Papers by Andrea Carpinteri
Theoretical and Applied Fracture Mechanics, Aug 1, 2020
Abstract This research work aims to provide computational remarks for the strength degradation an... more Abstract This research work aims to provide computational remarks for the strength degradation analysis of pre-existing random damages. By means of a novel fatigue-resistance design algorithm, the mixed mode I/II damages are investigated taking into account the effects of stress intensities and mean stresses. Analytical and numerical evaluations in terms of the residual life and crack path are successfully validated against relevant experiments under cyclic loading with constant amplitude and overload.
International Journal of Fatigue, Oct 1, 2019
This paper presents an investigation on the failure of plates with double-edge notches and fatigu... more This paper presents an investigation on the failure of plates with double-edge notches and fatigue damage. The main aim is to develop a computational model for estimating the behaviour of a quarter-elliptical corner crack or a through-the-thickness crack located at semicircular edge notch. In such an analytical/numerical analysis, driving forces are evaluated by means of an analytical model and the finite element method, whereas the fatigue life is assessed employing a stress ratio-dependent crack growth law and the stress intensity factor.
Theoretical and Applied Fracture Mechanics, Apr 1, 2017
The capability of materials to bear loads even in presence of defects like cracks, notches or gen... more The capability of materials to bear loads even in presence of defects like cracks, notches or generic geometric discontinuities is usually indicated as flaw tolerance, and is crucial in modern safety design of structural components. Such a tolerance capability can be remarkable in highly deformable materials (also called soft materials), usually much more pronounced than in conventional ones. The ability of highly deformable materials to undergo very large deformations before failure is mainly due to their noticeable rearrangement of the molecular network with a significant decrease of the internal entropic state. Neglecting such an entropic effect can lead to erroneous underestimations of the safety level against defect-driven failure. In the present research, the mechanics of highly deformable materials is discussed by examining silicone-based notched and cracked plates. Experimental, numerical and theoretical aspects of the involved phenomena are analyzed in order to provide an explanation of the mechanism of defect resistance in such a class of materials from a physics-based point-of-view.
Materials Science Forum, Mar 1, 2011
The aim of the present paper is to evaluate the effect of residual stresses, due to cold-drawing ... more The aim of the present paper is to evaluate the effect of residual stresses, due to cold-drawing process, on the fatigue crack propagation in a pearlitic steel wire with a V-shaped circumferential notch. In order to analyse the effect of the notch severity on the residual stress distribution, three different values of the notch root radius are examined. The residual stress distributions in the reduced cross-section of such wires are numerically evaluated through FE analyses which simulate the material removing operation in the notched region. The stress-intensity factors (SIFs) related to tension loading and residual stresses are computed. Then, the crack propagation under cyclic tension combined with the residual stresses is analysed by taking into account the above SIF values and the actual stress ratio, which is different from that due to cyclic tension only.
Fatigue & Fracture of Engineering Materials & Structures, Apr 1, 1992
The crack propagation of a semi-elliptical surface flaw subjected to cyclic combined axial and be... more The crack propagation of a semi-elliptical surface flaw subjected to cyclic combined axial and bending loadings with constant amplitude is numerically examined according to Paris-Erdogan law. The critical crack, for which a given number of cycles is necessary to cause fatigue failure, can be determined from interaction between the theoretical results obtained and the experimental data of the Wohler curves. Some examples are presented for different stress ranges ACT, and loading eccentricities given by e = M/F, where F and M are the axial force and the bending moment, respectively.
Engineering Fracture Mechanics, 1991
ABSTRACT
Procedia structural integrity, 2019
The description of a problem related to an evolving interface or a strong discontinuity requires ... more The description of a problem related to an evolving interface or a strong discontinuity requires to solve partial differential equations on a moving domain, whose evolution is unknown. Standard computational methods tackle this class of problems by adapting the discretized domain to the evolving interface, and that creates severe difficulties especially when the interface undergoes topological changes. The problem becomes even more awkward when the involved domain changes such as in mechanical problems characterized by large deformations. In this context, the phase-field approach allows us to easily reformulate the problem through the use of a continuous field variable, identifying the evolving interface (i.e. the crack in fracture problems), without the need to update the domain discretization. According to the variational theory of fracture, the crack grows by following a path that ensures that the total energy of the system is always minimized. In the present paper, we take advantage of such an approach for the description of fracture in highly deformable materials, such as the so-called elastomers. Starting from a statistical physics-based micromechanical model which employs the distribution function of the polymer's chains, we develop herein a phase-field approach to study the fracture occurring in this class of materials undergoing large deformations. Such a phase-field approach is finally applied to the solution of crack problems in elastomers.
