Showing papers on "Composite laminates published in 2022"
TL;DR: A review of numerical methodologies for ultrasound and guided wave simulation in fiber reinforced composite laminates summarizing the relevant works, different methods, and their respective applications can be found in this article .
19 citations
TL;DR: In this paper , both experimental and numerical analyses are performed covering a large design-space of laminates for all aspects from on-set of damage and barely visible impact damage up to clearly visible impact damages and full penetration of the laminated composite coupons, and an extensive validation test program of several configurations and impact energies has been performed, thus demonstrating that the simulations are capable of accurately predicting the damage and failure mechanisms under low-velocity impact loading.
19 citations
TL;DR: In this paper , three different types of composite laminates comprised of flax fibres only, and two hybrid flaxglass configurations were fabricated, with alternating flax/glass reinforced layers.
17 citations
TL;DR: In this article , the authors explored the failure and surface characteristics of glass fiber reinforced polymers (GFRP) and applied stepwise loading to understand the multi-static loading effect on the laminates before final failure.
Abstract: The present study explores the failure and surface characteristics of Glass Fiber-Reinforced Polymers (GFRP). Stepwise loading was applied in this study to understand the multi-static loading effect on the laminates before final failure. The loading was set three times to reach 10 kN with loading–unloading movement before final load until failure. The results showed that the angle of the GFRP UD laminates’ position significantly impacts the system’s failure. The results were analyzed using theoretical calculation experiment analysis, and then the failure sample was identified using ASTM D3039 standard failure. The laminates with 0° layer on edge ([0/90]S laminates) underwent preliminary failure before final failure. The mechanism of stepwise loading can be used to detect the effect of preliminary failure on the laminates. The [0/90]S laminates are subjected to stress concentration on the edge due to fiber alignment and discontinued fibers in the 0-degree direction. This fiber then fails due to debonding between the fiber and the matrix. The laminates’ strength showed that [90/0]S specimens have an average higher strength with 334.45 MPa than the [0/90]S laminates with 227.8 MPa. For surface roughness, the value of Ra increases more than six times in the 0° direction and three times in the 90° direction. Moreover, shore D hardness showed that the hardness was decreased from 85.6 SD then decreased to 70.4 SD for [0/90]S and 65.9 SD for [90/0]S. The matrix debonding, layer delamination and fiber breakage were reported as the failure mode behavior of the laminates.
17 citations
TL;DR: In this paper , a novel delamination growth criterion is proposed for mixed-mode I/II delamination predictions considering the significant R-curve effects in composite laminates.
16 citations
TL;DR: In this article , a finite element model is established to study the complex damage and failure mechanisms by employing ABAQUS/Explicit. And the relationship between impact energy and impact performance such as peak force, maximum displacement, and absorbed energy are analyzed.
15 citations
TL;DR: In this paper , the displacement field of a 2D wing-shaped double-double composite model under three loading conditions (tension, shear and bending) is predicted using a data-driven strategy.
15 citations
TL;DR: In this paper , the authors investigated the mode II fatigue delamination growth (FDG) behavior of multidirectional laminates under three kinds of stress ratio by using end-notch flexure set-up.
15 citations
TL;DR: In this article, the dynamic response of woven carbon fiber reinforced thick composite laminates under low-velocity impact was investigated by using the ABAQUS/Explicit finite element model.
15 citations
TL;DR: In this paper , a hand-laid-up composite laminates with novolac resin and sisal/coir/E-glass fiber reinforcement (60:40) were fabricated using the hand lay-up method.
Abstract: Natural fiber- reinforced composites are currently being researched for their selection and use in the industries spanning aerospace, automotive, ground transportation, and several other high- performance-critical end products. Two of the key reasons in favor for the selection and use of natural fibers are, their biodegradability coupled with an overall ease of availability that makes the production of engineered composites not only cost effective but also economically viable. However, the selection and use of natural fibers/matrix is curtailed primarily because of three competing drawbacks, namely (i) high moisture absorption, (ii) inferior mechanical properties, and (iii) poor interfacial bonding strength between fiber and matrix, when compared one-on-one with the synthetic fibers/matrix. Due to these reasons, natural fibers are often used in combination with synthetic fibers for engineering composites, so as to achieve a material that offers the possibility of improved performance at the desired level. In this research study, composite laminates with novolac resin and sisal/coir/E-glass fiber reinforcement (60:40) were fabricated using the hand lay-up method. The fabricated composite laminates were characterized for macromechanical properties, namely, tensile strength and water absorption test was conducted to explore the moisture absorption characteristics of composite laminates. Test results revealed the composite laminates with natural fibers/resins to possess many attributes in favor of their selection and use in structural components.
