Composite Failure Research Articles

Experimental and numerical investigation on effects of gas adsorption pressures on damage behaviors, failure characteristics, and energy evolution of coals

Coal and gas outbursts are anthropogenic hazards that can be divided into four stages: preparation, occurrence, development, and termination. Studying the influence of gas on coal damage and energy changes during the formation of outbursts is highly important for investigating the entire hazard. In this paper, laboratory experiments were performed on samples. The energy changes and failure mechanism of coal under different gas pressures were revealed, and a seepage model was established based on compressibility and adsorption to investigate gas-induced coal damage. The results demonstrated that gas pressure caused initial damage within the coal, resulting in nonlinear deformation and strength deterioration of the coal. Gas-induced damage affected the energy evolution mechanism of coal under loading, as pressure caused the premature release of energy at the tips of internal microcracks and reduced the ability to accumulate energy. These changes increased the proportion of dissipative energy under unstable conditions. The combined acoustic emission (AE) parameters—rising angle (RA) and average frequency (AF)—were used to study the fracture mode of gas-containing coal. As the gas pressure increased from 0 to 4 MPa, the RA–AF distribution pattern changed from tensile failure to tensile–shear composite failure, with the proportion of shear cracks increasing from 0.30% to 25.44%. As the complexity of the crack network increased, the randomness of crack propagation increased, and the fracture surface roughness parameters, arithmetic mean height Sa, root mean square height Sq, and maximum height Sz increased by 90.33%, 94.02%, and 81.70%, respectively. These findings could contribute to a comprehensive understanding of the underlying mechanism of coal and gas outbursts and guide for predicting and preventing these hazards.

Investigation of Thermomechanical Analysis of Carbon/Epoxy Composite for Spacecraft Structure Material

When building spacecraft structures, it is crucial to use lightweight and high-strength composite materials with the necessary characteristics. Aerospace applications benefit significantly from the exceptional properties of carbon/epoxy composite materials. As part of a study on composite materials, this work focuses on exploring the thermo-mechanical properties of carbon fiber. The matrix used in this research is LY-5052 epoxy, applied through a vacuum infusion technique. To achieve optimal composite properties, various tests are conducted to evaluate its thermo-mechanical behavior. These tests may include measuring Thermal Conductivity and performing thermogravimetric analysis (TGA). Most importantly, the composite is subjected to tensile testing at room temperature to 200 °C. This is done because most tensile tests on carbon/LY5052 composites are carried out at room temperature. The results obtained from the measurement of the thermal conductivity of the carbon/LY5052 composite were 0.419 W/mK; from the Thermogravimetric Analysis (TGA), the carbon/LY5052 composite began to decompose at a temperature of 365.63 °C and the tensile test was carried out simultaneously with variations in temperature from room temperature, 50 °C, 100 °C, 150 °C and 200 °C have tensile strengths of 553, 507, 340, 266, and 242 MPa, respectively. This trend confirms that strength decreases with higher temperature loads. Several image observations are also presented in this report to understand composite materials' failure behavior at these various temperatures.

Inhaled nitric oxide and postoperative outcomes in cardiac surgery with cardiopulmonary bypass: A systematic review and meta-analysis

Cardiac surgeries under cardiopulmonary bypass (CPB) are complex procedures with high incidence of complications, morbidity and mortality. The inhaled nitric oxide (iNO) has been frequently used as an important composite of perioperative management during cardiac surgery under CPB. We conducted a meta-analysis of published randomized clinical trials (RCTs) to assess the effects of iNO on reducing postoperative complications, including the duration of postoperative mechanical ventilation, length of intensive care unit (ICU) stay, length of hospital stay, mortality, hemodynamic improvement (the composite right ventricular failure, low cardiac output syndrome, pulmonary arterial pressure, and vasoactive inotropic score) and myocardial injury biomarker (postoperative troponin I levels). Subgroup analyses were performed to assess the effect of modification and interaction. These included iNO dosage, the timing and duration of iNO therapy, different populations (children and adults), and comparators (other vasodilators and placebo or standard care). A comprehensive search for iNO and cardiac surgery was performed on online databases. Twenty-seven studies were included after removing the duplicates and irrelevant articles. The results suggested that iNO could reduce the duration of mechanical ventilation, but had no significance in the ICU stay, hospital stay, and mortality. This may be attributed to the small sample size of the most included studies and heterogeneity in timing, dosage and duration of iNO administration. Well-designed, large-scale, multicenter clinical trials are needed to further explore the effect of iNO in improving postoperative prognosis in cardiovascular surgical patients.

Performance analysis of fiber-reinforced polypropylene composite laminates under quasi-static and super-sonic shock loading conditions for impact application

In the present research, glass and basalt fiber-reinforced polypropylene composites’ behaviour in quasi-static and dynamic conditions is studied. Composites were fabricated by vacuum assisted Compression molding method. Composites failure under quasi-static tension and compressive conditions was studied along with its failure behaviour under low-velocity impact and super-sonic shock loading under dynamic conditions. The study results showed that basalt fiber-reinforced polypropylene (Basalt/PP) composite’s tensile and compressive strength is higher than glass fiber-reinforced polypropylene (Glass/PP). The Basalt/PP showed no penetration against low velocity impact (LVI) with negligible deformations till 50 J. However, the Glass/PP perforated at 50 J with various failure patterns occurring at back side. The fiber-matrix interface adhesion plays an important role in super-sonic shock loading by absorbing shock wave energy due to ductile nature of polypropylene and the two composites absorbed energy via matrix and fibers failure, no brittle failure of laminates occurred under shock loading.

Efficacy of Sacubitril-Valsartan on Survival and Cardiac Remodeling in Hypotensive Heart Failure With Reduced Ejection Fraction: A Multicenter Study

ObjectiveTo investigate whether hypotensive patients diagnosed with heart failure and reduced ejection fraction (HFrEF) might benefit from angiotensin receptor–neprilysin inhibitors (ARNis) in real-world practice because patients with baseline systolic blood pressure (SBP) of less than 100 mm Hg have been excluded from landmark trials. Patients and MethodsIn this multicenter study conducted between January 1, 2013, and December 31, 2021, a total of 7562 symptomatic patients with HFrEF were enrolled and grouped by SBP (hypotension was defined as an SBP of less than 100 mm Hg) and ARNi use as follows: group 1, hypotensive/non-ARNi users (n=484); group 2, hypotensive/ARNi users (n=308); group 3, nonhypotensive/non-ARNi users (n=4560); and group 4, nonhypotensive/ARNi users (n=2210). Inverse probability of treatment weighting was used to balance baseline characteristics for survival analysis. ResultsDiverse baseline characteristics and lower rates of medication use were found among non-ARNi users compared with ARNi users. Hypotensive/ARNi users had lower ARNi initiation doses than nonhypotensive/ARNi users. We observed significantly lower mortality, composite heart failure hospitalization, and CV death for hypotensive/ARNi and the other 2 nonhypotensive groups (groups 3 and 4) during a median follow-up of 3.43 years (all P<.05), with a similar effect on reverse remodeling for the hypotensive/ARNi group compared with the hypotensive/non-ARNi group. The event-free survival benefits of ARNi vs renin-angiotensin system inhibitors were consistent with the lower boundary of SBP for clinical benefits found until 88 mm Hg (spline curves) after inverse probability of treatment weighting. ConclusionPatients with HFrEF and hypotension may still benefit from ARNi treatment. Patients with hypotensive HFrEF should not be routinely excluded from ARNi use in a real-world setting.

Mobility and energy efficient services composition algorithm with QoS guarantee for large scale Cyber–Physical–Social Systems

Due to the mobile and random nature of services in cyber–physical–social systems (CPSSs), developing service composition approaches that ensure high availability, minimal energy consumption, and high quality of service (QoS) remains a complex challenge. Over the last two decades, several service composition approaches have been proposed in the literature to deal with this challenge. Nevertheless, the existing approaches have certain limitations, particularly in situations where services may move from one location to another, become unavailable due to intensive battery usage, encounter failures, or undergo a decline in quality. These limitations often arise because these approaches do not simultaneously integrate mobility, energy, and QoS constraints while defining the user’s movement in a random manner. In this paper, the learning-based swarm optimization-aware service composition algorithm (LS-SCA) is proposed to overcome the aforementioned shortcoming. This approach surpasses existing ones by accounting simultaneously for the user’s mobility, energy, and QoS criteria during the service composition process. First, the Small World in Motion (SWIM) mobility model is employed in this study to determine the user’s mobility traces, avoiding the random generation of users’ traces. Second, an energy consumption model is proposed to increase the energy efficiency by avoiding the overuse of the devices’ batteries that can reduce the availability of services and lead to the composition failure. Third, the two-phase learning-based swarm optimizer (TPLSO) method is used in the composition process to find the sub-optimal composition that satisfies the global QoS constraints with the highest utility in terms of mobility, energy, and QoS. Unlike the most existing metaheuristic-based service composition approaches where the overall composition population is improved over a given number of iterations, the TPLSO method is exploited in this paper to improve only a subset of compositions, which reduces the composition time and increases the QoS utility of the composition. The simulation scenarios using two real datasets demonstrate that the LS-SCA approach outperforms six baselines in terms of energy consumption, QoS utility, and availability of composition. This notable performance makes the proposed approach more suitable for real-world applications where energy efficiency, QoS, and availability are crucial factors to consider.

