scholarly journals Life Prediction of SAE 1045 Carbon Steel Using the Acoustic Emission Parameter

2013 ◽  
Vol 471 ◽  
pp. 329-334
Author(s):  
M. Mohammad ◽  
Shahrum Abdullah ◽  
Nordin Jamaludin ◽  
O. Innayatullah
Keyword(s):  
Acoustic Emission ◽  
Fatigue Life ◽  
Carbon Steel ◽  
Life Prediction ◽  
Statistical Approach ◽  
Emission Parameter ◽  
Acoustic Emission Parameter ◽  
Good Potential ◽  
Number Of Cycles ◽  
Cycles To Failure

The competency of acoustic emission (AE) technique in order to predict the fatigue life of SAE 1045 carbon steel was discussed in this paper. The correlation of the AE parameter and the number of cycles to failure of the tested specimens were established via the statistical approach. In this paper, The AE hits were selected as the functional parameter. The fatigue life values were calculated using the strain-life approach of three models; Coffin-Manson, Smith-Watson Topper and Morrow. Both AE and strain signals used in the analysis were captured using the AE sensor and strain gauge that were attached to the specimen during the fatigue test. The results show that the AE technique has a good potential in assessing the fatigue life with the designed H-N curve (AE hits-number of cycles to failure curve).

A New Finite Element Approach to Biaxial Fatigue Life Prediction in Gas Turbine Engine

2010 ◽  
Author(s):  
Wasim Tarar ◽  
M.-H. Herman Shen
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Gas Turbine ◽  
Life Prediction ◽  
Gas Turbine Engine ◽  
Constitutive Law ◽  
Fatigue Life Prediction ◽  
Turbine Engine ◽  
Number Of Cycles ◽  
Cycles To Failure

High cycle fatigue is the most common cause of failure in gas turbine engines. Different design tools have been developed to predict number of cycles to failure for a component subjected to fatigue loads. An energy-based fatigue life prediction framework was previously developed in recent research for prediction of axial and bending fatigue life at various stress ratios. The framework for the prediction of fatigue life via energy analysis was based on a new constitutive law, which states the following: the amount of energy required to fracture a material is constant. A finite element approach for uniaxial and bending fatigue was developed by authors based on this constitutive law. In this study, the energy expressions that construct the new constitutive law are integrated into minimum potential energy formulation to develop a new QUAD-4 finite element for fatigue life prediction. The newly developed QUAD-4 element is further modified to obtain a plate element. The Plate element can be used to model plates subjected to biaxial fatigue including bending loads. The new QUAD-4 element is benchmarked with previously developed uniaxial tension/compression finite element. The comparison of Finite element method (FEM) results to existing experimental fatigue data, verifies the new finite element development for fatigue life prediction. The final output of this finite element analysis is in the form of number of cycles to failure for each element in ascending or descending order. Therefore, the new finite element framework can predict the number of cycles to failure at each location in gas turbine engine structural components. The new finite element provides a very useful tool for fatigue life prediction in gas turbine engine components. The performance of the fatigue finite element is demonstrated by the fatigue life predictions from Al6061-T6 aluminum and Ti-6Al-4V. Results are compared with experimental results and analytical predictions.

A New Hex-8 Finite Element for Gas Turbine Engine Fatigue Life Prediction

2011 ◽  
Author(s):  
Wasim Tarar ◽  
M.-H. Herman Shen
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Gas Turbine ◽  
Life Prediction ◽  
Gas Turbine Engine ◽  
Constitutive Law ◽  
Fatigue Life Prediction ◽  
Turbine Engine ◽  
Number Of Cycles ◽  
Cycles To Failure

