A Modified Cumulative Damage Model for Fatigue Life Prediction under Variable Amplitude Loadings

2016 ◽  
Vol 853 ◽  
pp. 62-66 ◽  
Author(s):  
Peng Yue ◽  
Qiang Lei ◽  
Cheng Lin Zhang ◽  
Shun Peng Zhu ◽  
Hong Zhong Huang

To evaluate the fatigue damage accumulation and predict the residual life of components at different stress levels, this paper proposed a modified cumulative damage model based on the strain energy density parameter. Noting that mean stress and load interaction under uniaxial fatigue loading exhibit significant effects on fatigue damage accumulation and life prediction. According to this, a new model based on damaged stress model which considers the effects of mean stress and load interaction was presented in this paper. The proposed model was verified by using four experimental data sets of aluminium alloys and steels. The experimental results are compared with those of the Miner’s rule, damaged stress model (DSM) and damaged energy model (DEM). Results show that the proposed model agrees better with the experimental observations than others.

Author(s):  
Chen Shen ◽  
Abderrahim Talha ◽  
Adel Hamdi ◽  
Noureddine Benseddiq

Criteria of fatigue damage play a key role in life prediction of structures subjected to random loadings. In previous works, a cumulative damage model called damage stress model was developed. This model takes into account not only the loading history but also the nonlinear evolution of damage. Damage stress model improved its predictive capability of fatigue life for several materials such as steels and aluminum alloys. In this paper, a new approach of cumulative damage, based upon the damage stress model parameter, is investigated for different loading paths under finite life regime. To build the new damage indicator, the damage stress model parameter is coupled with an equivalent stress formulated via Sines, Dang Van and Robert fatigue criteria, respectively. The relevance of the proposed model is examined using series of biaxial tests performed on cruciform specimens made of an aluminum alloy. Several types of loadings composed of constant amplitude fatigue, cumulative fatigue with two/three blocks and repeated blocks were set up. Good agreement is highlighted when the prediction, obtained with the proposed model, is compared to our experimental data.


2021 ◽  
Vol 13 (2) ◽  
pp. 168781402199530
Author(s):  
Bixiong Huang ◽  
Shuci Wang ◽  
Shuanglong Geng ◽  
Xintian Liu

To more accurately predict the fatigue life of components under the action of random loads, it is necessary to explore the influence of the interaction between the load sequence and the load on the life prediction. Based on the Manson-Halford method and Corten-Dolan model, this paper establishes a fatigue cumulative damage model that takes into account both the load order and the interaction between loads, and also takes into account the loads near the fatigue limit. The fatigue life of mechanical parts under random load can be calculated through this model, which provides a theoretical basis for life prediction under random load spectrum. The fatigue life of mechanical parts under random load can be calculated through this model, which provides a theoretical basis for life prediction under random load spectrum. Comparing the calculation results of the proposed model with the results of Palmgren Miner, Manson-Halford method, and Corten-Dolan model, it is found that the fatigue damage model established can reasonably predict the fatigue life of parts. Comparison and verification of examples further prove the accuracy and reliability of the proposed model.


2018 ◽  
Author(s):  
DC Pham

A new 3D damage model is developed to predict the progressive failure and accumulated fatigue damage of woven fabric composite materials. Stress-based failure criteria are used to predict the damage initiation in x-tow, y-tow, and matrix constituent. An S-N based damage accumulation model is implemented to characterize the cycle dependent strength of the x- and y- fiber tows and matrix subjected to axial tension, compression, or in-plane share loading. A curve-fit non-linear shear model is also employed based on the static coupon test data of (+45/-45) woven fabric laminates. A static failure progression module is used to predict the damage and failure at the peak load prior to fatigue cycling. Stiffness degradation, fatigue damage accumulation, and failure mode detection are performed during the fatigue marching process. The developed user-defined material model for Abaqus features: 1) description of initial nonlinear shear before the damage initiation; 2) characterization of failure initiation based on a maximum stress criterion; and 3) performance of fatigue damage accumulation using a phenomenological model based on S-N test data. The predictive capabilities of the developed model are demonstrated using tension-tension fatigue of SYNCOGLAS R420 E-glass woven fabrics.


