Showing papers on "Paris' law published in 2020"
TL;DR: In this paper, an eXtended defect zone (XDZ) describing the propensity for local plasticity during fatigue around a defect has been shown through numerical analysis to be a good indicator of the ranking of the threat to fatigue caused by differently located manufacturing defects.
192 citations
TL;DR: In this paper, a variational framework to model the fatigue behavior of brittle materials based on a phase-field approach to fracture is presented, where the standard regularized free energy functional is modified introducing a fatigue degradation function that effectively reduces the fracture toughness as a proper history variable accumulates.
148 citations
TL;DR: In this paper, a probabilistic life prediction framework for reinforced concrete (RC) structures is proposed, where the coupled effect of corrosion and fatigue deteriorates the performance of reinforced concrete structures.
Abstract: The coupled effect of corrosion and fatigue deteriorates the performance of reinforced concrete (RC) structures. This paper proposes a novel framework for the probabilistic life prediction ...
101 citations
TL;DR: In this paper, the effect of surface quality and sub-surface porosity on high cycle fatigue behavior of 17-4 precipitation hardening (PH) stainless steel (SS) fabricated using laser beam powder bed fusion (LB-PBF) process was investigated.
94 citations
TL;DR: In this article, the effects of build direction on tensile and fatigue performance of Ti6Al4V manufactured by the selective laser melting technique were designed and manufactured in three different build direction.
65 citations
TL;DR: In this article, the microstructural and mechanical evolution of friction stir welded 6061-T6 aluminum alloy, the influence of notch locations on impact and fatigue crack growth (FCG) behavior were evaluated.
52 citations
TL;DR: In this article, a review of the mechanisms controlled by microstructural features including grain size, grain misorientation, γ′ size and distribution on short and long FCG behavior in PM Ni-based superalloys is discussed.
52 citations
TL;DR: In this article, the authors present an alternative method within this work, where the driving force for the fatigue mechanism increases due to cyclic loading, which can be approximated by a linear law, namely the Miner's rule for damage accumulation.
Abstract: Phase field modeling of fracture has been in the focus of research for over a decade now. The field has gained attention properly due to its benefiting features for the numerical simulations even for complex crack problems. The framework was so far applied to quasi static and dynamic fracture for brittle as well as for ductile materials with isotropic and also with anisotropic fracture resistance. However, fracture due to cyclic mechanical fatigue, which is a very important phenomenon regarding a safe, durable and also economical design of structures, is considered only recently in terms of phase field modeling. While in first phase field models the material’s fracture toughness becomes degraded to simulate fatigue crack growth, we present an alternative method within this work, where the driving force for the fatigue mechanism increases due to cyclic loading. This new contribution is governed by the evolution of fatigue damage, which can be approximated by a linear law, namely the Miner’s rule, for damage accumulation. The proposed model is able to predict nucleation as well as growth of a fatigue crack. Furthermore, by an assessment of crack growth rates obtained from several numerical simulations by a conventional approach for the description of fatigue crack growth, it is shown that the presented model is able to predict realistic behavior.
51 citations
TL;DR: In this article, the authors investigated the grain size dependence of fatigue crack growth in nanocrystalline superelastic NiTi shape memory alloys (SMAs) with the average GS of 10, 30, 60 and 235 nm.
50 citations
29 Jan 2020
TL;DR: A review of current technology on the mechanical behavior of these materials can be found in this article, which is divided into the following chapters: (1) Introduction; (2) Monotonic Response; (3) Micromechanical Theories for Inelastic Fibrous Composite Materials; (4) Interfaces in Metal Matrix Composites; (5) Fatigue Failure Mechanisms in TMCs; (6) Fat fatigue and Thermomechanical Fatigue Life Prediction; (7) Creep Behavior of Fiber Reinforced Titanium Matrix Composite; (8)
Abstract: Because of their unique mix of properties and behavior in high-performance applications, Titanium Matrix Composites are presently the focus of special research and development activity. This new book presents a review of current technology on the mechanical behavior of these materials. Each chapter was prepared specifically for this new book by one or more specialists in this subject. This book is divided into the following chapters: (1) Introduction; (2) Monotonic Response; (3) Micromechanical Theories for Inelastic Fibrous Composite Materials; (4) Interfaces in Metal Matrix Composites; (5) Fatigue Failure Mechanisms in TMCs; (6) Fatigue and Thermomechanical Fatigue Life Prediction; (7) Creep Behavior of Fiber Reinforced Titanium Matrix Composites; (8) Fatigue Crack Growth; (9) Notch Strength of Titanium Matrix Composites; and (10) Micromechanical Analysis and Modeling.
48 citations
TL;DR: In this paper, the authors investigated the corrosion fatigue crack propagation mechanism of high-strength steel bar HRB400 in various corrosive environments and conducted Fatigue crack growth (FCG) tests.
Abstract: This paper investigated the corrosion fatigue crack propagation mechanism of high-strength steel bar HRB400 in various corrosive environments. Fatigue crack growth (FCG) tests were conducte...
TL;DR: In this paper, the fatigue behavior of Inconel 718 (IN718) fabricated through laser beam directed energy deposition (LB-DED) process was investigated, and the microstructure was characterized after fabrication, heat treatment, and fatigue tests at elevated temperature.