Effect of early damage on the mechanical properties, localized deformation and damage failure of cemented tailings backfill

To investigate the effect of early damage on the mechanical properties of cemented tailings backfill (CTB) in the later stage, different degrees of stress damage were applied to CTB at different curing age. Unconfined compressive strength (UCS) and ultrasonic testing were conducted on CTB. The acoustic emission (AE) and digital speckle correlation methods were used to analyze the AE response characteristics and localized deformation patterns of CTB. The results show that when the damage age (DA) is short and the damage degree (DD) is low, a smaller compressive stress can improve the internal density of CTB and enhance its UCS and wave velocity. A high compressive stress has a deteriorating effect on the UCS and wave velocity of CTB. When DA is 14 d, the amount of hydration products generated inside the CTB has decreased, and it is not enough to fill the cracks caused by stress damage, reducing the UCS and wave velocity of the CTB. An increase in DD can enhance the elastic modulus of CTB at various curing age. As DD increases, the failure mode of CTB transitions from shear failure to splitting tensile failure and then to composite failure via shear and splitting tensile failure. The AE counts and energy peak values of CTB increase continuously with increasing DD. When the DD is 40%, 60%, or 80%, there is a significant sudden increase in the AE count and energy near the peak stress point, which can be used as a precursor to CTB instability and failure.

Mechanical behavior of bio‐inspired composites made of co‐continuous geopolymer and 3D‐printed polymer

AbstractGeopolymers (GPs) are emerging, low‐density ceramic materials that are simple to manufacture, with high elastic modulus and strength, albeit with low toughness. Fiber reinforcements have been used to achieve varied ductile behaviors, but little is known about the GP addition to polymeric frame structures. Thus, drawing inspiration from the nanostructure of bones, this paper investigated an interpenetrating, co‐continuous composite consisting of a GP as the stiff but brittle phase, and a 3D‐printed polymer (PA12 White) as the soft and deformable phase. The composite mechanical properties and failure modes were studied experimentally using uniaxial compression and four‐point bending tests. The co‐continuous network constrained brittle cracking within the GP and reduced strain localization in the polymer. The results showed that the composite had higher strength (56.11 ± 2.12 MPa) and elastic modulus (6.08 ± 1.37 GPa) than the 3D‐printed polymer and had higher toughness (5.98 ± 0.24 MJ/mm3) than the GP for the specific geometries examined. The shape effect study demonstrated that cubic structures had higher elastic modulus and strength but at the expense of lower toughness when compared to rectangular prism structures. The study of scale effects indicated that increasing the number of periodic unit cells while maintaining consistent bulk dimensions led to augmented strength and toughness, albeit without statistically significant alterations in elastic modulus. Thus, this paper presents an experimental realization of a novel, bio‐inspired, interpenetrating, GP–polymer composite design, offering improved strength and toughness. It also provides valuable insights into the shape and size effects on the mechanical properties of this new composite.

Study on mechanical properties and failure mechanism of hard rock with stiff discontinuities based on 3D printing

To examine the influence of stiff discontinuities with different angles and roughness on the stability of deep hard rock engineering, RLSD is created through the integration of 3D scanning, digital modeling, and 3D printing. The specimen's composition truly reflects the mineral components of the original rock. The impact of angle and roughness on the strength, deformation, and failure characteristics of RLSD is explored by uniaxial tests. The failure process and mechanism of specimens under the influence of stiff discontinuity feature are investigated through the integration of DIC, AE, and SEM test. The study results demonstrate that achieving highly similar specimen of hard rock containing stiff discontinuities with different angles and roughness is attainable by utilizing rock-like materials based on original rock mineral components and employing a combination of 3D scanning and 3D printing techniques. The peak strength, peak strain and elastic modulus of RLSD increase with the increase of JRC, and there is a V-shaped trend of“decrease first and then increase” with the increase of angle. The failure mode of RLSD shows the change rule of tension failure - tension-shear composite failure - shear failure - tension-shear composite failure - tension failure with the increase of angle. At angles of 60° and 75°, a sudden increase in hit and energy of AE feature is observed in RLSD, resulting in brittle failure. The cumulative energy exhibits a positive correlation with JRC. Based on the test results, an empirical estimation formula is established for the uniaxial compressive strength of RLSD, considering the influence of angle and JRC. The research results can provide reference for estimating the strength of surrounding rock in deep underground engineering as well as disaster prevention and control.

Experimental Research on Impact Resistance Test of Polycrystalline Diamond Compact Based on Digital Image Correlation Method

In this study, the impact resistance of Polycrystalline Diamond Compact (PDC) was studied with DIT drop weight tester and high speed camera. The surface of PDC was analyzed by Digital Image Correlation (DIC). The reason of impact failure of PDC was obtained by using the surface strain field of PDC. The results show that local delamination occurs near the impact point of the polycrystalline layer. The brittle fracture occurs at the maximum tensile strain of the impact resistant composite sheet. The quantitative relationship between the surface strain and the image obtained by DIC can effectively reflect the whole process of PDC composite failure, and can reasonably explain the failure process of PDC composite, and provide scientific research methods for engineering applications.

Evaluation of Microvoid and Microleakage Potential of Bulk-Fill Resin Composites in MOD Restorations

Background: Polymerization shrinkage and microvoid formation has been a significant problem giving way to resin composite failure. The aim of this study was to evaluate the microvoid potential and microleakage of two bulk-fill and a microhybrid resin composite applied with different adhesive materials. Materials and Methods: MOD cavities were prepared in 60 endodontically treated maxillary premolars. The teeth were divided into six different groups (n = 10) according to adhesive systems (Gluma (Kulzer), OptiBond FL (Kerr) and resin composite materials EverX Posterior (GC) and Filtek One Bulk Fill (3M ESPE). An aging procedure with 5000 cycles of thermal cycling was applied. All teeth were individually scanned with micro-computed tomography. A Shapiro–Wilk test, two-way MANOVA, and Bonferroni analysis were used for statistical tests. Results: Self-etch groups showed more microleakage than total-etch groups. Minimum microleakage was observed in Filtek One Bulk Fill groups, whereas G-aenial Posterior groups showed maximum microleakage. Conclusions: Filtek One Bulk Fill (3M ESPE) resin composite was found to be more effective in reducing microvoid formation in MOD cavities when applied with total-etch adhesive systems. However, EverX Posterior (GC) and G-aenial Posterior (GC) showed less microvoid formation with self-etch adhesive systems.

Fractographic analysis of fiber‐reinforced polymer laminate composites for marine applications: A comprehensive review

AbstractIn the past decade, polymer‐based glass fiber‐reinforced laminate composites have gained significant popularity in various mass transit applications, including marine, aircraft, and automotive industries. However, it is crucial to consider the degradation and potential failure of these materials, especially in mass transit networks. To address this concern, fractographic analysis has emerged as a valuable approach for investigating fracture surfaces, extracting vital information, and facilitating the development of new materials. Furthermore, it sheds light on the underlying physical mechanisms that contribute to composite failure. This paper primarily focuses on examining flaws, failure modes, and performing fractography analysis on fiber‐reinforced polymer (FRP) laminate composites subjected to various loading conditions such as tension, compression, flexure, impact, shear, and fracture. Fractography, as an indispensable method, plays a pivotal role in the comprehensive development of composite structures and has become a reliable tool for composite engineers. The outcomes of this study are expected to serve as a foundation for identifying areas that require further investigation in terms of fracture analysis and failure modes specific to FRP composite materials, particularly those used in marine applications.Highlights Introduction to FRP laminate composites in marine structures. Concise analysis of failure modes in FRP laminate composites. SEM fractography review of FRP laminate composites under varied loading conditions. Comprehensive study on tensile, flexural, impact, compression, shear, and fracture toughness failure modes. Summarization of identified defects in FRP composites.

Effect of bio nanofiller in influencing the carbon and E-glass fabric reinforced composites

The exceptional mechanical properties, dimensional stability and low cost of production of textile composites have made them quite popular in recent years. In the present analysis, plain woven inter, intra and hybrid carbon and E-glass fibre reinforced composites incorporated with or without nano-coconut shell ash (CSA) as filler were manufactured by hand lay-up method. The mechanical and thermal properties were determined for the manufactured composites. Simultaneously, the fractographic study was conducted by scanning electron microscopy to predict the different kind of failures in composites. The mechanical properties of the composites were found to be significantly better when 2 wt.% of CSA was substituted in it. The inter-hybrid composite containing 2 wt.% nanofiller demonstrated the highest tensile strength of 245.96 MPa, flexural strength of 496.03 MPa and maximum degradation temperature with weight change of 81.08%. A combination of intra- and inter-hybrid woven composite revealed the highest impact resistance of 3.3 J. The pseudo-ductile performance of intra-hybrid composites is also distinctly observed, showing moderate tensile stress of 299.376 MPa and maximum elongation of 5.137 mm. The current scientific effort makes it clear that the greatest tensile strength was obtained by positioning carbon fibres inside and the glass fibres outside. The surface proximity and diffusion of nanofillers in the composites further enhanced their tensile properties. Shear dispersion also led to maximum energy absorption without the need for nanofiller in case of combination of intra- and inter-woven fibre composites.

Construction of irregular and high-density microtexture on ultra-thin 304 austenitic stainless steel strip via laser surface treatment to improve steel/epoxy resin adhesive bonding properties

Ultra-thin steel strip can be used in composite materials to create high-performance and low-deadweight components for the aerospace industry. The present study used a laser to create surface microtextures on 304 austenitic ultra-thin stainless steel (SS) strips to improve their adhesion to epoxy resin. Modification was conducted at various laser power levels, resulting in ring-like textures of various qualities. The strips were bonded to epoxy resin at single-lap joints, which were then strength-tested. The bonding mechanisms were investigated via analyses of microstructure, surface chemical composition and interfacial failure modes. The laser power level affected the density and distinctiveness of the ring-like structures. The optimal level of 40 W produced a bond with a shear strength of 14.43 MPa. Bonding is enhanced by the interlocking effect of the texture, improved wettability between the steel and epoxy resin, and –C–O=C polar bonds. Lower and higher power levels provided weaker textures. In summary, irregular laser surface treatment can optimize the shear strength of SS–epoxy-resin joints, allowing the fabrication of stronger componentry.

Dalbavancin Sequential Therapy for Gram-Positive Bloodstream Infection: A Multicenter Observational Study.

Long-acting lipoglycopeptides such as dalbavancin may have utility in patients with Gram-positive bloodstream infections (BSI), particularly in those with barriers to discharge or who require prolonged parenteral antibiotic courses. A retrospective cohort study was performed to provide further multicenter real-world evidence on dalbavancin use as a sequential therapy for Gram-positive BSI. One hundred fifteen patients received dalbavancin with Gram-positive BSI, defined as any positive blood culture or diagnosed with infective endocarditis, from 13 centers geographically spread across the United States between July 2015 and July 2021. Patients had a mean (SD) age of 48.5 (17.5) years, the majority were male (54%), with many who injected drugs (40%). The most common infection sources (non-exclusive) were primary BSI (89%), skin and soft tissue infection (SSTI) (25%), infective endocarditis (19%), and bone and joint infection (17%). Staphylococcus aureus accounted for 72% of index cultures, coagulase-negative Staphylococcus accounted for 18%, and Streptococcus species in 16%. Dalbavancin started a median (Q1-Q3) of 10 (6-19) days after index culture collection. The most common regimen administered was dalbavancin 1500mg as one dose for 50% of cases. The primary outcome of composite clinical failure occurred at 12.2%, with 90-day mortality at 7.0% and 90-day BSI recurrence at 3.5%. Dalbavancin may serve as a useful tool in facilitating hospital discharge in patients with Gram-positive BSI. Randomized controlled trials are anticipated to validate dalbavancin as a surrogate to current treatment standards.

Influence of unidirectional composite failure envelope shape on predicting compressive failure of a laminate with a filled-hole

In recent decades, several computational models have emerged at the mesoscale for predicting the failure development and strength of composite materials. Nevertheless, the intricate failure mechanisms of composites pose a formidable challenge in developing models capable of consistently reproducing diverse sets of experimental data. Furthermore, the absence of standardised multiaxial tests has hindered consensus on failure envelopes and criteria for composites. In this work, an in-house constitutive model implemented in a finite element code is employed to predict the failure strength of several filled-hole compressive carbon/epoxy experimental tests, varying in stacking sequences, sizes, bolt preloads, and other parameters. The influence the selected failure criterion has on the predictions is analysed. The findings indicate a large impact of the failure envelope on both the failure compressive strength and developed failure mechanisms. Therefore, the correct adjustment of the failure criteria can be as relevant as defining accurately the material input parameters. These results emphasise the importance of accurately establishing failure envelopes, rather than overemphasising the development of complex models.

