Non-linear damage accumulation in Au-irradiated SrTiO3

2006 ◽  
Vol 251 (1) ◽  
pp. 127-132 ◽  
Author(s):  
Y. Zhang ◽  
W.J. Weber ◽  
V. Shutthanandan ◽  
S. Thevuthasan
Keyword(s):  
Damage Accumulation ◽  
Non Linear

scholarly journals Prediction of Ductile Damage and Fracture in the Single and Multi-stage Incremental Hole-flanging Process Using a New Damage Accumulation Law

2021 ◽  
Author(s):  
Seyyed Emad Seyyedi ◽  
Hamid Gorji ◽  
Mohammad Javad Mirnia ◽  
Mohammad Bhakhshi-Jooybari
Keyword(s):  
Damage Accumulation ◽  
Single Point ◽  
Alloy Sheet ◽  
Fracture Prediction ◽  
Fem Model ◽  
User Subroutine ◽  
Damage And Fracture ◽  
Multi Stage ◽  
Non Linear ◽  
Hole Flanging

Abstract Incremental hole-flanging (IHF) is a process in which a sheet with a pre-cut hole is flanged by the single point incremental forming (SPIF) process. Fracture prediction in IHF, such as SPIF, is associated with many challenges due to the deformation mechanisms. The purpose of this paper is to overcome the existing limitations and challenges, and thus, to predict accurately failure in single, and multi-stage IHF processes. To this end, the modified Mohr-Coulomb (MMC) criterion was implemented using an appropriate user subroutine in a finite element method (FEM) model. The AA6061-T6 aluminum alloy sheet, which has low formability, and is fractured from its free edges in the IHF process, was examined as an example. Initially, a linear damage accumulation law, in which the prediction error is high due to the non-linear stress and strain states in the IHF, was used to predict the fracture. Therefore, in the next step, a non-linear damage accumulation function was utilized. While the non-linear accumulation accurately predicts the single-stage IHF fracture, it is not able to predict the fracture well in the multi-stage IHF. It was observed that in multi-stage IHF, the rate of damage accumulation decreases with increasing the number of forming stages. Accordingly, a new non-linear damage accumulation rule was developed. Experimental and numerical results indicated acceptable accuracy of the proposed non-linear accumulation in the fracture prediction in the single and multi-stage IHF process.

Quantification of fatigue damage accumulation using non-linear ultrasound measurements

2007 ◽  
Vol 29 (9-11) ◽  
pp. 2032-2039 ◽  
Author(s):  
R ORUGANTI ◽  
R SIVARAMANIVAS ◽  
T KARTHIK ◽  
V KOMMAREDDY ◽  
B RAMADURAI ◽  
...  
Keyword(s):  
Fatigue Damage ◽  
Damage Accumulation ◽  
Fatigue Damage Accumulation ◽  
Ultrasound Measurements ◽  
Non Linear

Probabilistic Non-Linear Cumulative Fatigue Damage of the P355NL1 Pressure Vessel Steel

2016 ◽  
Author(s):  
José António Fonseca de Oliveira Correia ◽  
Abílio Jesus ◽  
Sergio Blasón ◽  
Miguel Calvente ◽  
Alfonso Fernández-Canteli
Keyword(s):  
Fatigue Damage ◽  
Pressure Vessel ◽  
Damage Accumulation ◽  
Probabilistic Approach ◽  
Synergetic Effect ◽  
Pressure Vessel Steel ◽  
Sequential Effects ◽  
Vessel Steel ◽  
Fatigue Damage Accumulation ◽  
Non Linear

Miner’s rule for fatigue damage accumulation does not address conveniently the sequential effects of the fatigue loading due to underloads or overloads though such effects need to be taken into account for specific applications using a convenient model. Non-conservative (unsafe) or over-conservative (non-economic) fatigue predictions may result from such a linear damage analysis. To overcome these limitations, non-linear damage approaches are being proposed in the literature, as for instance, the double linear damage rule (DLDR). Further, advanced probabilistic models, as an alternative to deterministic ones, are being currently applied to fatigue damage assessment under variable (random) amplitude loading, though without including, up to present, sequential effects on the damage accumulation. In this paper, the synergetic effect of applying a non-linear fatigue damage model based on the DLDR in conjunction with a probabilistic approach based on the p-S-N field is pursued allowing the above mentioned sequential effects to be incorporated into a probabilistic damage prediction. The proposed approach was tested with existing fatigue block loading data available for the P355NL1 pressure vessel steel.

scholarly journals Non-Linear Probabilistic Modification of Miner’s Rule for Damage Accumulation

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7335
Author(s):  
Łukasz Blacha
Keyword(s):  
Fatigue Life ◽  
Probability Distribution ◽  
Damage Accumulation ◽  
Normal Distributions ◽  
Damage Degree ◽  
Non Linear ◽  
Miner’S Rule ◽  
The Mean ◽  
Fatigue Life Analysis ◽  
Miner's Rule

A non-linear modification to Miner’s rule for damage accumulation is proposed to reduce the scatter between experimental fatigue life and fatigue life predicted according to the original Miner’s sum. Based on P-s-n probability distribution and design s-n curves, the modification satisfies the assumption of equality between the mean damage degree (at the critical level) and fatigue life random variables, which is not covered in the original formulation. The adopted formulation shows the discrepancies between the fatigue lives predicted according to the design s-n curves and the estimated probability distribution. It also proves that it is inappropriate to apply a normal distribution to fatigue life analysis and that the model becomes non-linear only for non-normal distributions. The predictions according to the established model were compared to the predictions obtained with Miner’s rule.

A Modified Model for Non-Linear Fatigue Damage Accumulation With Load Interaction Effects

2015 ◽  
Author(s):  
Zhaochun Peng ◽  
Hong-Zhong Huang ◽  
Huiying Gao ◽  
Zhiqiang Lv ◽  
Shun-Peng Zhu
Keyword(s):  
Experimental Data ◽  
Fatigue Damage ◽  
Damage Accumulation ◽  
Interaction Effects ◽  
Variable Amplitude Loading ◽  
Modified Model ◽  
Variable Amplitude ◽  
Fatigue Damage Accumulation ◽  
Non Linear ◽  
Damage Rule

In the case of variable amplitude loading, fatigue damage accumulation theory is closely related to loading histories, such as load sequences, load interactions, and so on. Due to the lack of load histories, there may be a large deviation with the reality for linear damage rule (Miner rule). Although many non-linear fatigue damage accumulation models can deal with the effect of load sequences, load interaction effect cannot be ignored and it plays an important role in damage accumulation behavior. This paper describes the damage evolution behavior based on nonlinear damage rule under variable amplitude loading. A new method to describe the load interaction effects is proposed, it is assumed that the load ratio between adjacent stress levels is used to present this phenomenon. Thereafter, the method is introduced to a non-linear damage model, and a modified model is developed to predict the residual lifetime. Four categories of experimental data sets from literatures are employed to investigate the validity of the proposed model. The results indicate that the modified model shows a good agreement between experimental data and theoretical results. It is also found that the modified model demonstrates an improvement in prediction accuracy over the primary model and Miner rule. Furthermore, the modified model can be easily implemented with the use of Wöhler curve only.

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