14 citations
TL;DR: Based on the Castigliano theorem and the point friction theory, a semi-analytical method for determining mode-II fracture toughness and bridging law is established in this paper , which is integrated into a cohesive zone model for delamination growth modelling.
TL;DR: In this article , a novel shear-dependant, smart layer consisting of a polyborosiloxane (PBS)-based Shear Stiffening Gel (SSG), encapsulated in crosslinked vinyl-terminated polydimethylsiloxane, acting as a protective layer on the surface of Carbon Fibre Reinforced Polymer (CFRP) laminates reducing impact damage.
Abstract: This work presents a novel shear-dependant, smart layer consisting of a polyborosiloxane (PBS)-based Shear Stiffening Gel (SSG), encapsulated in crosslinked vinyl-terminated polydimethylsiloxane (VPDMS), acting as a protective layer on the surface of Carbon Fibre Reinforced Polymer (CFRP) laminates reducing impact damage. The frequency-dependant reversible network structure of the PBS smart layer acts as a dynamic responding energy absorption medium (DrEAM), able to autonomously stiffen in response to an external stimulus. Low Velocity Impact (LVI) tests were employed to assess the energy absorption characteristics of the smart layers which were compared to a VPDMS film and an uncoated CFRP laminate. Results indicated that DrEAM smart layers are able to modify the way the energy is distributed due to the dynamic phase transition of the embedded SSG. These were further confirmed by Non-Destructive Testing analyses, where DrEAM coatings allowed for an average reduction of 65% of the extent of the internal damage in comparison with the CFRPs and outperformed VPDMS by showing a further reduction of 33% at low energy (10 J) and by more than 50% for higher energy (20 J), providing a complete low-cost solution for the protection of CFRP laminates subjected to out-of-plane impacts such as in aerospace or railways components.
TL;DR: In this article , a moment-independent stochastic sensitivity analysis of laminated composite plates is proposed for establishing a unified measure in the case of multi-objective performances, based on weighted relative importance of different performance parameters by introducing the notion of engineering judgment.
TL;DR: In this article, the physics of spatial material randomness in CFRP composites is incorporated in a concurrent multiscale modeling framework and a sampling based non-intrusive approach is adopted to demonstrate natural variability in the material.
TL;DR: In this paper , the effect of thickness on the dynamic mechanical response and damage mechanism of composite laminates under single and repeated low-velocity impact is investigated numerically by considering the thickness effect.
TL;DR: In this paper , the effects of ply thickness and the 0°layer ratio on the strength and damage behavior of thin-ply composite laminates were examined using X-ray radiography.
TL;DR: In this paper , a method coupling finite element analysis (FEA) and machine learning is established to analyze three examples of composite laminates, such as failure factor of Puck theory under random stress state, failure factor and critical buckling eigenvalues of open-hole laminate.
TL;DR: Wang et al. as mentioned in this paper proposed a modified minimum variance method, where waveform information was integrated into algorithm imaging procedure to improve the performance of image reconstruction and localization. But, this method is not suitable for low-resolution images.
Abstract: Lamb wave minimum variance imaging is a promising method for visual damage identification and localization with a sparse transducer array. Imaging performance of minimum variance is highly dependent on the design accuracy of look-direction to describe amplitude relationship of array reflection signals. Look-direction is the combination of a directivity reflection pattern and an attenuation with propagation distance. However, reflection pattern is closely related to damage parameters (e.g. type, orientation and size) and these parameters are usually unknown beforehand. Therefore, accurate design of look-direction is difficult or even impossible, and design error can significantly degrade imaging performance. To overcome this limitation, a modified minimum variance method is proposed in this study. Besides amplitude information, waveform information is integrated into algorithm imaging procedure. Correlation coefficient between local signal and excitation waveform is calculated to generate the distribution of weights for diagonal loading. Diagonal loading weight is an adjustable coefficient in minimum variance algorithm to control the tolerance for look-direction error. With larger weights for potential damage locations, tolerance for inaccuracy in look-direction is increased, and imaging performance is accordingly improved. Experiments on both aluminum plates and composite laminates are carried out to demonstrate the performance improvement of modified method.
TL;DR: In this paper , the authors combine finite element methods (FEM) and experimental tests to investigate the defect detection capabilities of shearography for inspecting thick glass fiber-reinforced polymer laminates.
TL;DR: Wang et al. as mentioned in this paper proposed a modified minimum variance method, where waveform information was integrated into algorithm imaging procedure to improve the performance of the LW imaging with a sparse transducer array.
