Submit to Special Issue Submit Abstract to Special Issue Review for Materials Propose a Special Issue

Journal Browser

Special Issue "Damage Analysis for Composite Materials: Methods, Testing and Evaluation"

Print Special Issue Flyer
Special Issue Editors
Special Issue Information
Keywords
Published Papers

A special issue of Materials (ISSN 1996-1944). This special issue belongs to the section "Advanced Materials Characterization".

Deadline for manuscript submissions: 20 February 2024 | Viewed by 4133

Share This Special Issue

Special Issue Editors

Prof. Dr. Luís Miguel Pereira Durão

E-Mail Website
Guest Editor

Department of Mechanical Engineering, Instituto Superior de Engenharia do Porto, Porto, Portugal
Interests: composites; machining; damage onset and propagation; damage assessment; image processing; non-destructive testing; mechanical testing

Dr. Nuno Calçada Loureiro

E-Mail Website
Guest Editor

Department of Industrial Production Engineering, Instituto Superior de entre Douro e Vouga, Santa Maria da Feira, Portugal
Interests: biodegradable composites; green composites; mechanical characterization; production technologies; damage assessment

Special Issue Information

Dear Colleagues,

After the stone, the bronze, and the iron ages, material history is now in the composites age. Thanks to their unique characteristics, composites are widely used in the production of parts for a large number of final products.

In the production process of composite parts, circular hole drilling may be necessary to allow their assembly and incorporation into complex sets, using screws, bolts, pins, rivets or snap springs. These operations are currently carried out by machining, as drilling is widely used. In the drilling process, delamination is the most frequent damage and can reduce the load-bearing capacity of the parts.

The optimization of drilling parameters, the development of specific tool geometries, and the consequences in terms of damage caused by machining have been extensively studied recently. However, there are still some open issues addressing damage extension assessment and the outcomes on load bearing capacity and fatigue behavior that deserve research and discussion.

This Special Issue is intended to act as a contributor to this discussion and to future developments on this theme.

The analysis of the damage propagation process in these materials and damage evaluation methods based on data extracted via image processing of holes machined in composites are of prime importance. Normally, the machined holes are analyzed by different NDT (Non-Destructive Testing) based on visual inspection, microscopy, digital enhanced radiography, ultrasound, active and passive thermography, laser shearography, and digital image correlation. The images resulting from the NDT are processed by diverse means to establish a numerical assessment of the damage. The use of NDTs and the correlation between damage extension and bearing load properties is a major driving theme that will be deeply discussed in this Special Issue.

It is our pleasure to invite you to submit a manuscript for this Special Issue. Full papers, communications, and reviews are all welcome.

Prof. Dr. Luís Miguel Pereira Durão
Dr. Nuno Calçada Loureiro
Guest Editors

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. Materials is an international peer-reviewed open access semimonthly 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

composites
machining
tool design
damage onset and propagation
image processing
NDT techniques
damage assessment
damage modeling
mechanical testing

Published Papers (7 papers)

Download All Papers

Research

Open AccessArticle

Damage Detection in a Polymer Matrix Composite from 4D Displacement Field Measurements

and

Materials 2023, 16(18), 6300; https://doi.org/10.3390/ma16186300 - 20 Sep 2023

Viewed by 249

Abstract

Standard Digital Volume Correlation (DVC) approaches enable quantitative analyses of specimen deformation to be performed by measuring displacement fields between discrete states. Such frameworks are thus limited by the number of scans (due to acquisition duration). Considering only one projection per loading step, Projection-based Digital Volume Correlation (P-DVC) allows 4D (i.e., space and time) full-field measurements to be carried out over entire loading histories. The sought displacement field is decomposed over a basis of separated variables, namely, temporal and spatial modes. In the present work, the spatial modes are constructed via scan-wise DVC, and only the temporal amplitudes are sought via P-DVC. The proposed method is applied to a glass fiber mat reinforced polymer specimen containing a machined notch, subjected to in situ cyclic tension and imaged via X-ray Computed Tomography. The P-DVC enhanced DVC method employed herein enables for the quantification of damage growth over the entire loading history up to failure. Full article

(This article belongs to the Special Issue Damage Analysis for Composite Materials: Methods, Testing and Evaluation)