Author(s):  
L Yang ◽  
A Fatemi

This study examines the fatigue damage accumulation process associated with a commonly produced forged vanadium-based microalloyed (MA) steel and its comparison with its quenched and tempered (Q&T) counterpart at the same hardness level. The advantage of MA steels compared to the traditional Q&T steels is the elimination of the costly quenching and tempering processes. Completely reversed strain-controlled two-level block loading tests were conducted on smooth axial specimens at room temperature. Under multi-level block cycling, the two steels displayed different characteristics, though they showed similar behaviour in constant amplitude fatigue. Therefore, a key to successful assessment of fatigue damage accumulation under variable amplitude service loading is selection of an appropriate cumulative fatigue life prediction model which reflects the material's damage characteristics. The effectiveness of several cumulative fatigue damage models and their life prediction capabilities are evaluated using the experimental data.


2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Xu Xu ◽  
Qiwen Xue ◽  
Zhaoyu Ku ◽  
Hanlun Li ◽  
Jinxiu Hu

PurposeFor the difference of the change law of material memory performance and the influence of damage state on memory performance, this paper aims to establish a general model of fatigue damage accumulation based on dynamic residual S–N curve and material memory characteristics.Design/methodology/approachThis paper introduces the material memory characteristics, combined with the residual S–N curve method, and uses the exponential decay function of the load cycle to construct the material memory performance function. While considering the damage state, the loading order can be fully considered. The parameter d in the function not only represents the variation of the material's memory property, but also considers the influence of the damage state.FindingsAccording to the test data of welding joints of common materials, alloy materials and other materials, the validity and feasibility of the fatigue cumulative damage model constructed were verified. The numerical results show that under the grading load, the fatigue cumulative damage model can be used to predict the fatigue life of welded structures and has high prediction accuracy and more approximate to the actual experiment results. It can be directly applied to the fatigue life prediction and design of actual engineering welded structures.Originality/valueThe model not only considers the effect of damage state and loading order on damage accumulation, but also contains only one material parameter, which is easy to obtain. The prediction accuracy and engineering practicability of fatigue were significantly improved.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Huiying Gao ◽  
Hong-Zhong Huang ◽  
Shun-Peng Zhu ◽  
Yan-Feng Li ◽  
Rong Yuan

Many structures are subjected to variable amplitude loading in engineering practice. The foundation of fatigue life prediction under variable amplitude loading is how to deal with the fatigue damage accumulation. A nonlinear fatigue damage accumulation model to consider the effects of load sequences was proposed in earlier literature, but the model cannot consider the load interaction effects, and sometimes it makes a major error. A modified nonlinear damage accumulation model is proposed in this paper to account for the load interaction effects. Experimental data of two metallic materials are used to validate the proposed model. The agreement between the model prediction and experimental data is observed, and the predictions by proposed model are more possibly in accordance with experimental data than that by primary model and Miner’s rule. Comparison between the predicted cumulative damage by the proposed model and an existing model shows that the proposed model predictions can meet the accuracy requirement of the engineering project and it can be used to predict the fatigue life of welded aluminum alloy joint of Electric Multiple Units (EMU); meanwhile, the accuracy of approximation can be obtained from the proposed model though more simple computing process and less material parameters calling for extensive testing than the existing model.


1978 ◽  
Vol 45 (2) ◽  
pp. 246-250 ◽  
Author(s):  
J. L. Bogdanoff

A new history-dependent phenomenological model of cumulative damage is presented. It is a stochastic model. The model includes as an inherent part of its structure the major sources of variability encountered in fatigue and wear. The generality possessed by the model is much more in accord with the complexity of fatigue and wear processes than possessed by models in current use. It also implies that the frequent inaccuracies encountered in life prediction when using current models are not surprising and cannot be substantially reduced using such models.


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