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Sabrina Vantadori - One of the best experts on this subject based on the ideXlab platform.
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crack initiation and life estimation for 316 and 430 stainless steel specimens by means of a Critical Plane Approach
International Journal of Fatigue, 2020Co-Authors: Sabrina Vantadori, Camilla Ronchei, Andrea Carpinteri, Daniela Scorza, Andrea Zanichelli, Yuki Okamoto, Shunsuke Saito, Raimondo Luciano, Takamoto ItohAbstract:Abstract In the present paper, the fatigue behaviour of two stainless steels is analysed by employing the criterion by Carpinteri et al. Such a criterion has already been applied to many data related to different metals, but the novelty of this paper is its application to assess the results of experimental tests performed under HCF triaxial loading. Such experimental data, found in the literature, are related to hollow cylindrical dog-bone specimens made of both 316 and 430 stainless steel. The experimental results are compared with the analytical ones in terms of both fatigue lifetime and initial crack Plane orientation.
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Lifetime estimation for 316 stainless steel specimens by using a Critical Plane Approach
Procedia Structural Integrity, 2020Co-Authors: Sabrina Vantadori, Camilla Ronchei, Andrea Carpinteri, Daniela Scorza, Andrea Zanichelli, Yuki Okamoto, Shunsuke Saito, Takamoto ItohAbstract:Abstract The lifetimes of 316 stainless steel specimens are herein evaluated using the multiaxial Critical Plane-based criterion by Carpinteri et al. for high-cycle fatigue (HCF) loading with constant amplitude. In the present paper, the stress-based version of such a criterion is applied to assess the results of experimental tests under HCF triaxial loading, the hollow cylindrical dog-bone specimens being subjected to a quenching heat treatment. The analytical results of fatigue life and initial crack Plane orientation are compared with the experimental data.
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early fretting crack orientation by using the Critical Plane Approach
International Journal of Fatigue, 2018Co-Authors: Sabrina Vantadori, Giovanni Fortese, Gabriel Magalhaes Juvenal Almeida, Geovana Callasans Veras Pessoa, J.a. AraújoAbstract:Abstract In the present paper, the novel Critical direction method by Araujo et al. and the multiaxial Critical Plane-based criterion by Carpinteri et al. are combined together to estimate early crack orientation in configurations involving high stress gradients, as fretting fatigue configurations. More precisely, the first method is used to compute the input data for the second one, in terms of normal and shear stresses over a line with a characteristic length. The experimental data herein analysed are related to an Al7050 T7451 aluminium alloy, the fretting tests related to a cylinder-on-Plane configuration being performed by the Research Group of Fatigue, Fracture and Materials at the University of Brasilia. Results show that the estimated values of the crack initiation Plane fall in the interval defined by the mean experimental values and the standard deviation for each test configuration examined.
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Effect of spectral cross-correlation on multiaxial fatigue damage: simulations using the Critical Plane Approach
Frattura ed Integrità Strutturale, 2017Co-Authors: Andrea Carpinteri, Andrea Spagnoli, Sabrina VantadoriAbstract:The present paper aims to discuss a frequency-domain multiaxial fatigue criterion based on the Critical Plane Approach, suitable for fatigue life estimations in the presence of proportional and non-proportional random loading. The criterion consists of the following three steps: definition of the Critical Plane, Power Spectral Density (PSD) evaluation of an equivalent normal stress, and estimation of fatigue damage. Such a frequency-domain criterion has recently been validated by using experimental data available in the literature, related to combined proportional and non-proportional bending and torsion random loading. The comparison with such experimental data has been quite satisfactory. In order to further validate the above criterion, numerical simulations are herein performed by employing a wide group of combined bending and torsion signals. Each of such signals is described by an ergodic, stationary and Gaussian stochastic process, with zero mean value. The spectrum of each signal is assumed to be represented by a PSD function with rectangular shape. Different values of correlation degree, variance and spectral content are examined.