► Show Figures

Figure 1

Open AccessArticle

Micro-Scale Numerical Simulation of Fatigue Failure for CFRP Subjected to Multiple-Amplitude Cyclic Loadings Based on Entropy Damage Criterion

and

Materials 2023, 16(18), 6120; https://doi.org/10.3390/ma16186120 - 07 Sep 2023

Viewed by 242

Abstract

Fatigue failure of carbon fiber-reinforced plastics (CFRPs) under cyclic loadings has attracted the attention of researchers recently. In this study, the entropy-based failure criterion is proposed to investigate the fatigue lifetime of unidirectional CFRPs subjected to multiple-amplitude cyclic loadings. Due to the heterogeneity of CFRPs, a micro-finite element model considering matrix resin and fibers independently is developed, and the entropy-based damage criterion is implemented into a user-subroutine of Abaqus to model the progressive damage of matrix resin. The fatigue lifetime of CFRPs under typical loading sequences consisting of two stages, such as varying from low to high (L-H) or from high to low (H-L) loading sequence, is estimated with the proposed failure criterion. Numerical results show that the initial damage occurs near the area between two fibers, and a transverse crack propagates progressively under the cyclic loading. The difference in predicted lifetime to final failure in L-H and H-L stress levels is 6.3%. Thus, the effect of loading sequence on the fatigue lifetime can be revealed via the proposed entropy-based damage criterion. Comparisons with the conventional linear cumulative damage (LCD) and kinetic crack growth (KCG) theories are also conducted to demonstrate the validity of the proposed method. The entropy-based failure criterion is a promising method to predict the residual strength and fatigue lifetime of CFRP components. Full article

(This article belongs to the Special Issue Damage Analysis for Composite Materials: Methods, Testing and Evaluation)

► Show Figures

Figure 1

Open AccessArticle

Damage Assessment of Glass-Fibre-Reinforced Plastic Structures under Quasi-Static Indentation with Acoustic Emission

Norman Osa-uwagboe

Amadi Gabriel Udu

Vadim V. Silberschmidt

Konstantinos P. Baxevanakis

and

Emrah Demirci

Materials 2023, 16(14), 5036; https://doi.org/10.3390/ma16145036 - 17 Jul 2023

Viewed by 572

Abstract

The use of fibre-reinforced plastics (FRPs) in various industrial applications continues to increase thanks to their good strength-to-weight ratio and impact resistance, as well as the high strength that provides engineers with advanced options for the design of modern structures subjected to a variety of out-of-plane impacts. An assessment of the damage morphology under such conditions using non-destructive techniques could provide useful data for material design and optimisation. This study investigated the damage mechanism and energy-absorption characteristics of E-glass laminates and sandwich structures with GFRP face sheets with PVC cores under quasi-static indentation with conical, square, and hemispherical indenters. An acoustic emission (AE) technique, coupled with a k-means++ pattern-recognition algorithm, was employed to identify the dominant microscopic and macroscopic damage mechanisms. Additionally, a post-mortem damage assessment was performed with X-ray micro computed tomography and scanning electron microscopy to validate the identified clusters. It was found that the specific energy absorption after impact with the square and hemispherical indenters of the GFRP sandwich and the plain laminate differed significantly, by 19.29% and 43.33%, respectively, while a minimal difference of 3.5% was recorded for the conical indenter. Additionally, the results obtained with the clustering technique applied to the acoustic emission signals detected the main damaged modes, such as matrix cracking, fibre/matrix debonding, delamination, the debonding of face sheets/core, and core failure. The results therefore could provide a methodology for the optimisation and prediction of damage for the health monitoring of composites. Full article

(This article belongs to the Special Issue Damage Analysis for Composite Materials: Methods, Testing and Evaluation)

► Show Figures

Figure 1

Open AccessArticle

Edgewise Compression and Three-Point Bending Analyses of Repaired Composite Sandwich Panels

Ricardo J. B. Rocha

Marcelo F. S. F. de Moura

and

Raul D. F. Moreira

Materials 2023, 16(12), 4249; https://doi.org/10.3390/ma16124249 - 08 Jun 2023

Viewed by 549

Abstract

In this work, the fracture behaviour of repaired honeycomb/carbon–epoxy sandwich panels under edgewise compression and three-point bending loading was analysed. Assuming the occurrence of damage resulting from a complete perforation leading to an open hole, the followed repair strategy consists of plug filling the core hole and considering two scarf patches with an angle of 10° in order to repair the damaged skins. Experimental tests were performed on undamaged and repaired situations in order to address the alteration in the failure modes and assess the repair efficiency. It was observed that repair recovers a large part of the mechanical properties of the corresponding undamaged case. Additionally, a three-dimensional finite element analysis incorporating a mixed-mode I + II + III cohesive zone model was performed for the repaired cases. Cohesive elements were considered in the several critical regions prone to damage development. The failure modes and the resultant load–displacement curves obtained numerically were compared with the experimental ones. It was concluded that the numerical model is suitable for estimating the fracture behaviour of sandwich panel repairs. Full article

