Quasi-static Indentation Tests Research Articles

Characterisation and Application of Bio-Inspired Hybrid Composite Sensors for Detecting Barely Visible Damage under Out-of-Plane Loadings.

Traditional inspection methods often fall short in detecting defects or damage in fibre-reinforced polymer (FRP) composite structures, which can compromise their performance and safety over time. A prime example is barely visible impact damage (BVID) caused by out-of-plane loadings such as indentation and low-velocity impact that can considerably reduce the residual strength. Therefore, developing advanced visual inspection techniques is essential for early detection of defects, enabling proactive maintenance and extending the lifespan of composite structures. This study explores the viability of using novel bio-inspired hybrid composite sensors for detecting BVID in laminated FRP composite structures. Drawing inspiration from the colour-changing mechanisms found in nature, hybrid composite sensors composed of thin-ply glass and carbon layers are designed and attached to the surface of laminated FRP composites exposed to transverse loading. A comprehensive experimental characterisation, including quasi-static indentation and low-velocity impact tests alongside non-destructive evaluations such as ultrasonic C-scan and visual inspection, is conducted to assess the sensors' efficacy in detecting BVID. Moreover, a comparison between the two transverse loading types, static indentation and low-velocity impact, is presented. The results suggest that integrating sensors into composite structures has a minimal effect on mechanical properties such as structural stiffness and energy absorption, while substantially improving damage visibility. Additionally, the influence of fibre orientation of the sensing layer on sensor performance is evaluated, and correlations between internal and surface damage are demonstrated.

Experimental study on composite spherical-roof contoured-core (SRCC) sandwich panels under the V-shaped quasi-static indentation loading

The paper investigated the experimental study of composite spherical-roof contoured-core (SRCC) sandwich panels under a V-shaped quasi-static indentation (QSI) test. The carbon fiber, glass fiber, aramid fiber, hybrid carbon/aramid, and glass fiber chopped strand mat sheets were used to manufacture the composite cores, which used the hand layup and hot compression techniques. The polylactide (PLA) core was fabricated using fused deposition modelling (FDM). The V-shaped indenter had a 65° angle and was set at 1 mm/min as indentation speed in the experimental test. It was found that the maximum indentation deflection was 35.49 mm on the SRCC sandwich panel with a hybrid carbon/aramid core compared to other composite cores. Furthermore, it was localized fiber fracture, matrix damage, delamination, inwards fronds, and debonding damage mode on composite SRCC sandwich panels, which was visually shown at the central SRCC core unit cell. It is highlighted that aramid fiber and hybrid carbon/aramid materials can provide outstanding impact characteristics, which have great potential to be used as impact-resistant sandwich structures.

Experimental Investigation of Ice Loads on Structures during Quasi-Static Compression Tests

In polar ship hull structural designs, methods based on regulations are considered the most authoritative; however, they tend to be conservative and often exhibit a notable degree of redundancy. This study aims to evaluate the applicability of the empirical formula for ice load assessments by conducting a series of quasi-static indentation tests on scaled hull plates under laboratory-made ice blocks of different scales. The obtained data include ice loads, structural responses, and characteristics of ice pressure distribution. A detailed comparison of various formulas is provided, along with an examination of their differences and errors in comparison to experimental results. The objective of this paper is to offer technical support for ice load forecasting and assessment.

Effects of Seawater on Mechanical Performance of Composite Sandwich Structures: A Machine Learning Framework.

Sandwich structures made with fibre-reinforced plastics are commonly used in maritime vessels thanks to their high strength-to-weight ratios, corrosion resistance, and buoyancy. Understanding their mechanical performance after moisture uptake and the implications of moisture uptake for their structural integrity and safety within out-of-plane loading regimes is vital for material optimisation. The use of modern methods such as acoustic emission (AE) and machine learning (ML) could provide effective techniques for the assessment of mechanical behaviour and structural health monitoring. In this study, the AE features obtained from quasi-static indentation tests on sandwich structures made from E-glass fibre face sheets with polyvinyl chloride foam cores were employed. Time- and frequency-domain features were then used to capture the relevant information and patterns within the AE data. A k-means++ algorithm was utilized for clustering analysis, providing insights into the principal damage modes of the studied structures. Three ensemble learning algorithms were employed to develop a damage-prediction model for samples exposed and unexposed to seawater and were loaded with indenters of different geometries. The developed models effectively identified all damage modes for the various indenter geometries under different loading conditions with accuracy scores between 86.4 and 95.9%. This illustrates the significant potential of ML for the prediction of damage evolution in composite structures for marine applications.