TL;DR: In this paper, the authors performed a numerical estimation of the fatigue behavior of an epoxy-based adhesive subjected to mixed mode loading conditions, where the mixed mode was split into the corresponding components of mode I and mode II.
TL;DR: In this article, a radial basis function artificial neural network (RBF-ANN) model has been developed to predict the fatigue crack growth behavior in different length scales, including the short and long crack regimes.
TL;DR: In this paper, an experimental study on fatigue fracture performance of rail steel which is used in Iran railway is presented, for this purpose, the fatigue, fracture toughness and fatigue is analyzed.
Abstract: The purpose of this paper is an experimental study on fatigue fracture performance of rail steel which is used in Iran railway. For this purpose, the fatigue, fracture toughness and fatigue...
TL;DR: In this article, the parameters of fatigue crack growth rate for Q355J2 steel exposed to air and seawater were presented using the Paris' law based on the stress intensity factor (SIF), J-integral, crack tip opening displacement (CTOD), and crack tip tip opening angle (CTOA).
TL;DR: In this paper, the authors examined fatigue-crack-growth behaviors of CoCrFeMnNi high-entropy alloys under as-fatigued and tensile-overloaded conditions using neutron-diffraction measurements coupled with diffraction peak-profile analyses.
TL;DR: The outcrossing rate formulated by the PHI2 method is sensitive to the reliability index of the first component of the two-component parallel system.
TL;DR: In this paper, a 3-D finite element model was developed to obtain residual stress field in the material and the effects of repeated LSP pattern on the residual stress was investigated numerically.
TL;DR: In this paper, a Zr-based BMG known as AMZ4 with composition Zr593Cu288Nb15Al104 was printed using a laser powder bed fusion (LPBF) technique.
Abstract: Laser additive manufacturing of bulk metallic glass (BMG) provides an effective bypassing of the critical casting thickness constraints that limit the size of components that can be produced; however, open questions remain regarding the resulting mechanical properties In this work, a Zr-based BMG known as AMZ4 with composition Zr593Cu288Nb15Al104 was printed using a laser powder bed fusion (LPBF) technique Micro X-ray computed tomography results together with electron microscopy imaging revealed porous processing defects in LPBF produced AMZ4 that led to a loss in tensile strength Fatigue crack growth studies revealed a fatigue threshold, ΔKth, of ∼133 MPa√m and a Paris law exponent of m = 114, which are relatively low values for metallic materials A KIC fracture toughness of 24−29 MPa√m was found for the LPBF BMG samples, which is much lower than the KQ of 97−138 MPa√m and KJIC of 158−253 MPa√m measured for the cast alloy with the same composition The lower fracture toughness of the laser processed AMZ4 was attributed to ∼75× higher dissolved oxygen in the structure when compared to the cast AMZ4 Despite the higher level of oxygen, the formation of oxide nanocrystals was not observed by transmission electron microscopy Oxygen induced toughness loss was confirmed by dissolving elevated concentrations of oxygen into cast AMZ4 rods, which led to a reduction in bending ductility and changes in the short-range order of the glass structure, as revealed by synchrotron X-ray diffraction
TL;DR: In this paper, a three-parameter double exponential model for fitting the fatigue crack growth curves (crack length vs the number of fatigue life cycles) is also proposed for both the mode I and mixed mode (I/II) loading conditions.
TL;DR: In this paper, a 3D nonlinear stress analysis model has been applied to estimate stress fields of the rail under the influence of periodic overloads, and the results of this model are used for fatigue crack growth and also to estimate the fatigue life in rails using boundary element method (BEM).
TL;DR: In this article, an acceleration scheme for cyclic simulations of phase-field damage models is presented to facilitate large-scale simulations of industrially relevant problems, and the model and its parameters are validated with additional measurements of the fatigue crack growth rate.
TL;DR: In this paper, the influence of orientation and temperature on fatigue short crack propagation behavior of Inconel 718 alloy was studied at both 25°C and 650°C by in-situ fatigue testing under scanning electron microscope.
TL;DR: In this article, the authors investigated the crack growth and fatigue life estimation of the optimized rivet joints in aluminum 2024 sheets numerically and experimentally using the Taguchi and finite element method (FEM).
TL;DR: In this paper, a 3D boundary element model was used to estimate the stress intensity factor (SIF) using the crack opening displacement (COD) approach in rail specimens and the crack growth rate was predicted utilizing the Forman-Newman-de Koning (FNK) model.
TL;DR: In this paper, the authors explored a novel LSF fabrication design to produce full colony microstructure via in-situ controlled growth, which leads to superior fatigue crack growth resistance.
TL;DR: In this article, the fatigue crack propagation is modeled using the Molecular Dynamics (MD) analysis based on the Embedded Atom Method (EAM), and the crack growth simulation is performed for the single-crystal and poly-crystalline specimens subjected to cyclic loading/unloading conditions, and the growth rate is investigated at the atomistic level.
TL;DR: By correlating the uniaxial tensile properties (UTP) with cyclic plastic parameters and developing a unified fatigue crack closure factor U suitable for broad stress ratios, a novel FCG model of improved LAPS (iLAPS) was formulated in terms of linear damage accumulation and Rice-Kujawski-Ellyin field as discussed by the authors.