Abstract: Lamb wave minimum variance imaging is a promising method for visual damage identification and localization with a sparse transducer array. Imaging performance of minimum variance is highly dependent on the design accuracy of look-direction to describe amplitude relationship of array reflection signals. Look-direction is the combination of a directivity reflection pattern and an attenuation with propagation distance. However, reflection pattern is closely related to damage parameters (e.g. type, orientation and size) and these parameters are usually unknown beforehand. Therefore, accurate design of look-direction is difficult or even impossible, and design error can significantly degrade imaging performance. To overcome this limitation, a modified minimum variance method is proposed in this study. Besides amplitude information, waveform information is integrated into algorithm imaging procedure. Correlation coefficient between local signal and excitation waveform is calculated to generate the distribution of weights for diagonal loading. Diagonal loading weight is an adjustable coefficient in minimum variance algorithm to control the tolerance for look-direction error. With larger weights for potential damage locations, tolerance for inaccuracy in look-direction is increased, and imaging performance is accordingly improved. Experiments on both aluminum plates and composite laminates are carried out to demonstrate the performance improvement of modified method.
TL;DR: In this article , the authors proposed an approach to develop higher-order finite elements by taking progressive damage into account in the formulation, which is implemented as a UEL (User Element subroutine) written in FORTRAN and linked to Abaqus.
Abstract: This works proposes a novel approach to develop higher-order finite elements by taking progressive damage into account in the formulation. The approach is based on Carrera’s unified formulation (CUF) while the damage model is based on continuum damage mechanics (CDM) principles, which is implemented as a UEL (User Element subroutine) written in FORTRAN and linked to Abaqus. The approach is assessed by simulating a plate under distributed and sinusoidal loads. Besides, a progressive damage analysis of a composite coupon under three-point bending is simulated, and the numerical predictions are compared against experimental results, showing good correlation. The main findings show that the implemented UEL is accurate and fast enough to predict progressive failure events and the in-plane damage mechanisms for composite laminates under bending loadings. • A damage model with finite elements based on CUF is developed. • The integrated framework is implements as a single UEL subroutine. • All steps to develop the subroutine are explained in detail. • Results are validated against experimental findings.
TL;DR: In this paper , an eight-noded isoparametric element using first-order shear deformation theory based finite element formulation is adopted for discretizing the domain.
TL;DR: In this article , a micro-structured Z-pin reinforced laminates using circumferentially notches as a defined z-pin surface microstructuring was investigated.
TL;DR: In this article , a series of three-point bending tests were conducted to study the bending behavior of different CARALLs under fiber reinforced plastic composite/metal alternative stacking sequence, and the bending properties and damage behavior of two fiber orientations (unidirectional and cross-ply) in 3/2-FMLs were investigated by Linde failure criterion, which was in agreement with the experimental load-deflection curves and microstructural analysis.
TL;DR: In this article, the conditions under which complex-valued dispersion equations are either real- or purely imaginary-valued equations (termed as dichotomy property) are derived for both single and multi-layered composite plates.
TL;DR: In this article , a crack simulation coupling the phase field approach and the cohesive zone model is used for identifying crack migration through material layers. And the crack paths and the related force displacement curves of 2D multilayered material models of complex laminates are predicted and compared.
Abstract: Abstract Delamination and cracking of matrix/fiber is a common failure phenomena reported in fiber reinforced composite materials. As complex stress states develop in laminated structures, they are prone to develop fracture phenomena. Therefore, designs with large damage tolerance are currently implemented in most of the industrial sectors. This can be achieved by designing such materials with superior fracture resistance, which requires a comprehensive understanding of failure mechanisms. Cohesive Zone Models (CZM) are a popular technique to study debonding and decohesion in composite structures. Furthermore, due to the accurate simulation of complex crack paths including crack branching, the Phase Field (PF) approach has gained notable relevance in fracture studies, including the interplay between debonding and crack propagation in the matrix. In order to get a further insight into these intricate scenarios, involving bridging mechanisms in intralayer and interlayer, crack simulation coupling the phase field approach and the cohesive zone model is herein exploited for identifying crack migration through material layers. The crack paths and the related force–displacement curves of 2D multilayered material models of complex laminates are predicted and compared.
TL;DR: In this article , the authors study the multi-impact behavior of composite laminates as well as verify if a linear damage accumulation law can predict the multinomial lifetime of composite materials.
TL;DR: In this paper , a new technique of creating a delamination defect is presented to produce a thin air gap for measuring realistic ultrasonic responses, and a support vector machine (SVM) classifier has been used to improve delamination detection accuracy.
TL;DR: In this paper , a unified fatigue damage model for composite materials is proposed, which is capable of characterizing fatigue damage development caused by strength degradation and stiffness degradation, respectively, and a pair of residual strength and residual stiffness models are presented to estimate the performance degradation of composite materials.
TL;DR: In this paper , the authors employed the acoustic emission (AE) technique to monitor the performance degradation process and to estimate the residual loadbearing abilities of glass fiber/epoxy composite laminates with the damage evolution of various failure modes.