(This article belongs to the Special Issue Damage Analysis for Composite Materials: Methods, Testing and Evaluation)

► Show Figures

Figure 1

Open AccessEditor’s ChoiceArticle

Damage Propagation by Cyclic Loading in Drilled Carbon/Epoxy Plates

and

Susana C. F. Fernandes

Materials 2023, 16(7), 2688; https://doi.org/10.3390/ma16072688 - 28 Mar 2023

Cited by 2 | Viewed by 661

Abstract

Fiber reinforced composites are widely used in the production of parts for load bearing structures. It is generally recognized that composites can be affected both by monotonic and cyclic loading. For assembly purposes, drilling is needed, but holes can act as stress concentration notches, leading to damage propagation and failure. In this work, a batch of carbon/epoxy plates is drilled by different drill geometries, while thrust force is monitored and the hole’s surrounding region is inspected. Based on radiographic images, the area and other features of the damaged region are computed for damage assessment. Finally, the specimens are subjected to Bearing Fatigue tests. Cyclic loading causes ovality of the holes and the loss of nearly 10% of the bearing net strength. These results can help to establish an association between the damaged region and the material’s fatigue resistance, as larger damage extension and deformation by cyclic stress contribute to the loss of load carrying capacity of parts. Full article

(This article belongs to the Special Issue Damage Analysis for Composite Materials: Methods, Testing and Evaluation)

► Show Figures

Figure 1

Open AccessArticle

Predicting Failure of Additively Manufactured Specimens with Holes

Gina Eileen Chiara Schmeier

Clara Tröger

Young W. Kwon

and

Delf Sachau

Materials 2023, 16(6), 2293; https://doi.org/10.3390/ma16062293 - 13 Mar 2023

Viewed by 646

Abstract

Experimental and computational studies were conducted to predict failure loads of specimens containing different-sized holes made using the additive manufacturing (AM) technique. Two different types of test specimens were prepared. Flat specimens, manufactured from polylactic acid (PLA), were subjected to uniaxial loading. Tubular specimens, made of polycarbonate (PC), were subjected to combined loading that was applied using uniaxial testing equipment. Test specimens were uniquely designed and printed to apply the combined bending and torsional loads to tubular specimens. A newly developed failure theory was applied to predict the loads that would result in the fracture of these test specimens. This theory is composed of two conditions related to stress and the stress gradient to be simultaneously satisfied to predict failure. The failure loads predicted using the new failure criteria were compared closely with the experimental data for all test specimens. In addition, a semi-empirical equation was developed to predict the critical failure surface energy for different printing angles. The critical failure surface energy is a material property and is used for the stress gradient condition. Using the semi-empirically determined values for the failure criterion provided close agreement with experimental results. Full article

(This article belongs to the Special Issue Damage Analysis for Composite Materials: Methods, Testing and Evaluation)

► Show Figures

Figure 1

Open AccessArticle

Interfacial Shear Strength of Single-Walled Carbon Nanotubes-Cement Composites from Molecular Dynamics and Finite Element Studies

and

Rosario G. Merodio-Perea

Materials 2023, 16(5), 1992; https://doi.org/10.3390/ma16051992 - 28 Feb 2023

Viewed by 740

Abstract

Carbon nanotubes (CNTs) are nanometer-sized structures that can be used to reinforce cement matrices. The extent to which the mechanical properties are improved depends on the interfacial characteristics of the resulting materials, that is, on the interactions established between the CNTs and the cement. The experimental characterization of these interfaces is still impeded by technical limitations. The use of simulation methods has a great potential to give information about systems lacking experimental information. In this work, molecular dynamics (MD) and molecular mechanics (MM) were used in conjunction with finite element simulations to study the interfacial shear strength (ISS) of a structure formed by a pristine single-walled CNT (SWCNT) inserted in a tobermorite crystal. The results show that, for a constant SWCNT length, ISS values increase when the SWCNT radius increases, while for a constant SWCNT radius, shorter lengths enhance ISS values. Full article

(This article belongs to the Special Issue Damage Analysis for Composite Materials: Methods, Testing and Evaluation)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Special Issue "Damage Analysis for Composite Materials: Methods, Testing and Evaluation"

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Published Papers (7 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI