Multiaxial cycle counting for critical plane methods

Langlais, T

doi:10.1016/s0142-1123(02)00148-2

Cited by 66 publications

(55 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Small cracks can nucleate and growth on a "critical" plane where the maximum shear strain is attained; therefore the multi-axial damage assessment can be reduced to an uni-axial equivalent problem. Nevertheless normal stresses and shear strains can occur out of phase [23] and this makes cycle counting more difficult; moreover the orientation of the critical plane is generally unknown so, even if a proper counting algorithm is available, the damage assessment procedure must be repeated for several candidate critical orientations. Improved multi-axial cycle counting algorithms have been proposed [23]- [24] in order to cope with the effects mentioned above.…”

Section: Rainflow Counting For Random Loadingmentioning

confidence: 99%

“…Nevertheless normal stresses and shear strains can occur out of phase [23] and this makes cycle counting more difficult; moreover the orientation of the critical plane is generally unknown so, even if a proper counting algorithm is available, the damage assessment procedure must be repeated for several candidate critical orientations. Improved multi-axial cycle counting algorithms have been proposed [23]- [24] in order to cope with the effects mentioned above. In this paper the critical plane cycle counting is not considered because a scalar stress measure is introduced via a spectral representation of the von Mises stress; this allows reducing the multi-axial cycle counting to the much simpler random uni-axial scenario discussed above.…”

Section: Rainflow Counting For Random Loadingmentioning

confidence: 99%

See 1 more Smart Citation

On the inverse power laws for accelerated random fatigue testing

Allegri

Zhang

2008

International Journal of Fatigue

View full text Add to dashboard Cite

This paper addresses the usage of inverse power laws in accelerated fatigue testing under wide-band Gaussian random loading. The aim is not at predicting an absolute value of fatigue life but assessing the fatigue damage relative accumulation. The widely accepted inverse power scaling laws in fatigue damage assessment is discussed, reviewing the engineering standards and pointing out their inherent limitations. A physically consistent general scaling law is obtained by rigorous mathematical analysis in the framework of random vibration theory and the rules of safe-life fatigue analysis. Simplifications of the general scaling rule are presented, highlighting conditions under which the current standard practice could provide a correct an acceptable estimation of the relative fatigue damage accumulation.Key words: fatigue, inverse power law, random loading, cycle counting, accelerated testing Nomenclature T r -fatigue life in the operative environment;T s -fatigue life in the testing condition; g -acceleration root mean square value (RMS); g r -acceleration RMS in the operative environment;

show abstract

Section: Rainflow Counting For Random Loadingmentioning

confidence: 99%

Section: Rainflow Counting For Random Loadingmentioning

confidence: 99%

On the inverse power laws for accelerated random fatigue testing

Allegri

Zhang

2008

International Journal of Fatigue

View full text Add to dashboard Cite

show abstract

“…Shear-based damage models require a uniaxial rainflow count applied to the shear strain A (or stress A) acting on the candidate plane, while tensile-based damage models must count the normal strain (or stress ) perpendicular to such plane. The other stress and strain components can be regarded as auxiliary channels [7], which will provide the additional parameters needed by each multiaxial fatigue damage model, such as mean or maximum stresses.…”

Section: Critical Plane Rainflowmentioning

confidence: 99%

“…Note that, in addition to the use of either the stress ratio R min/ max or the mean m ( max min)/2 the main difference among the critical plane implementations of Liu's energy model is that the main rainflow channel is either for Case A Mode I tensile cracks, A for Case A Mode II shear cracks, or B for Case B Mode III shear cracks. A very efficient uniaxial rainflow algorithm that is capable of dealing with auxiliary channels has been proposed in [7]. It is based on the four-point rainflow algorithm [14], which is able to count very long histories in real time as the peaks and valleys are entered as input, without requiring an a priori knowledge of the entire load history.…”

Section: Critical Plane Rainflowmentioning

confidence: 99%

Invariant-based and Critical-plane Rainflow Approaches for Fatigue Life Prediction Under Multiaxial Variable Amplitude Loading

Meggiolaro

Castro

2015

Procedia Engineering

View full text Add to dashboard Cite

Multiaxial variable amplitude histories usually require a rainflow algorithm to identify individual cycles. A computationallyefficient 5D multiaxial rainflow algorithm that can deal with any 1D to 6D history has been proposed by the authors, based on the representation of 6D stresses and strains in 5D deviatoric sub-spaces that use a von Mises metric. These spaces provide simple geometric interpretations for the identified load cycles while highly reducing computational cost. In this work, the most efficient multiaxial rainflow algorithms for variable amplitude histories are presented and compared, detailing their individual advantages and disadvantages.

show abstract

“…Owing to the high costs associated with fatigue failures, since the beginning of the last century a tremendous effort has been made by the international scientific community to devise appropriate engineering tools suitable for estimating fatigue damage under complex loading paths. If attention is focused on the low/medium-cycle fatigue regime, examination of the state of the art [1][2][3][4][5][6][7] suggests that, so far, this intractable design problem has being addressed mainly by trying to extend the use of wellknown constant amplitude (CA) multiaxial fatigue criteria to those situations involving multiaxial VA load histories. In this context, among the methods which have been employed so far, certainly the SWT parameter [8,9], Brown & Miller's criterion [10,11], and Fatemi & Socie's critical plane approach [12,13] deserve to be mentioned explicitly.…”

Section: Introductionmentioning

confidence: 99%

The Modified Manson–Coffin Curve Method to estimate fatigue lifetime under complex constant and variable amplitude multiaxial fatigue loading

Wang

Susmel

2016

International Journal of Fatigue

View full text Add to dashboard Cite

This paper investigates the accuracy of the so-called Modified Manson-Coffin Curve Method (MMCCM) in estimating fatigue lifetime of metallic materials subjected to complex constant and variable amplitude multiaxial load histories. The MMCCM postulates that fatigue damage is maximised on that material plane experiencing the maximum shear strain amplitude. In the present investigation, the orientation of the critical plane was determined through that direction along which the variance of the resolved shear strain reaches it maximum value. Under variable amplitude complex load histories, this direction was also used to count the resolved shear strain cycles via the classic Rain-Flow method. Further, the degree of multiaxiality and nonproportionality of the time-variable stress states at the assumed critical locations was directly quantified through a suitable stress ratio which accounts for (i) the mean value and the variance of the stress perpendicular to the critical plane as well as for (ii) the variance of the shear stress resolved along the direction experiencing the maximum variance of the resolved shear strain. The accuracy and reliability of the proposed approach was checked against approximately 650 experimental data taken from the literature and generated by testing un-notched metallic materials under complex constant and variable amplitude multiaxial load histories. The sound agreement between estimates and experimental results which was obtained strongly supports the idea that the proposed design technique is a powerful engineering tool allowing metallic materials to be designed against constant and variable amplitude multiaxial fatigue by always reaching a remarkable level of accuracy. This approach offers a complete solution to the strain based multiaxial fatigue problem.

show abstract

Multiaxial cycle counting for critical plane methods

Cited by 66 publications

References 11 publications

On the inverse power laws for accelerated random fatigue testing

On the inverse power laws for accelerated random fatigue testing

Invariant-based and Critical-plane Rainflow Approaches for Fatigue Life Prediction Under Multiaxial Variable Amplitude Loading

The Modified Manson–Coffin Curve Method to estimate fatigue lifetime under complex constant and variable amplitude multiaxial fatigue loading

Contact Info

Product

Resources

About