Quasi-Static Penetration Properties of 3D-Printed Composite Plates.

This work investigated the impact and piercing load resistance (energy absorption capabilities) of 3D-printed composites plates manufactured by means of the Fused-Filament-Fabrication (FFF) technique. Two sets of reinforced composite plates were produced. The first set of plates was printed with short-carbon-fiber-reinforced polyamide-12, while the second set was reinforced with continuous fibers. The plates were tested with quasi-static indentation tests at various Span-to-Punch ratios and with three different indenter nose shapes (blunt, hemispherical, and conical). The quasi-static measurements were subsequently elaborated to estimate the energy absorption capability of the plates during a ballistic impact. The addition of continuous fibers increased the quasi-static energy absorption capability by 20-185% with respect to the short-fiber-reinforced plates. The quasi-static results showed that by including the continuous reinforcement in the plates, the normalized energy absorbed increased by an order of magnitude. Finally, a comparison with data from the literature concerning continuous-reinforced composite plates manufactured by means of traditional techniques was carried out. The comparison revealed that FFF-printed composite plates can compete with traditional composite ones in terms of both ballistic and quasi-static penetrating load conditions, even if limited by the lower fiber volume fraction. Thus, these findings confirm that this novel Additive Manufacturing technique is promising and worth investigating further.

Assessment of damage sequence in additive manufactured composite laminates under quasi-static out-of-plane loading

The understanding of the impact behaviour of additive manufactured continuous fibre reinforced polymers must start from the analysis of the damage mechanisms. In this investigation, the impact damage in a 3D-printed continuous carbon fibre reinforced polymer is studied by means of quasi-static indentation tests. The coupons are manufactured with Fused Filament Fabrication (FFF) using a thermoplastic resin. Three indentation displacement levels were tested, analysing different phases of the impact using X-ray Computed Tomography. The effects of fibre orientation were considered, establishing a comparison between one laminate with conventional orientations (0, 90, ±45) and one with disperse orientations. Results show a progressive damage generation influenced by the inherent defects of the manufacturing process, characterized by delamination growth and stiffness reduction. Fibre and matrix breakage only appear at the final stages when the laminate peak load is reached. The considered dispersed laminate shows less delaminated interfaces compared to the conventional one.

Advanced adhesive repairs and reinforcements for curved glass/epoxy composite laminates

This study investigates the repair of damaged curved glass/epoxy composite laminates through various adhesive reinforcements and adhesively bonded external patches. The experimental procedures involve fabricating laminates, conducting four-point bending tests, quasi-static indentation tests, and optimizing damaged areas. Results demonstrate the influence of repairs on curved beam strength and interlaminar tensile strength. Adhesive repairs with chopped fiber reinforcement outperform plain epoxy and particle fiber-reinforced repairs, preserving 51.28% of curved beam strength. Adhesively bonded external patches, both single and double, with chopped fiber reinforcement exhibit significant strength recovery 72.08% and 80.78% compared to virgin samples. The study emphasizes the effectiveness of adhesively bonded external patches, particularly those with chopped glass fiber reinforcement, in enhancing curved beam strength and interlaminar tensile strength. This research provides valuable insights for repairing angled structures, such as those in airplane components, showcasing potential applications of these techniques for structural maintenance.

