Cumulative Damage Models and Multi-Stress Fatigue Life Prediction

Hwang, Woonbong; Han, Kap Su

doi:10.1177/002199838602000202

Cited by 247 publications

(120 citation statements)

References 12 publications

Supporting

Mentioning

116

Contrasting

Unclassified

Order By: Relevance

“…In the next damage propagation phase, the stiffness continues to decrease gradually, ranging from a few percent for unidirectionally reinforced carbon composites to several tens of percents for multidirectional glass laminates [6,7,8,9,10,11,12,13]. Furthermore, most onedimensional damage models for fibre-reinforced composites only account for the effect of damage on the stiffness [5,13,14,15,16,17,18,19,20,21,22,23,24]. As such, the main focus in the fatigue experiments described here is on the expected stiffness degradation and permanent deformation.…”

Section: Introductionmentioning

confidence: 99%

On the tension–tension fatigue behaviour of a carbon reinforced thermoplastic part I: Limitations of the ASTM D3039/D3479 standard

et al. 2011

View full text Add to dashboard Cite

Investigating the fatigue behaviour of a material often requires a lot of experiments in order to have statistically valid results. However, the number of successful fatigue experiments, meaning tab failure did not occur, can be significantly smaller than the total number of experiments. This manuscript studies the fatigue behaviour of a carbon fabric reinforced PPS using the specimen geometry proposed by the ASTM D3479/D3479M standard. As it turns out, all specimens failed in the tabbed section, meaning that fatigue life may be significantly underestimated and that the proposed geometry needs for improvement. Therefore, the main emphasis in this manuscript lies on the stiffness degradation and the permanent deformation of the material, rather than on the number of cycles till failure. It may be concluded that for the [(0°,90°)] 4s stacking sequence the material does not show significant stiffness reduction and that only limited permanent deformation is present. Furthermore, the material shows very brittle failure behaviour and the stress-span between infinite fatigue life and failure in a few dozen cycles is very narrow.

show abstract

Section: Introductionmentioning

confidence: 99%

On the tension–tension fatigue behaviour of a carbon reinforced thermoplastic part I: Limitations of the ASTM D3039/D3479 standard

et al. 2011

View full text Add to dashboard Cite

show abstract

“…Furthermore, most of these models ignore basic observability of their damage states (i.e., crack length) in practical, real-life situations (e.g., when the direct measurement of a crack size is impossible or impractical). Secondly, almost all statistical (cycle counting) damage models gloss over the role that the initial damage state has on the true life cycle of structures [6].…”

Section: Introductionmentioning

confidence: 99%

Dynamical systems approach to fatigue damage identification

Chelidze

Liu

2005

Journal of Sound and Vibration

View full text Add to dashboard Cite

In this paper, we present a dynamical systems approach to material damage identification. This methodology does not depend on knowledge of the particular damage physics of material fatigue. Instead, it provides experimental means to determine what are practically observable and observed facts of damage accumulation, thus making it possible to develop or experimentally verify appropriate damage evolution laws. A concept of phase space warping is used to develop new damage tracking feature vectors from measured time series through phase space reconstruction. These feature vectors provide critical information about the dimensionality of a damage process that was missing from an old scalar metric described in previous work. Damage identification is achieved by applying either proper orthogonal decomposition (POD) or smooth orthogonal decomposition (SOD) to these vectors. The method is experimentally validated using an elasto-magnetic system, in which a harmonically forced cantilever beam in a nonlinear magnetic field accumulates fatigue damage. Both damage identification methods yield a single active damage mode that shows power-law type monotonic trends, which is also consistent with a result obtained using the old scalar metric. These results are shown to be in good agreement with the Paris fatigue crack growth model during the time-period of macroscopic crack growth. Using this simple model, accurate time to failure predictions are shown well ahead of actual beam fracture. In addition, this identification scheme provides much needed insight into the dimensionality of incipient or early fatigue damage accumulation process, which is shown to be describable by only one scalar damage variable for this specific experiment.

show abstract

“…A typical analysis begins by assuming that fatigue damage is being induced by applying a dynamic stress level r under constant frequency, temperature, moisture content, etc. conditions [13]. In this case the darnage D can be written as a fhnction of the applied stress level r and the number of fatigue cycles,…”

Section: Wear-out Approach For Predicting Remaining Lifetimementioning

confidence: 99%

The wear-out approach for predicting the remaining lifetime of materials

Gillen

Celina

2000

Polymer Degradation and Stability

View full text Add to dashboard Cite

Failure models based on the Palmgren-Miner concept that material darnage is cumulative have been derived and used mainly for fatigue life predictions for metals and composite materials. Wexeview the principles underlying such models and suggest ways in which they may be best applied to polymeric materials in temperature environments. We first outline expectations when polymer degradation data can be rigorously time-temperature superposed over a given temperature range. For a step change in temperature after darnage has occurred at an initial temperature in this range, we show that the remaining lifetime at the second temperature should be linearly related to the aging time prior to the step. This predicted linearity implies that it should be possible to estimate the remaining and therefore the service lifetime of polymers by completing the aging at an accelerated temperature. We refer to this generic temperature-step method as the "Wear-out" approach. We next outline the expectations for Wear-out experiments when timetemperature superposition is invalid. Experimental Wear-out results are then analyzed for one material where time-temperature superposition is valid and for another where evidence suggests it is invalid. In analyzing the data, we introduce a procedure that we refer to as time-degradation superposition. This procedure not only utilizes all of the experimental data instead of a single point from each data set, but also allows us to determine the importance of any "interaction effects".

show abstract

Cumulative Damage Models and Multi-Stress Fatigue Life Prediction

Cited by 247 publications

References 12 publications

On the tension–tension fatigue behaviour of a carbon reinforced thermoplastic part I: Limitations of the ASTM D3039/D3479 standard

On the tension–tension fatigue behaviour of a carbon reinforced thermoplastic part I: Limitations of the ASTM D3039/D3479 standard

Dynamical systems approach to fatigue damage identification

The wear-out approach for predicting the remaining lifetime of materials

Contact Info

Product

Resources

About