Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
4.9
2.6
Journals
Metals
Special Issues
Microstructure, Deformation, and Fatigue Behavior in Metals
share announcement

Microstructure, Deformation, and Fatigue Behavior in Metals

A special issue of Metals (ISSN 2075-4701). This special issue belongs to the section "Metal Failure Analysis".

Deadline for manuscript submissions: closed (30 April 2021) | Viewed by 36685

Special Issue Editor

Prof. Dr. Ali Mehmanparast

E-Mail Website
Guest Editor
Department of Naval Architecture, Ocean and Marine Engineering, University of Strathclyde, Glasgow G1 1XQ, UK
Interests: fatigue design; corrosion–fatigue interactions; fractures; life prediction; structural integrity
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Metallic materials are widely used in fabrication of many components and structures operating in the harsh environments. These engineering structures, many of which are made of welded components, are often subjected to severe loading conditions causing fatigue, creep, fracture, and/or environmental damage that can eventually lead to failure. Some examples are high-temperature components used in power plants and offshore wind turbines operating in a harsh marine environment. An ongoing challenge in the design and life assessment of metallic structures is to provide a reliable estimation of the remaining life by considering realistic contributing factors in damage nucleation and evolution, including the material’s microstructure, deformation, crack initiation, and propagation. In this Special Issue, we seek to provide a wide set of articles on various aspects of metallic material degradation and failure mechanisms in the context of structural design, integrity, and reliability engineering. The idea is to address a broad range of issues which cause damage and failure in metallic structures. It is hoped that this open-access Special Issue will provide a platform for knowledge transfer between industrial and academic experts with the current state-of-the-art for the design and life assessment of metallic structures. Articles on the materials and microstructures, structural life assessment, risk and reliability engineering, and O&M of steel structures and additive manufacturing technologies are desired. Experimental, numerical, and analytical studies with significant contribution to knowledge are equally encouraged for publication in this Special Issue.

Dr. Ali Mehmanparast
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Metals is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Damage mechanisms
  • Fatigue and corrosion fatigue
  • Environmental assisted cracking
  • Structural design and integrity
  • Welded components
  • Materials engineering
  • Multiscale finite element modelling

Benefits of Publishing in a Special Issue

  • Ease of navigation: Grouping papers by topic helps scholars navigate broad scope journals more efficiently.
  • Greater discoverability: Special Issues support the reach and impact of scientific research. Articles in Special Issues are more discoverable and cited more frequently.
  • Expansion of research network: Special Issues facilitate connections among authors, fostering scientific collaborations.
  • External promotion: Articles in Special Issues are often promoted through the journal's social media, increasing their visibility.
  • e-Book format: Special Issues with more than 10 articles can be published as dedicated e-books, ensuring wide and rapid dissemination.

Further information on MDPI's Special Issue polices can be found here.

Published Papers (8 papers)

Download All Papers
Order results
Result details
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:

Research

Jump to: Review

13 pages, 5732 KiB  
Article
Proposal of Fatigue Limit Design Curves for Additively Manufactured Ti-6Al-4V in a VHCF Regime Using Specimens with Artificial Defects
by Yoshihiko Uematsu, Toshifumi Kakiuchi, Yaodong Han and Masaki Nakajima
Metals 2021, 11(6), 964; https://doi.org/10.3390/met11060964 - 15 Jun 2021
Cited by 8 | Viewed by 2845
Abstract
Cantilever-type rotating bending fatigue tests were conducted under a very high cycle fatigue regime using conventionally manufactured Ti-6Al-4V specimens having drilled artificial defects with different sizes. The relationship between fatigue limit and defect size was defined as a fatigue limit design curve considering [...] Read more.
Cantilever-type rotating bending fatigue tests were conducted under a very high cycle fatigue regime using conventionally manufactured Ti-6Al-4V specimens having drilled artificial defects with different sizes. The relationship between fatigue limit and defect size was defined as a fatigue limit design curve considering the transition from the fracture-mechanics dominating area to the fatigue-limit dominating area. A conventional Murakami’s equation was applicable as a design curve of additively manufactured Ti-6Al-4V with defects at 107 cycles. However, conventional equation gave un-conservative predictions for the fatigue limit at 108 cycles. Therefore, two kinds of modified Murakami’s equation were proposed as fatigue limit design curves for the very high cycle fatigue regime. Simple parallel shift of Murakami’s equation gave a conservative fatigue limit, whilst better result was obtained by changing the slope of Murakami’s equation. The proposed design curve was valid for the defect sizes ranging from 10 to 500 μm. Full article
(This article belongs to the Special Issue Microstructure, Deformation, and Fatigue Behavior in Metals)
►▼ Show Figures