High cycle fatigue is the major governing failure mode in aerospace structures and gas turbine engines. Different design tools are available to predict number of cycles to failure for a component subjected to fatigue loads. An energy-based fatigue life prediction framework was previously developed in recent research for prediction of axial, bending and torsional fatigue life at various stress ratios. The framework for the prediction of fatigue life via energy analysis was based on a new constitutive law, which states the following: the amount of energy required to fracture a material is constant. A 1-D ROD element for unixial fatigue, a BEAM element for bending fatigue and a QUAD-4 element for biaxial fatigue were developed by authors based on this constitutive law. In this study, the energy expressions that construct the new constitutive law are integrated into minimum potential energy formulation to develop a new HEX-8 BRICK finite element for fatigue life prediction. The newly developed HEX-8 BRICK element has 8 nodes and each node has 3 degrees of freedom (DOF) in x, y and z directions. This element is further modified to add the rotational and bending DOFs for application to real world three dimensional (3D) structures and components. HEX-8 BRICK fatigue finite element has capability to predict the number of cycles to failure for 3-D objects subjected to multiaxial stresses. The new HEX-8 element is benchmarked with previously developed uniaxial tension/compression finite element in order to verify the new development. The comparison of finite element method (FEM) results to existing experimental fatigue data, verifies the new finite element development for fatigue life prediction. The final output of this finite element analysis is in the form of number of cycles to failure for each element in ascending or descending order. Therefore, the new finite element framework can predict the number of cycles to failure at each location in gas turbine engine structural components. The new finite element provides a very useful tool for fatigue life prediction in gas turbine engine components as it provides a complete picture of fatiguing process. The performance of the HEX-8 fatigue finite element is demonstrated by comparison of life prediction results for A16061-T6 to previously developed multiaxial fatigue life prediction approach by the authors. Another set of comparison is made to results for type 304 stainless steel data.

A New Finite Element for Gas Turbine Engine Fatigue Life Prediction

2007 ◽  
Author(s):  
Wasim Tarar ◽  
Onome Scott-Emuakpor ◽  
M.-H. Herman Shen
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Fatigue Life ◽  
Gas Turbine ◽  
Life Prediction ◽  
Constitutive Law ◽  
Fatigue Life Prediction ◽  
Turbine Engine ◽  
Number Of Cycles ◽  
Cycles To Failure

An energy-based fatigue life prediction framework was previously developed by the authors [1–4] for prediction of axial and bending fatigue life at various stress ratios. The framework for the prediction of fatigue life via energy analysis was based on a new constitutive law, which states the following: the amount of energy required to fracture a material is constant. In this study, the energy expressions that construct the new constitutive law is integrated into minimum potential energy formulation to develop a new finite element for fatigue life prediction. The comparison of Finite element method (FEM) results to existing experimental fatigue data, verifies the new finite element method for fatigue life prediction. The final output of this finite element analysis is in the form of number of cycles to failure for each element in ascending or descending order. Therefore, the new finite element framework can provide the number of cycles to failure for each element in gas turbine engine structural components. The performance of the fatigue finite element is demonstrated by the fatigue life predictions from 6061-T6 aluminum and Ti-6Al-4V. Results are compared with experimental results and analytical predictions [1].

scholarly journals Acoustic Emission Evaluation of Fatigue Life Prediction for a Carbon Steel Specimen using a Statistical-Based Approach

2013 ◽  
Vol 55 (6) ◽  
pp. 487-495 ◽  
Author(s):  
Mazian Mohammad ◽  
Shahrum Abdullah ◽  
Nordin Jamaluddin ◽  
Othman Innayatullah
Keyword(s):  
Acoustic Emission ◽  
Fatigue Life ◽  
Carbon Steel ◽  
Life Prediction ◽  
Steel Specimen ◽  
Fatigue Life Prediction

A New Energy-Based Multiaxial Fatigue Life Prediction Procedure

2008 ◽  
Author(s):  
Wasim Tarar ◽  
Onome Scott-Emuakpor ◽  
M.-H. Herman Shen ◽  
Tommy George ◽  
Charles Cross
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Life Prediction ◽  
Equivalent Stress ◽  
Multiaxial Fatigue ◽  
Constitutive Law ◽  
Fatigue Life Prediction ◽  
Element Analysis ◽  
Number Of Cycles ◽  
Cycles To Failure

An energy-based fatigue life prediction framework was previously developed by the authors for prediction of axial and bending fatigue life at various stress ratios. The framework for the prediction of fatigue life via energy analysis was based on a new constitutive law, which states the following: the amount of energy required to fracture a material is constant. In this study, energy expressions that construct the constitutive law are equated in the form of total strain energy and the distortion energy dissipated in a fatigue cycle. The resulting equation is further evaluated to acquire the equivalent stress per cycle using energy based methodologies. The equivalent stress expressions are developed both for biaxial and multiaxial fatigue loads and are used to predict the number of cycles to failure based on previously developed prediction criterion. The equivalent stress expressions developed in this study are further used in a new finite element procedure to predict the fatigue life for two and three dimensional structures. The final output of this finite element analysis is in the form of number of cycles to failure for each element on a scale in ascending or descending order. Therefore, the new finite element framework can provide the number of cycles to failure at each location in gas turbine engine structural components. In order to obtain experimental data for comparison, an Al6061-T6 plate is tested using a previously developed vibration based testing framework. The finite element analysis is performed for Al6061-T6 aluminum and the results are compared with experimental results.