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A Strain-based Multiaxial Fatigue Criterion Connected to the Critical Plane Approach
Procedia Engineering, 2014Co-Authors: Andrea Carpinteri, Camilla Ronchei, Andrea Spagnoli, Sabrina VantadoriAbstract:Abstract A Critical Plane-based high-cycle multiaxial fatigue criterion, known as the Carpinteri-Spagnoli (C-S) criterion, is here extended to evaluate the fatigue lifetime of plain metallic components under constant amplitude loading in the low/medium-cycle regime. An equivalent strain amplitude, computed through a quadratic combinations of strain components in the Critical Plane, is taken as the fatigue damage parameter. A validation by experimental data pertaining the biaxial fatigue of plain steel specimens under both proportional and non-proportional loadings is performed.
Andrea Carpinteri - One of the best experts on this subject based on the ideXlab platform.
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crack initiation and life estimation for 316 and 430 stainless steel specimens by means of a Critical Plane Approach
International Journal of Fatigue, 2020Co-Authors: Sabrina Vantadori, Camilla Ronchei, Andrea Carpinteri, Daniela Scorza, Andrea Zanichelli, Yuki Okamoto, Shunsuke Saito, Raimondo Luciano, Takamoto ItohAbstract:Abstract In the present paper, the fatigue behaviour of two stainless steels is analysed by employing the criterion by Carpinteri et al. Such a criterion has already been applied to many data related to different metals, but the novelty of this paper is its application to assess the results of experimental tests performed under HCF triaxial loading. Such experimental data, found in the literature, are related to hollow cylindrical dog-bone specimens made of both 316 and 430 stainless steel. The experimental results are compared with the analytical ones in terms of both fatigue lifetime and initial crack Plane orientation.
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Lifetime estimation for 316 stainless steel specimens by using a Critical Plane Approach
Procedia Structural Integrity, 2020Co-Authors: Sabrina Vantadori, Camilla Ronchei, Andrea Carpinteri, Daniela Scorza, Andrea Zanichelli, Yuki Okamoto, Shunsuke Saito, Takamoto ItohAbstract:Abstract The lifetimes of 316 stainless steel specimens are herein evaluated using the multiaxial Critical Plane-based criterion by Carpinteri et al. for high-cycle fatigue (HCF) loading with constant amplitude. In the present paper, the stress-based version of such a criterion is applied to assess the results of experimental tests under HCF triaxial loading, the hollow cylindrical dog-bone specimens being subjected to a quenching heat treatment. The analytical results of fatigue life and initial crack Plane orientation are compared with the experimental data.
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Multiaxial Fatigue Damage Assessment of Welded Connections in Railway Steel Bridge using Critical Plane Approach
Procedia Engineering, 2018Co-Authors: Praveen K R, S.s. Mishra, Prasad Babu, Andrea Spagnoli, Andrea CarpinteriAbstract:Abstract As the number of heavy railway traffic load increased, concern over the accurate and actual fatigue damage of the bridge is intensified. Especially for bridges which were designed for light traffic load. The fatigue damage assessment of steel bridge connections is usually based on notion of uniaxial S-N curves given in the codes of practice. Until now, there is no consensus on a method which can precisely consider non-proportional multiaxial loading. The objective of this paper is to examine the applicability and appropriateness of the Critical Plane Approach-based C-S criterion to perform the fatigue damage assessment in welded connections in railway steel bridge. A regular U trough railway steel bridge is analyzed using finite element software ANSYS 17.2 for standard railway traffic. The averaged principal stress directions determined through appropriate weight functions are used to orient the Critical Plane. Prediction of fatigue damage is performed through an equivalent stress represented by a quadratic combination of the normal and the shear stress components acting on the Critical Plane. Applicability of the C-S criterion is studied by assessing the fatigue damage of Critical welded connections and comparing with the λ - coefficient and cumulative damage method calculated according to Eurocode EN1993-1-9.
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Effect of spectral cross-correlation on multiaxial fatigue damage: simulations using the Critical Plane Approach
Frattura ed Integrità Strutturale, 2017Co-Authors: Andrea Carpinteri, Andrea Spagnoli, Sabrina VantadoriAbstract:The present paper aims to discuss a frequency-domain multiaxial fatigue criterion based on the Critical Plane Approach, suitable for fatigue life estimations in the presence of proportional and non-proportional random loading. The criterion consists of the following three steps: definition of the Critical Plane, Power Spectral Density (PSD) evaluation of an equivalent normal stress, and estimation of fatigue damage. Such a frequency-domain criterion has recently been validated by using experimental data available in the literature, related to combined proportional and non-proportional bending and torsion random loading. The comparison with such experimental data has been quite satisfactory. In order to further validate the above criterion, numerical simulations are herein performed by employing a wide group of combined bending and torsion signals. Each of such signals is described by an ergodic, stationary and Gaussian stochastic process, with zero mean value. The spectrum of each signal is assumed to be represented by a PSD function with rectangular shape. Different values of correlation degree, variance and spectral content are examined.
