predicted methods were consistent. So, it can be concluded that the SP rupture stress can be used for predicting life of the high temperature welded component. The SP rupture stress method was used conveniently for the structure of power plant or other high temperature components.

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]

The Frost Model of Concrete in the View of Damage Mechanics

2011 ◽  
Vol 194-196 ◽  
pp. 919-923 ◽  
Author(s):  
Dong Fang Pan ◽  
Yun Feng Qiao ◽  
Cheng Shuai Sun ◽  
Xue Bing Liu
Keyword(s):  
Plastic Deformation ◽  
Damage Mechanics ◽  
Damage Model ◽  
Continuum Damage Mechanics ◽  
Dissipation Function ◽  
Continuum Damage ◽  
Thawing Cycle ◽  
Frost Model ◽  
Elastic Modules ◽  
The Continuum

To propose the damage model of concrete in the freezing-thawing cycles, the reasonable dissipation function and micro plastic deformation expression have been determined based on the continuum damage mechanics. The damage variable is expressed as a function of the number of freezing-thawing cycle. The damage is defined in terms of the loss of the dynamic elastic modules and the damage model of the concrete in the freezing-thawing cycles has been presented.

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