Composite structure failure analysis post Lithium-Ion battery fire

The use of composite materials has expanded significantly in a variety of sectors. In road transport,lithium-ion batteries (LIB) are the most commonly used.It is standard practice for batteriesto be housed within a metal enclosure, whichprotects and enables extinguishment in the event ofThermal Runaway (TR). Composite materials have been shown to contribute to lightweighting in many vehicle structures and their use inbattery enclosures has been growing in recent years - with the aim of reducing the weight of the battery assembly and positively impacting vehicle range.This work develops Finite Element (FE) models to assess thermal and mechanical damage and failure mechanisms during a TR event considering a section of a composite battery enclosure. Experimental data for a cylindrical 18650 lithium-ion battery fire is studied and used to define representative thermal loading. This validated loading profile is applied to a composite specimen and material temperature data is used to appraise damage. Finally, the predicted damage isused to predict and quantify the residual failure mechanism and strength of the specimen post battery fire. Results have shown the presence of damage from a single cell runaway can potentially reduce the strength of the specimen by 20% while multi-cell runaway can potentially reduce the strength by 56%. The predictive simulation capability herein could be used as a design tool for battery fire protection of composite enclosures, potentially reducing the need for corrective action, minimising the number of physical tests to support design and certification, as well as aiding in the interpretation of physical test results.

Shear Mechanical Properties of Bolt-Grout Interface under Different Bolt Surface Profiles

The shear behavior of the Bolt-Grout interface has a significant effect on the stability of a bolting system. In this paper, a series of shear tests were conducted on Bolt-Grout interfaces, and the effects of rib spacing, rib angles, and normal stress on the shear characteristics and failure modes of the Bolt-Grout interface were investigated. The results showed that the shear strength varied nonlinearly with an increase in rib spacing and angle, and also that it increased linearly with an increase in normal stress. With smaller rib spacings, the effect of rib spacing on peak shear strength was more apparent. The failure modes of the interface can be categorized as shear-slip failure, shear-break failure, and composite failure. The proportion of shear-slip failure and shear-break failure mainly depends on the rib spacing, rib face angle and normal stress.

Experimental and numerical investigation on Multiwalled carbon nanotubes (MWCNTs) dispersed CFRP laminate subjected to spherical and conical impacts

ABSTRACT As lightweight and load-bearing efficiency needs have grown, conventional metal has steadily given way to carbon fibre-reinforced polymer (CFRP) laminates. Also, CFRP laminates are more prone to localised damage due to impact loads like tool drop, runway debris and hail stone. This paper, investigated the penetration and perforation behaviour of CFRP laminate reinforced with 0.2 and 0.5 wt% MWCNTs. The projectile impact experiment was conducted using spherical and conical projectiles and the impact resistance was evaluated. The results revealed that 0.5 wt% MWCNTs embedded in CFRP laminate provided better impact resistance to both projectiles. The ballistic limit velocity was enhanced by 14.2% and 17.9% for spherical and conical projectiles, respectively, in the case of 0.5 wt% MWCNTs. Furthermore, numerical simulations were performed using an orthotropic model with Chang-Chang composite failure criteria. The results from numerical findings were consistent. It was concluded that MWCNTs reinforcement improves the projectile impact resistance and energy absorption.

Effect of thermoplastic particles on the mechanical performance and damage failure of notched fibre metal laminates

This study aims to explore the open-hole tension of fibre metal laminates containing thermoplastic particles experimentally and theoretically. In this regard, a vacuum bagging infusion process has been used to manufacture glass and glass metal laminates. Further, the tensile strength and damage failure modes were predicted using the Abaqus software, finite element analysis (FEA). This prediction was performed under a tensile test for notched composite laminates. The results of experimental tests indicated that the notch sensitivity is very important in terms of fracture and failures of composites. Furthermore, the findings show that the fibre metal laminates are less notch sensitive than glass composite laminates because of enhancing the composite ductility. In total, 28% of tensile strength decrease has been achieved after having holes for glass composites while the reductions were only 22%, 15% and 13% for glass composite laminates that have one, two and three aluminium layers, respectively. This reduction also becomes 4% for glass composite laminates that have one aluminium layer and thermoplastic particles and they exhibit typical ductile damage failures compared to other laminates. Further, the findings of numerical simulation for tensile strength and damage failure modes follow experimental results both qualitatively and quantitatively for notched composite laminates under tension loading.