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A Strain-based Multiaxial Fatigue Criterion Connected to the Critical Plane Approach
Procedia Engineering, 2014Co-Authors: Andrea Carpinteri, Camilla Ronchei, Andrea Spagnoli, Sabrina VantadoriAbstract:Abstract A Critical Plane-based high-cycle multiaxial fatigue criterion, known as the Carpinteri-Spagnoli (C-S) criterion, is here extended to evaluate the fatigue lifetime of plain metallic components under constant amplitude loading in the low/medium-cycle regime. An equivalent strain amplitude, computed through a quadratic combinations of strain components in the Critical Plane, is taken as the fatigue damage parameter. A validation by experimental data pertaining the biaxial fatigue of plain steel specimens under both proportional and non-proportional loadings is performed.
Tadeusz łagoda - One of the best experts on this subject based on the ideXlab platform.
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a correction in the algorithm of fatigue life calculation based on the Critical Plane Approach
International Journal of Fatigue, 2016Co-Authors: Aleksander Karolczuk, Krzysztof Kluger, Tadeusz łagodaAbstract:Abstract The paper presents the algorithm for calculating the fatigue life taking into account the variability of coefficients occurring in the multiaxial fatigue criterion depending on the number of cycles to failure. The algorithm has been analysed under uniaxial cyclic loads and a combination of bending and torsion for four structural materials. Significant increase of convergence of calculated and experimental fatigue life using the new algorithm as compared to the classical Approach for five selected multiaxial fatigue criteria based on a Critical Plane has been demonstrated.
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fatigue life of aluminium alloy 6082 t6 under constant and variable amplitude bending with torsion
Journal of Theoretical and Applied Mechanics, 2015Co-Authors: Aleksander Karolczuk, Marta Kurek, Tadeusz łagodaAbstract:The paper presents the comparison of experimental and calculated fatigue lives for EN AW-6082 T6 aluminium alloy. Hour-glass shaped specimens have been subjected to constant and variable amplitude uniaxial and multiaxial loadings, i.e. Plane bending, torsion and their proportional combinations with zero mean values. Three multiaxial fatigue criteria based on the Critical Plane Approach have been verified being the linear combination of shear and normal stresses on the Critical Plane. For the variable-amplitude loading, the rainflow cycle counting method and Palmgren-Miner hypothesis have been applied. The best fatigue criteria are pointed in the final conclusions.
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lifetime of semi ductile materials through the Critical Plane Approach
International Journal of Fatigue, 2014Co-Authors: Karolina Walat, Tadeusz łagodaAbstract:Abstract This paper presents the results of fatigue strength estimation depending on the variable orientation of the Critical Plane for proportional and non-proportional bending and torsion with regard to specimens made of aluminium alloy 2017A. The algorithm applied for the fatigue strength evaluation is based on the Carpinteri–Spagnoli proposal and its subsequent modifications in accordance with the ideas developed by the authors. The objective of this paper is to search for a model which offers the best possible results of fatigue strength estimation for materials with properties which are intermediate between elastic-brittle and elastic–plastic, such as aluminium alloys, and a further insight into them with regard to their fatigue strength.