Figure 1

13 pages, 16301 KiB  
Article
Remanufacturing the AA5052 GTAW Welds Using Friction Stir Processing
by Ghasem Azimi Roeen, Sajjad Ghatei Yousefi, Rahmatollah Emadi, Mohsen Shooshtari and Saeid Lotfian
Metals 2021, 11(5), 749; https://doi.org/10.3390/met11050749 - 1 May 2021
Cited by 14 | Viewed by 2518
Abstract
Progress in sustainable manufacturing is a crucial element to minimise negative environmental impacts. The conventional fusion weld process used to join aluminium alloys resulted in coarse grain structure, inevitable defects, and severe joint softening. Friction stir processing (FSP) has the potential to modify [...] Read more.
Progress in sustainable manufacturing is a crucial element to minimise negative environmental impacts. The conventional fusion weld process used to join aluminium alloys resulted in coarse grain structure, inevitable defects, and severe joint softening. Friction stir processing (FSP) has the potential to modify the microstructure of materials in joint structure and improve the mechanical properties. In this investigation, the effect of friction stir post–processing was evaluated to study the microstructural characteristics and mechanical properties of GTAW (gas tungsten arc welding) welds in the aluminium 5052 alloy. During FSP, the grains’ dendritic microstructure was destroyed, and the dynamic recrystallisation resulted in a very fine and equiaxed grains structure in the fusion zone. The hardness of the friction-stir-processed welds significantly improved because of microstructure grain refinement. The processed joint demonstrated higher ultimate tensile and yield strength (~275 MPa and 221 MPa, respectively) and superior elongation (31.1%) compared to the unprocessed weld; at the same time, the mechanical strength (yield and ultimate tensile) is similar to that of the base metal. Full article
(This article belongs to the Special Issue Microstructure, Deformation, and Fatigue Behavior in Metals)
►▼ Show Figures

Figure 1

14 pages, 3022 KiB  
Article
Experimental and Numerical Analysis of Fatigue Life of Aluminum Al 2024-T351 at Elevated Temperature
by Shahan Mazlan, Noorfaizal Yidris, Seyed Saeid Rahimian Koloor and Michal Petrů
Metals 2020, 10(12), 1581; https://doi.org/10.3390/met10121581 - 26 Nov 2020
Cited by 18 | Viewed by 4381
Abstract
This paper presents the prediction of the fatigue life of aluminum Al 2024-T351 at room and elevated temperatures under uniaxial loading using finite element simulation. Structural parts such as fuselage, wings, aircraft turbines and heat exchangers are required to work safely at this [...] Read more.
This paper presents the prediction of the fatigue life of aluminum Al 2024-T351 at room and elevated temperatures under uniaxial loading using finite element simulation. Structural parts such as fuselage, wings, aircraft turbines and heat exchangers are required to work safely at this working condition even with decreasing fatigue strength and other properties. The monotonic tensile and cyclic tests at 100 °C and 200 °C were conducted using MTS 810 servo hydraulic equipped with MTS 653 high temperature furnace at a frequency of 10 Hz and load ratio of 0.1. There was an 8% increase in the yield strength and a 2.32 MPa difference in the ultimate strength at 100 °C. However, the yield strength had a 1.61 MPa difference and 25% decrease in the ultimate strength at 200 °C compared to the room temperature. The mechanical and micro-structural behavior at elevated temperatures caused an increase in the crack initiation and crack propagation which reduced the total fatigue life. The yield strength, ultimate strength, alternating stress, mean stress and fatigue life were taken as the input in finite element commercial software, ANSYS. Comparison of results between experimental and finite element methods showed a good agreement. Hence, the suggested method using the numerical software can be used for predicting the fatigue life at elevated temperature. Full article
(This article belongs to the Special Issue Microstructure, Deformation, and Fatigue Behavior in Metals)
►▼ Show Figures

Figure 1

14 pages, 7510 KiB  
Article
Experimental Characterization of Tool Wear Morphology and Cutting Force Profile in Dry and Wet Turning of Titanium Metal Matrix Composites (Ti-MMCs)
by Masoomeh Safavi, Marek Balazinski, Hedayeh Mehmanparast and Seyed Ali Niknam
Metals 2020, 10(11), 1459; https://doi.org/10.3390/met10111459 - 31 Oct 2020
Cited by 6 | Viewed by 2437
Abstract
Metal-matrix composites (MMCs) are made of non-metallic reinforcements in metal matrixes, which have excellent hardness, corrosion, and wear resistance. They are also lightweight and may pose a higher strength-to-weight ratio as compared to commercial titanium alloys. One of the MMCs with remarkable mechanical [...] Read more.
Metal-matrix composites (MMCs) are made of non-metallic reinforcements in metal matrixes, which have excellent hardness, corrosion, and wear resistance. They are also lightweight and may pose a higher strength-to-weight ratio as compared to commercial titanium alloys. One of the MMCs with remarkable mechanical properties are titanium metal matrix composites (Ti-MMCs), which are considered a replacement for super-alloys in many industrial products and industries. Limited machining and machinability studies of Ti-MMCs were reported under different cutting and lubrication conditions. Tool wear morphology and life are among the main machinability attributes with limited attention. Therefore, this study presents the effects of cutting and lubrication conditions on wear morphology in carbide inserts when turning Ti-MMCs. To that end, maximum flank wear (VB) and cutting forces were recorded, and the wear morphologies within the initial period of the cut, as well as the worn condition, were studied under dry and wet conditions. Experimental results denoted that despite the lubrication mode used, abrasion, diffusion, and adhesion mechanisms were the main wear modes observed. Moreover, built-up layer (BUL) and built-up edge (BUE) were the main phenomena observed that increase the tendency of adhesion at higher cutting times. Full article
(This article belongs to the Special Issue Microstructure, Deformation, and Fatigue Behavior in Metals)
►▼ Show Figures

Figure 1

19 pages, 9318 KiB  
Article
Effect of Strain Rate on the Deformation Behaviour of A356-T7 Cast Aluminium Alloys at Elevated Temperatures
by Elanghovan Natesan, Johan Ahlström, Swathi K. Manchili, Stefan Eriksson and Christer Persson
Metals 2020, 10(9), 1239; https://doi.org/10.3390/met10091239 - 15 Sep 2020
Cited by 7 | Viewed by 3206
Abstract
Internal combustion engine downsizing and powertrain electrification trends in recent years have led to higher thermal loads on the cylinder head materials with an increased number of engine start–stop thermal load cycles. This requires designing cylinder heads that are resilient against thermomechanical fatigue [...] Read more.
Internal combustion engine downsizing and powertrain electrification trends in recent years have led to higher thermal loads on the cylinder head materials with an increased number of engine start–stop thermal load cycles. This requires designing cylinder heads that are resilient against thermomechanical fatigue damage. To reduce the developmental costs, reliable numerical models for use in computer-aided design approaches are required. Thus, a comprehensive understanding of the material deformation behaviour under loads mimicking in-service conditions is desired to make better engineering decisions. This study examines the effect of strain rate on the cyclic deformation behaviour of the A356-T7 + 0.5% Cu aluminium alloy commonly used in modern internal combustion engine cylinder heads. Samples extracted from the valve bridge areas of the cylinder heads are tested in strain-controlled fatigue tests. Samples are tested at strain rates of 1% s−1 and 10% s−1 at room temperature, 150 and 200 °C. The material exhibits increased isotropic hardening and softening rates and an increased number of cycles to failure at 10% s−1. The strain rate has a dramatic influence on the mean stress development at room temperature. The role of silicon particles in the fracture mechanism is investigated using electron microscopy techniques. Full article
(This article belongs to the Special Issue Microstructure, Deformation, and Fatigue Behavior in Metals)
►▼ Show Figures

Figure 1

14 pages, 5466 KiB  
Article
Numerical Analysis of Stress Distribution in Offshore Wind Turbine M72 Bolted Connections
by Raquel Redondo and Ali Mehmanparast
Metals 2020, 10(5), 689; https://doi.org/10.3390/met10050689 - 24 May 2020
Cited by 12 | Viewed by 6254
Abstract
The use of bolted joints to connect the transition piece and monopile is nowadays widely applied in the offshore wind industry. Traditionally, grouted connections were used in the early generation of offshore wind turbines, but the experienced failures in such connections led to [...] Read more.
The use of bolted joints to connect the transition piece and monopile is nowadays widely applied in the offshore wind industry. Traditionally, grouted connections were used in the early generation of offshore wind turbines, but the experienced failures in such connections led to an increased tendency towards bolted flange connections to join the transition piece and monopile in the new generation of offshore wind turbines. The bolts used for this purpose have high strength and huge sizes, and are subjected to a preload that is applied during the tightening process. The present study is focused on the analysis of preload effects on stress distribution in M72 bolted connections by considering different friction coefficients between the bolt and nut threads. The bolt is considered to be made of grade 10.9 steel, whereas the nut is assumed to be made of grade 8.8 steel, which is a softer material. Using the finite element commercial software package Abaqus, numerical models were developed and analysed to establish trends for stress distribution and plastic strains during the bolt tightening process, and to quantify stress concentration factors in individual engaged threads. Full article
(This article belongs to the Special Issue Microstructure, Deformation, and Fatigue Behavior in Metals)
►▼ Show Figures