Fatigue & Fracture of Engineering Materials & Structures, Jan 29, 2019
The damage estimation for a structure under random loading is a challenge in fatigue assessment, ... more The damage estimation for a structure under random loading is a challenge in fatigue assessment, especially when the loading is multiaxial. The comparison of the effect of different spectra on fatigue damage is essential when the structure can be subjected to different types of loadings. Therefore, in the present paper, the expected fatigue damage produced on metallic structures by combined bending and torsion stationary proportional and nonproportional loading is evaluated varying the shape of spectra of the normal and shear stress tensor components.
Procedia Engineering, 2014
In the present paper, fatigue crack propagation in V-notched round bars under cyclic eccentric ax... more In the present paper, fatigue crack propagation in V-notched round bars under cyclic eccentric axial loading is numerically evaluated using both a finite element analysis and an automated numerical model proposed by the first author. The stressintensity factors are computed at a set of points on the crack front by the finite element method. Then, a suitable fatigue crack growth law is applied to the above set of points. By varying the loading eccentricity value and the notch root geometry, several initial semi-elliptical surface crack configurations are analysed.
Applied sciences, May 27, 2019
In the present paper, the fatigue life assessment of notched structural components is performed b... more In the present paper, the fatigue life assessment of notched structural components is performed by applying a critical plane-based multiaxial fatigue criterion. Such a criterion is formulated by using the control volume concept related to the strain energy density criterion. The verification point is assumed to be at a given distance from the notch tip. Such a distance is taken as a function of the control volume radii around the notch tip under both Mode I and Mode III loading. The accuracy of the present criterion is evaluated through experimental data available in the literature, concerning titanium alloy notched specimens under uniaxial and multiaxial fatigue loading.
Procedia Engineering, 2014
A critical plane-based high-cycle multiaxial fatigue criterion, known as the Carpinteri-Spagnoli ... more 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.
Theoretical and Applied Fracture Mechanics, Apr 1, 2019
Nowadays, research on sustainable buildings is devoted to materials which offer advantages in ter... more Nowadays, research on sustainable buildings is devoted to materials which offer advantages in terms of recyclability, low cost, environmentally-friendly features, no toxicity, biodegradability and good mechanical performance. The lightweight 3
Computational Materials Science, Feb 1, 2009
Based on high-resolution digital images of High Performance Concrete (HPC) microstructures, a two... more Based on high-resolution digital images of High Performance Concrete (HPC) microstructures, a twodimensional mesoscopic lattice model which accounts for fatigue damage is proposed. Fatigue damage is introduced by considering the coupled effects of loading cycles and tensile strain on stiffness degradation of microstructural lattice elements under fatigue loading. The ultimate tensile strain is defined as the failure threshold value for microstructural lattice elements. Further, the effects of the lattice element properties (i.e. size and finite element type) and fatigue loading parameters (i.e. stress levels) on the damage mechanisms of the HPC microstructure are investigated and discussed. It is found that lattice truss elements 1 mm long are satisfactory, giving also their smaller computational requirements in comparison to beam counterparts, to investigate fatigue damage in the HPC microstructure. The numerical results of the present model are consistent with experimental observations.
International Journal of Fatigue, May 1, 2009
ABSTRACT
Fatigue & Fracture of Engineering Materials & Structures, Jul 4, 2023
In the present paper, the fracture toughness of a polyurethane (PUR) foam (manufactured by Necume... more In the present paper, the fracture toughness of a polyurethane (PUR) foam (manufactured by Necumer GmbH, Germany, under the commercial designation Necuron 651) is experimentally and numerically investigated in order to examine its dependence on the specimen sizes. As a matter fact, to the best knowledge of the present authors, such an analysis is still missing in the technical literature. To perform the experimental campaign, notched PUR foam beams, with different geometrical sizes, are tested under three‐point bending loading, and the Modified Two‐Parameter Model (recently proposed by some of the present authors) is employed to measure the fracture toughness. Subsequently, such an experimental campaign is numerically simulated by applying a micromechanical model, implemented in a non‐linear finite element homemade code. Finally, the results obtained are compared with some experimental data available in the literature, related to the same PUR foam.
Zenodo (CERN European Organization for Nuclear Research), Aug 2, 2021
Abstract In the present paper, the fatigue behaviour of two Ductile Cast Irons (DCIs) is analyzed... more Abstract In the present paper, the fatigue behaviour of two Ductile Cast Irons (DCIs) is analyzed. Both infinite and finite life fatigue tests are simulated by employing the Carpinteri et al. criterion. Such tests, found in the literature, are related to DCI smooth specimens subjected to proportional and non-proportional constant amplitude cyclic loadings. The theoretical results are compared with the experimental ones in terms of both fatigue endurance and fatigue life.
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Papers by Andrea Carpinteri