Experimental Investigation of Quasi-Static and Dynamic Impact Resistance in Thin Wood Veneer Laminates

The incorporation of sustainability into the design of transport vehicles has become increasingly important in recent years. A low carbon footprint makes wood-based structures attractive to replace other lightweight materials such as aluminum or fiber-reinforced plastics. This paper investigates and compares the static and dynamic impact behavior of thin Beech wood veneer laminates in standardized mechanical tests. The results obtained from Quasi-Static Indentation (QSI) and dynamic Low-Velocity Impact (LVI) tests reveal similarities and differences with regard to load vs. displacement behavior, damage mechanisms, permanent deformation, and energy absorption. While yield strength and damage modes are comparable in both test cases, it is found that the bending stiffness is strain-rate sensitive. Plastic deformation in compression is identified as the governing mechanism for energy absorption. These results can guide the design of sustainable wood-based structures for future transport applications where a thorough understanding of impact and crashworthiness is important.

Exploring the electrochemical and mechanical properties of lithium-ion batteries in salt spray environments

With the pressing need to expedite the transition toward a greener marine industry, energy-efficient and eco-friendly lithium-ion batteries (LIBs) are increasingly favored. However, compared to land applications, marine environments pose unique challenges to the utilization of LIBs, thereby necessitating targeted safety measures. In this study, prismatic LIBs (PLIBs) are subjected to standard salt spray tests to emulate marine environments, and the resultant morphological changes and external voltage response of the batteries under the corrosion behavior are analyzed. Subsequently, the impacts of the salt spray environment on the electrochemical performance of PLIBs are assessed through a range of characterization techniques including scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), and charge-discharge test. Finally, quasi-static ball indentation tests are carried out on the corroded batteries to study the behaviors under mechanical abusive loading scenarios. Results reveal that the most prominent effect of the salt spray environment on the batteries is the occurrence of swelling, attributable to the imperfect sealing of the battery tabs. This study represents an innovative exploration of the viability of LIBs in the marine environments, providing fundamental theoretical guidance for early detection of battery corrosion and collision risks, as well as facilitating protective design considerations.

Quasi-static indentation responses of FMLs/2.5D woven carbon-fiber honeycomb sandwich structures under different structural parameters

Here, a new type of sandwich structure made of fiber metal laminates (FMLs) as facesheet and 2.5D woven carbon-fiber (CFRP) honeycomb as core was developed. The FMLs/CFRP honeycomb sandwich structures were subjected to quasi-static indentation tests to investigate the mechanical response with the variation of panel structure, honeycomb cell element size, honeycomb core wall thickness, and honeycomb core height. In addition to experiments, a finite element method (FEM) model was also created in ABAQUS/Explicit to analyze the damage mechanisms and failure modes of honeycomb sandwich structures under quasi-static indentation. Both the experimental and FEM simulation results revealed that the honeycomb sandwich structure underwent two different failure modes under quasi-static loading: localized damage dominated by indentation and global damage due to overall bending deformation. The combination of panel strength and honeycomb core strength determined the failure mode of the sandwich structure. Damage analysis of the honeycomb core showed that it mainly underwent fiber compression damage and matrix compression damage under quasi-static indentation. This study provides guidance to optimize the design of honeycomb sandwich structures.

A novel approach to enhance the mechanical behavior of glass epoxy laminates with sustainable recycled milled fillers