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a Critical Plane Approach based on energy concepts application to biaxial random tension compression high cycle fatigue regime
International Journal of Fatigue, 1999Co-Authors: Tadeusz łagoda, Ewald Macha, W BedkowskiAbstract:Abstract In this paper the energy parameter, defined for random loadings, is analysed. Under uniaxial loading this parameter distinguishes between the strain energy density for tension (positive) and the strain energy density for compression (negative). As a consequence, if there is no mean component in the random loading, we obtain a random history of strain (elastic and plastic) energy density with zero expected value. Under multiaxial loadings the normal strain energy density in the Critical Plane (i.e. the Plane of the maximum damage) is understood as the energy parameter. The history of strain energy density is schematized with use of the rain-flow algorithm. Fatigue damage is accumulated according to Palmgren-Miner hypothesis and the standard fatigue characteristic of the material, rescaled with use of the considered energy parameter. The proposed parameter was verified during fatigue tests of cruciform specimens made of 10HNAP steel, subjected to biaxial non-proportional random tension-compresion. The calculated fatigue lives are included in the scatter band of the experimental data of a factor of 3. Thus, the normal strain energy density in the Critical Plane seems to be an efficient fatigue parameter under random non-proportional loadings for high-cycle fatigue.
Takamoto Itoh - One of the best experts on this subject based on the ideXlab platform.
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crack initiation and life estimation for 316 and 430 stainless steel specimens by means of a Critical Plane Approach
International Journal of Fatigue, 2020Co-Authors: Sabrina Vantadori, Camilla Ronchei, Andrea Carpinteri, Daniela Scorza, Andrea Zanichelli, Yuki Okamoto, Shunsuke Saito, Raimondo Luciano, Takamoto ItohAbstract:Abstract In the present paper, the fatigue behaviour of two stainless steels is analysed by employing the criterion by Carpinteri et al. Such a criterion has already been applied to many data related to different metals, but the novelty of this paper is its application to assess the results of experimental tests performed under HCF triaxial loading. Such experimental data, found in the literature, are related to hollow cylindrical dog-bone specimens made of both 316 and 430 stainless steel. The experimental results are compared with the analytical ones in terms of both fatigue lifetime and initial crack Plane orientation.
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Lifetime estimation for 316 stainless steel specimens by using a Critical Plane Approach
Procedia Structural Integrity, 2020Co-Authors: Sabrina Vantadori, Camilla Ronchei, Andrea Carpinteri, Daniela Scorza, Andrea Zanichelli, Yuki Okamoto, Shunsuke Saito, Takamoto ItohAbstract:Abstract The lifetimes of 316 stainless steel specimens are herein evaluated using the multiaxial Critical Plane-based criterion by Carpinteri et al. for high-cycle fatigue (HCF) loading with constant amplitude. In the present paper, the stress-based version of such a criterion is applied to assess the results of experimental tests under HCF triaxial loading, the hollow cylindrical dog-bone specimens being subjected to a quenching heat treatment. The analytical results of fatigue life and initial crack Plane orientation are compared with the experimental data.
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On the Behaviour of 316 and 304 Stainless Steel under Multiaxial Fatigue Loading: Application of the Critical Plane Approach
Metals, 2019Co-Authors: A.s. Cruces, Pablo Lopez-crespo, Stefano Bressan, Takamoto Itoh, B MorenoAbstract:In this work, the multiaxial fatigue behaviour of 316 and 304 stainless steel was studied. The study was based on the Critical Plane Approach which is based on observations that cracks tend to nucleate and grow in specific Planes. Three different Critical Plane models were employed to this end, namely Fatemi–Socie (FS), Smith–Watson–Topper (SWT) and the newly proposed Sandip–Kallmeyer–Smith (SKS) model. The study allowed equi-biaxial stress state, mean strain and non–proportional hardening effects to be taken into consideration. Experimental tests including different combinations of tension, torsion and inner pressure were performed and were useful to identify the predominant failure mode for the two materials. The results also showed that the SKS damage parameter returned more conservative results than FS with lower scatter level in both materials, with prediction values between FS and SWT.
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Investigation of the Biaxial Behaviour of 316 Stainless Steel Based on Critical Plane Method
Key Engineering Materials, 2018Co-Authors: A.s. Cruces, Pablo Lopez-crespo, Stefano Bressan, B Moreno, Takamoto ItohAbstract:In this work the biaxial behavior of 316 stainless steel is studied under the lens of Critical Plane Approach. A series of ten experiments were developed on dog bone shape hollow cylindrical specimens made of type 316 stainless steel. Five different loading conditions were assessed, with (i) only axial stress, (ii) only hoop stress, (iii) proportional combination of axial and hoop stresses, (iv) non-proportional combination of axial and hoop stresses with square shape and (v) non-proportional combination of axial and hoop stresses with L-shape. The fatigue analysis is performed following four different Critical Plane theories, namely Wang-Brown, Fatemi-Socie, Liu I and Liu II. The efficiency of all four theories is studied in terms of the accuracy of their life predictions.
