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The focus of manufacturing is more and more on innovative and application-oriented products considering lightweight construction. Hence, especially functional graded materials come to the fore. Due to the application-matched functional…
The influence of fiber orientation on the crack propagation behavior was studied with single edgenotched specimens which were cut from an injection-molded plate of short-fiber reinforced plastics of polyphenylenesulphide (PPS) reinforced…
While a long stable crack propagation phase was observed during experiments of complex welded components, very conservative assessments of the fatigue life were achieved in the past. The difference was explained by the stress gradient…
In this paper, crack propagation in Advanced Gas-cooled Reactor (AGR) graphite bricks with ageing properties is studied using the eXtended Finite Element Method (X-FEM). A parametric study for crack propagation, including the influence of…
A three-dimensional crack propagation simulation is performed by the Dual Boundary Element Method (DBEM). The Stress Intensity Factors (SIFs) along the front of a semi elliptical crack, initiated from the external surface of a hollow axle…
Crack propagation in gears is a problem related not only to the life of the components, but also to the concept of failsafe design. Fail safe design means to design a component in order that, if a failure occurs, this may cause a “safe…
The fatigue crack propagation is one of the major problems and of the real concern in the evaluation of the structural integrity of components. This is due to the fact that once a fatigue crack has been detected it is also known its effect…
In this study, multiple and non-planar crack propagation analyses are performed using Fracture and Crack Propagation Analysis System (FCPAS). In an effort to apply and validate FCPAS procedures for multiple and non-planar crack propagation…
Fretting fatigue experiments aim to represent industrial problems and most of them endure variable loading. Being able to assess lifetime of assemblies, especially for low propagation rate conditions, is essential as experimental…
A class of fatigue crack growth models based on elastic–plastic stress–strain histories at the crack tip region and local strain-life damage models have been proposed in literature. The fatigue crack growth is regarded as a process of…
The investigation of fatigue strength of lotus-type structure with nodular cast iron as a base material using computational model is analysed in present study. The irregular pores distribution in transversal and longitudinal direction…
Additive layer manufacturing has recently gained a lot of interest due to the feasibility of producing metallic components directly from a computer-aided design file of the part. Selective laser melting, one of the main additive layer…
Titanium alloy (Ti-6Al-4V) having a bimodal “harmonic structure”, which consists of coarsegrained structure surrounded by a network structure of fine grains, was fabricated by mechanical milling (MM) and spark plasma sintering (SPS) to…
Crack propagation simulation began with the development of the finite element method; the analyses were conducted to obtain a basic understanding of the crack growth. Today structural and materials engineers develop structures and…
The initiation and propagation of fatigue cracks during cyclic torsion loading was studied in a cast Al alloy (A357) with a relatively large (~500 ?m) grain size. 2D observations, revealed that multi site crack initiation occur on the…
Brittle fracture in carbon steel has a serious impact on the safety of steel structures. Thus, technology that arrests crack propagation is the final line of protection for such structures. It is such an important issue that conditions…
Considerable efforts have been made over the last decades to improve performance of spring steels, which would increase the service time of springs and also allow vehicles weight reduction. There are different possibilities of improving…
Engine components are usually subject to complex loading patterns such as mixed-mode Low Cycle Fatigue Loading due to maneuvering. In practice, this LCF Loading has to be superimposed by High Cyclic Fatigue Loading caused by vibrations.…
During the last years many researchers put so much effort to design layered structures combining different materials in order to improve low fracture toughness and mechanical reliability of the ceramics. It has been proven, that an…
Thin rimmed and webbed gears are used in particular applications to reduce systems weight. This kind of gears need an accurate and fail safe design. As a matter of fact, a possible failure, due to bending fatigue, consists in crack…
In rolling contact fatigue (RCF), cracks usually initiate from inclusions beneath the surface and propagate to the contact surface. In the present study, synchrotron radiation computed laminography (SRCL) imaging was performed to observe…
The objective of the present paper is to clarify the effect of defect length in depth direction on rolling contact fatigue (RCF) crack propagation in high strength steel. RCF test and synchrotron radiation micro computed tomography (SR…
In the present article, a review of the complete characterization in different aggressive media of a Ti-6Al-4V titanium alloy, performed by the Structural Mechanics Laboratory of the University of Bergamo, is presented. The light alloy has…
The simulation of critical and subcritical crack propagation in heterogeneous materials is not a simple problem in computational mechanics. These topics can be studied with different theoretical tools. In the crack propagation problem it…
The specimen fractures appearances are analyzed to investigate the effects of mean tensile stress on the fatigue crack initiation and early propagation plane orientation under axial-torsion fatigue loading for 2A12T4 aluminum alloy. The…
The fivefold symmetric modular stellarator Wendelstein 7-X (W7-X) is currently under construction in Greifswald, Germany. The superconducting coils of the magnet system are bolted onto a central support ring and interconnected with five…
This work presents a review of crack propagation simulation models considering plane stress and plane strain conditions. It is presented also a chronological different methodologies used to perform the crack advance by finite element…
During fatigue crack propagation experiments with constant force as well as constant stress intensity lock in thermography and heat flow measurements with a new developed peltier sensor have been performed. With lock in thermography space…
The presented work introduces a numerical parametric study on the crack propagation direction under mixed-mode conditions (mode I + II). It is conducted for the geometry of an eccentric asymmetric fourpoint bending of a single edge notched…
Under the hypothesis of a perfectly brittle phenomenon, avalanche triggering can be investigated numerically by means of Linear Elastic Fracture Mechanics (LEFM). Since, however, the real phenomenon is intrinsically dynamical, another…
Fatigue considerations often distinguish between fatigue crack nucleation and fatigue crack propagation. The current work presents a modeling approach utilizing one Fatigue Damage Indicator to treat both in a unified way. The approach is…
This study discusses an effect of additive elements on crack propagation behaviour for low-Ag contain Sn1.0Ag0.7Cu lead-free solders at high temperature. A cyclic push-pull loading tests for four kinds of Sn1.0Ag0.7Cu solders were…
The mechanical clinching process can be used for the load-bearing structures of thin-walled steel frame halls. Numerical simulation of crack propagation in a clinching joint using finite element method (FEM) software is an important tool…
This paper deals with the fatigue crack propagation behavior of rolled AZ31B magnesium alloy (grain size: approximately 40 ?m). Fatigue crack propagation tests were performed on single edge notched tension specimens at a stress ratio of R…
Isotactic polybutene-1 (i-PB1) is a polymer used for the manufacturing of pressurized pipes. In this work two grades of i-PB1 with a different degree of isotacticity have been investigated; they have been supplied by Basell Polyolefins.…
This paper presents two multiaxial fatigue life prediction models applied to a commercial dental implant. One model is called Variable Initiation Length Model and takes into account both the crack initiation and propagation phases. The…
Looking at the long-time behaviour of a dam, it is necessary to assume that the water can penetrate a possible crack washing away some components of the concrete. This type of corrosion reduces the tensile strength and fracture energy of…
Among the most promising models introduced in recent years, with which it is possible to obtain very useful results for a better understanding of the physical phenomena involved in the macroscopic mechanism of crack propagation, the one…
This work aims to study the crack propagation in 12%Cr steel for turbine disks. Creep Crack Growth (CCG) tests on CT specimens have been performed to define the proper fracture mechanics which describes the initiation of the crack…
From experimental and theoretical investigations it is known that cracks are sensitive to geometry, e.g., to the inclination angle to the load. A small deviation of a crack from the normal direction to a tensile load causes mixed mode…
This paper presents new analytical model of asymmetric mixed-mode bending (MMB) specimen of adhesively bonded pultruded GFRP joints. An easily applicable relationship for the calculation of the strain energy release rate of the asymmetric…
Crack closure influences fatigue crack growth rate and must be included in the design of components. Plasticity induced crack closure is intimately linked with the crack tip plastic deformation, which becomes residual as the crack…
The fictitious notch rounding concept is applied for the first time to V-notches with root hole subjected to in-plane mixed mode loading. Out-of-bisector crack propagation is taken into account. The fictitious notch radius is determined as…
In the present work, the damage propagation of a masonry arch induced by slow cyclic and dynamic loadings is studied. A two-dimensional model of the arch is proposed. A nonlocal damage-plastic constitutive law is adopted to reproduce the…
Crack initiation and propagation have been investigated on the polymeric material ABS (Acrylonitrile Butadiene Styrene), under ultrasonic fatigue testing. Three controlled actions were implemented in order to carry out fatigue tests at…
The influence of environmental medias on crack propagation of a structural steel at high and very high-cycle fatigue (VHCF) regimes is investigated based on the fatigue tests performed in air, water and 3.5% NaCl aqueous solution. Crack…
In this work, we study the propagation of elastic waves in elongated solids with an array of equallyspaced deep transverse cracks, focusing in particular on the determination of stop-bands. We consider solids with different types of…
The study deals with the effect of load history during threshold and fatigue crack propagation measurements in the near threshold regime. The compression pre cracking and the stepwise increasing load amplitude test was applied. The effects…
Phase-field models have become a powerful tool to simulate crack propagation. They regularize the fracture discontinuity and smooth the transition between the intact and the damaged regions. Based on the thermodynamic function and a…
The structures in service are subjected to loads whose amplitude varies most often over time. These differences in loading cycle levels will have a direct impact on the propagation of cracks that can lead to accelerations or slowdowns in…