AbstractThe aerospace, automotive, and energy industries can use fiber‐reinforced composites due to their high specific strength and stiffness. However, unexpected external impacts in work cause internal damage and residual strength loss in composite structures. Another ongoing issue is the sustainable management of composite materials' end‐of‐life. The quasi‐static indentation properties of glass epoxy composites are investigated in this study using different kinds of novel filler materials that are recycled from old composite materials: recycled milled carbon (rmCF), recycled milled Kevlar filler (rmKF), and an innovative hybrid filler (rmBF) composed of recycled milled carbon and Kevlar fillers (rmBF). Surface roughness and hardness studies assessed the quasi‐static indentation (QSI) response of neat glass epoxy and glass epoxy composites loaded with fillers using indentation force, absorbed energy, residual dent depth, and evolution of damage area. Compared to the baseline samples, the rmCF composites performed exceptionally well, showing a 16% increase in peak force, a 59% decrease in damaged area, and a 6.32% and 22.5% reduction in surface roughness, respectively (Ra and Sa). After QSI tests, rmC filler samples had 26.8% higher residual flexural strength than neat glass epoxy composites in a three‐point bending test. Through toughening mechanisms like filler interlocking and bridging, micrographs captured using a scanning electron microscope (SEM) showed that recycled fillers provide a higher level of stiffness, better energy dissipation, less damaged area, and overall improved hardness.Highlights Recycled milled carbon (rmCF) and Kevlar hybrid fillers (rmKF) have been integrated into glass/epoxy composites. The damage tolerance of glass epoxy composites was as a whole significantly improved by the rmCF integration. The Kevlar fillers' inadequate adhesion and interlaminar shear strength were compensated for by the Hybrid fillers (rmBF). Micrographs taken with a scanning electron microscope (SEM) clearly show the fillers' role in the resistance to damage propagation processes.

Optimizing Crash Performance in Aluminum-Polyamide Hybrid Material Systems: Insights from Drop-Weight and Quasi-Static Indentation Testing

Optimizing Crash Performance in Aluminum-Polyamide Hybrid Material Systems: Insights from Drop-Weight and Quasi-Static Indentation Testing

Mechanical characterization of 3/2 fibre metal laminate materials

Development of lightweight materials onto vehicle bodies, especially in the automotive sector is seen as one of the best alternative solutions in order to reduce fuel consumption and decrease harmful emissions produced by the emission. Reducing in weight of a vehicle can improve fuel efficiency with no prejudice to safety strength requirements. Fibre metal laminate (FML) is hybrid composite structure based on thin sheet of metal alloys and plies of fibre reinforced polymeric materials which offer the ability of superior mechanical properties such as lightweight, high fatigue growth resistance and high strength and stiffness. Multi-material auto bodies will allow optimal material selection in structural components for higher performance and lower cost. This study aims to fabricate and investigate the failure behaviour of a 3/2 layer fibre metal laminate subjected to the quasi-static indentation test. The FML is constructed from aluminium 2024-T3 and layered with composite materials CFRP, GFRP and SRPP. The crosshead speed test analysis ran in different parameters on 1 mm/min, 5 mm/min, 10 mm/min and 50 mm/min, respectively in quasi-static indentation test. The experimental performances of each specimen were compared to predict the behaviour and performance of the FML composite. The test indicates that varying crosshead speeds have influenced the affected region of the FML, causing debonding on the laminate as a result of continued loading.

Characterization of Behavior of Lithium Ion Battery Under Vibration and Shock Conditions

Electric vehicles are being developed to address environmental issues such as air pollution caused by vehicles that use fossil fuels. As a result, the efficiency and performance of the battery, which is a crucial component of an electric vehicle, have become increasingly important. Research on the electrical behavior and heat of the battery is currently being actively conducted. However, with the improvement of battery efficiency and the increase in mass production, safety issues have arisen.Numerous studies are being conducted on battery safety, such as thermal runaway resulting from the deformation and failure of battery components, including the cathode and anode, caused by loads acting on the battery. Recently, research on stress factors caused by random vibrations and shocks that reflect actual vehicle operating conditions has made significant progress. For instance, Brand et al. conducted random vibration and shock tests based on the UN 38.3 standard test, evaluating durability based on the increase in resistance that occurs during the test1). Similarly, Berg et al. tested cylindrical cells with random profiles, according to the SAE J2380 standard and an even more severe profile2). After the test, they mainly observed the deformation of the tab, rather than the jellyroll of the battery. Yun et al. created a numerical model with the Representative Volume Element (RVE) model at the module level, obtaining the effective elastic modulus from the RVE model of the cell level and applied it to the module, so that the behavior of the jellyroll was not described at the cell level3). However, previous studies have mainly analyzed battery degradation caused by vibration and shock tests based on electrical characteristics. Hence, further research on damage and numerical models of battery cell levels that cause degradation according to random vibration and shock tests is required.In this study, anode, cathode, and separator of a pouch cell were prepared in form of a rectangular specimen with notch to conduct vibration and shock tests using the UN 38.3 standard test. The three battery cell components were stacked on a vibration jig, as in a real pouch cell. Scanning electron microscope (SEM) was used to investigate whether a fracture like crack occurred due to a vibration test near the notch of the specimen with a. Additionally, a numerical model for the pouch cell was constructed using a representative sandwich (RS) model4), and the predicted fracture behavior of the battery components according to the vibration and shock test was analyzed. The RS model provided a simplified representation of the internal structure of a battery cell, and the mechanical parameters required to build the RS model were obtained through tensile tests of battery cell components. Brand, Martin J., et al. "Effects of vibrations and shocks on lithium-ion cells." Journal of Power Sources 288 (2015): 62-69.Berg, Philipp, et al. "Durability of lithium-ion 18650 cells under random vibration load with respect to the inner cell design." Journal of Energy Storage 31 (2020): 101499.Jin Chul Yun. "Study on mechanical behavior of lithium ion battery using multi-scale analysis.". (2017). Pohang University of Science and Technology, PhD dissertationZhang, Chao, et al. "A representative-sandwich model for simultaneously coupled mechanical-electrical-thermal simulation of a lithium-ion cell under quasi-static indentation tests." Journal of Power Sources 298 (2015): 309-321.