Fatigue Life of the Human Teeth: A Continuum Damage Approach

2019 ◽  
Vol 43 ◽  
pp. 1-19
Author(s):  
Theddeus Tochukwu Akano
Keyword(s):  
Fatigue Life ◽  
Damage Mechanics ◽  
Stress Amplitude ◽  
Continuum Damage Mechanics ◽  
Continuum Damage ◽  
Elastoplastic Model ◽  
Human Teeth ◽  
Proposed Model ◽  
Number Of Cycles ◽  
Cycles To Failure

Normal oral food ingestion processes such as mastication would not have been possible without the teeth. The human teeth are subjected to many cyclic loadings per day. This, in turn, exerts forces on the teeth just like an engineering material undergoing the same cyclic loading. Over a period, there will be the creation of microcracks on the teeth that might not be visible ab initio. The constant formation of these microcracks weakens the teeth structure and foundation that result in its fracture. Therefore, the need to predict the fatigue life for human teeth is essential. In this paper, a continuum damage mechanics (CDM) based model is employed to evaluate the fatigue life of the human teeth. The material characteristic of the teeth is captured within the framework of the elastoplastic model. By applying the damage evolution equivalence, a mathematical formula is developed that describes the fatigue life in terms of the stress amplitude. Existing experimental data served as a guide as to the completeness of the proposed model. Results as a function of age and tubule orientation are presented. The outcomes produced by the current study have substantial agreement with the experimental results when plotted on the same axes. There is a notable difference in the number of cycles to failure as the tubule orientation increases. It is also revealed that the developed model could forecast for any tubule orientation and be adopted for both young and old teeth.

scholarly journals Rapid fatigue life prediction for spot-welded joint of SUS301 L-DLT stainless steel and Q235B carbon steel based on energy dissipation

2018 ◽  
Vol 10 (11) ◽  
pp. 168781401881101 ◽  
Author(s):  
Yaliang Liu ◽  
Yibo Sun ◽  
Yang Sun ◽  
Hongji Xu ◽  
Xinhua Yang
Keyword(s):  
Stainless Steel ◽  
Fatigue Life ◽  
Carbon Steel ◽  
Energy Dissipation ◽  
Life Prediction ◽  
Welded Joint ◽  
Fatigue Behavior ◽  
Dissimilar Materials ◽  
Fatigue Life Prediction ◽  
Spot Welded

Spot welding of dissimilar materials can utilize the respective advantage comprehensively, of which reliable prediction of fatigue life is the key issue in the structure design and service process. Taking into account almost all the complex factors that have effects on the fatigue behavior such as load level, thickness, welding nugget diameter, vibrational frequency, and material properties, this article proposed an energy dissipation-based method that is able to predict the fatigue life for spot-welded dissimilar materials rapidly. In order to obtain the temperature gradient, the temperature variations of four-group spot-welded joint of SUS301 L-DLT stainless steel and Q235 carbon steel during high-cycle fatigue tests were monitored by thermal infrared scanner. Specifically, temperature variation disciplines of specimen surface were divided into four stages: temperature increase, temperature decrease, continuous steady increase in temperature, and ultimate drop after the fracture. The material constant C that a spot-welded joint of dissimilar material needs to reach fracture is 0.05425°C·mm3. When the specimen was applied higher than the fatigue limit, the highest error between experimental values and predicted values is 18.90%, and others are lower than 10%. Therefore, a good agreement was achieved in fatigue life prediction between the new method and the validation test results.

scholarly journals Characterisation of fatigue damage in composites using an Acoustic Emission Parameter Correction Technique

2018 ◽  
Vol 151 ◽  
pp. 237-244 ◽  
Author(s):  
Safaa Kh Al-Jumaili ◽  
Mark J. Eaton ◽  
Karen M. Holford ◽  
Matthew R. Pearson ◽  
Davide Crivelli ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Fatigue Damage ◽  
Correction Technique ◽  
Emission Parameter ◽  
Acoustic Emission Parameter ◽  
Parameter Correction
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