Figure 1

Review

Jump to: Research

37 pages, 2174 KiB  
Review
A Systematic Review of Structural Reliability Methods for Deformation and Fatigue Analysis of Offshore Jacket Structures
by Abdulhakim Adeoye Shittu, Athanasios Kolios and Ali Mehmanparast
Metals 2021, 11(1), 50; https://doi.org/10.3390/met11010050 - 28 Dec 2020
Cited by 34 | Viewed by 5043
Abstract
This paper presents the state of the art in Structural Reliability Analysis (SRA) methods with a view of identifying key applications of each method and its proposed variations, qualifying characteristics, advantages, and limitations. Due to the increasing complexity and scale of modern offshore [...] Read more.
This paper presents the state of the art in Structural Reliability Analysis (SRA) methods with a view of identifying key applications of each method and its proposed variations, qualifying characteristics, advantages, and limitations. Due to the increasing complexity and scale of modern offshore jacket structures, it becomes increasingly necessary to propose an accurate and efficient approach for the assessment of uncertainties in their material properties, geometric dimensions, and operating environments. SRA, as a form of uncertainty analysis, has been demonstrated to be a useful tool in the design of structures because it can directly quantify how uncertainty about input parameters can affect structural performance. Herein, attention was focused specifically on the probabilistic fracture mechanics approach because this accounts accurately for fatigue reliability mostly encountered as being dominant in the design of such structures. The well-established analytical/approximate methods such as the First- and Second-Order Reliability Methods (FORM/SORM) are widely used as they offer a good balance between accuracy and efficiency for realistic problems. They are, however, inaccurate in cases of highly non-linear systems. As a result, they have been modified using methods such as conjugate search direction approach, saddle point approximation, subset simulation, evidence theory, etc. in order to improve accuracy. Initially, direct simulations methods such as the Monte Carlo Simulation Method (MCS) with its various variance reduction techniques such as the Importance Sampling (IS), Latin Hypercube Sampling (LHS), etc. are ideal for structures having non-linear limit states but perform poorly for problems that calculate very low probabilities of failure. Overall, each method has its own merits and limitation, with FORM/SORM being the most commonly used, but recently, simulation methods have increasingly been used due to continuous advances in computation powers. Other relevant methods include the Response Surface Methods (RSM) and the Surrogate Models/Meta-models (SM/MM), which are advanced approximation methods and are ideal for structures with implicit limit state functions and high-reliability indices. Combinations of advanced approximation methods and reliability analysis methods are also found in literature as they can be suitable for complex, highly non-linear problems. Full article
(This article belongs to the Special Issue Microstructure, Deformation, and Fatigue Behavior in Metals)
►▼ Show Figures

Figure 1

19 pages, 2748 KiB  
Review
A Review of Challenges and Opportunities Associated with Bolted Flange Connections in the Offshore Wind Industry
by Ali Mehmanparast, Saeid Lotfian and Sukumara Pillai Vipin
Metals 2020, 10(6), 732; https://doi.org/10.3390/met10060732 - 1 Jun 2020
Cited by 36 | Viewed by 8729
Abstract
The use of bolted flange connections in the offshore wind industry has steeply risen in the last few years. This trend is because of failings observed in other modes of joints such as grouted joints, coupled with enormous economic losses associated with such [...] Read more.
The use of bolted flange connections in the offshore wind industry has steeply risen in the last few years. This trend is because of failings observed in other modes of joints such as grouted joints, coupled with enormous economic losses associated with such failures. As many aspects of bolted flange connections for the offshore wind industry are yet to be understood in full, the current study undertakes a comprehensive review of the lessons learned about bolted connections from a range of industries such as nuclear, aerospace, and onshore wind for application in offshore wind industry. Subsequently, the collected information could be used to effectively address and investigate ways to improve bolted flange connections in the offshore wind industry. As monopiles constitute an overwhelming majority of foundation types used in the current offshore wind market, this work focusses on large diameter flanges in the primary load path of a wind turbine foundation, such as those typically found at the base of turbine towers, or at monopile to transition piece connections. Finally, a summary of issues associated with flanges as well as bolted connections is provided, and insights are recommended on the direction to be followed to address these concerns. Full article
(This article belongs to the Special Issue Microstructure, Deformation, and Fatigue Behavior in Metals)
►▼ Show Figures

Figure 1

Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying articles 1-8
Back to TopTop