Ali Fatemi - One of the best experts on this subject based on the ideXlab platform.
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On the application of a Critical Plane Approach to the life assessment of welded joints
Procedia Engineering, 2018Co-Authors: Giuseppe Marulo, Francesco Frendo, Leonardo Bertini, Ali FatemiAbstract:Abstract In the present work, the Fatemi-Socie Approach is adopted in order to analyze the fatigue endurance of welded joints under multiaxial loads. This Critical Plane criterion has already been successfully applied to plain or notched components, however, it is not spread in the assessment of welded joints, yet. This work is focused on the practical implementation issues related to this particular application, which has not been discussed in the literature. The described procedure is adopted for the assessment of one hundred experimental tests and some preliminary results are shown. The specimen under investigation is a pipe-to-plate fillet joint made out of structural steel (S355JR). The tests were performed under both uniaxial and multiaxial, i.e. combined in-phase and out-of-phase bending and torsion, load conditions with a constant amplitude at the laboratories of the University of Pisa, Italy.
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multiaxial variable amplitude fatigue life analysis using the Critical Plane Approach part ii notched specimen experiments and life estimations
International Journal of Fatigue, 2017Co-Authors: Nicholas R Gates, Ali FatemiAbstract:Abstract While part I of this paper was focused on evaluating multiaxial variable amplitude fatigue life estimations for un-notched specimens, part II extends the same Critical Plane-based analysis procedures to situations involving notched specimens. In addition to the factors considered in the un-notched analyses, local stress concentrations, stress gradient effects, and changes in local stress state must also be accounted for in the presence of a notch. This was accomplished in the current study by coupling the Theory of Critical Distances point method with a pseudo stress-based plasticity modeling technique. Then, a modified version of the Fatemi-Socie parameter was used to calculate fatigue damage, and changes in life estimation accuracy were studied with respect to the consideration of transient material deformation behavior, crack initiation definition, and damage summation rule. Results from the notched specimen analyses were also compared to those for un-notched specimens, and some discussion is provided. While the effect of transient deformation behavior and crack initiation definition were found to be relatively small for the loading histories used in this study, changing the Critical damage sum at failure had a much greater impact on life estimations. Although some of the analysis procedures investigated were able to estimate nearly all fatigue lives within a factor of 3 of experimental results, several areas were identified where there is potential for even further improvements to be made. These include issues related to the accuracy of life estimation curves, damage calculation models, and/or the modeling of material deformation behavior.
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application of the Critical Plane Approach to the torsional fatigue assessment of welds considering the effect of residual stresses
International Journal of Fatigue, 2017Co-Authors: Kimiya Hemmesi, Majid Farajian, Ali FatemiAbstract:Abstract This study aims to investigate how the welding residual stresses affect the fatigue life of steel tubular joints. A single pass weld with filler material is created on the tubular specimens made of structural steel S355J2H. At first, welding residual stresses are calculated numerically by means of FE simulations. The validity of the results is verified experimentally by means of diffraction measurement techniques. Then, an uncoupled damage model based on the Critical Plane Approach is utilized in order to calculate the fatigue life and the initial crack orientation. The as-welded specimens were subjected to cyclic torsional loading with constant stress amplitudes. The Fatemi-Socie (FS) damage parameter is used which is interpreted as the cyclic shear strain damage modified by the normal stress to include the crack closure effect. The stable portion of welding residual stresses is accounted for by the normal stress term of the model. It was observed that despite the common understandings about the Critical weld notches, the crack initiation sites under torsional loading have been shifted from the weld toe and from the surface to the heat affected zone and beneath the surface where high tensile residual stresses exist. Then the initial cracks propagated toward the surface whose orientations were influenced by the presence of compressive residual stresses on the surface. It was generally found that the Fatemi-Socie parameter is capable of torsional fatigue damage assessment of welded tubular specimens which contain residual stresses since this Critical Plane parameter is based on the maximum shear strain Plane.