The study on the influence of different damage introduction methods on the damage characteristics of aircraft composites

Composite materials have advantages incomparable to traditional metal materials. However, they are more sensitive to impact damage and their mechanical properties decrease significantly after impact damage. Therefore, it is of great significance to study the energy absorption, mechanical response and damage mechanism of materials in different ways. To study the influence of different punch diameter sizes on the material damage characteristics, three kinds of punch diameters of 12.7 mm, 16 mm and 25.4 mm are selected to carry out the quasistatic indentation test and drop hammer impact damage test on the test pieces respectively. The material damage caused by different punch sizes under two damage introduction methods is analyzed. Damage introduction was carried out on the test piece with the same layering through two methods: quasi-static indentation and drop hammer impact. The damage depth, damage area and residual strength were compared after damage introduction. The difference between quasistatic indentation and drop hammer impact damage introduction was verified by comparing the damage characteristics to each other. The results show that with the increase of punch diameter size, the damage area decreases and the residual strength of the material increases. In addition, the test results of different punch diameter sizes under the two damage introduction methods have the same change trend, which proves that the impact of punch size on the material damage characteristics has no obvious relationship with the damage introduction method. Quasi-static indentation and drop hammer impact damage have no significant difference in the residual strength of materials after damage, which verifies the equivalence of static indentation and damage introduction.

Impact resistance and damage mechanism of polyurea coated CFRP laminates under quasi-static indentation and low velocity impact

In this study, polyurea coating has been applied to improve the impact resistance of carbon fiber reinforced plastics (CFRP) battery pack housing under automotive crash condition. The quasi-static indentation test and low velocity impact test were carried out to study the impact response of polyurea coated unidirectional and plain woven CFRP laminates with three coating methods. The impact velocity was selected from 10−4 m/s to 4.5 m/s. In addition, damage mechanism and failure modes of the laminates were analyzed, focusing on the identification of dominant damage modes and crack evolution. It was demonstrated that thin polyurea coating can improve the impact resistance of both unidirectional and plain woven CFRP, while the former was more significant than the latter. The specific energy absorption had 94% and 51% increment under low velocity impact and quasi-static indentation. The front coating method was the best polyurea coating method. Results also revealed that the polyurea coating increased the damage area and fracture crack of polyurea coated CFRP laminates with different damage mechanisms. This study confirms that the use of polyurea coated CFRP laminates is an interesting and promising structure candidate for crash safety design and lightweight design of battery pack housing.

Experimental analysis of the quasi-static penetration test on fiber metal laminated plate reinforced by nano-silica

FMLs are lightweight hybrid materials that possess specific static properties, impact resistance, fracture resistance, and fatigue resistance. These characteristics make FMLs highly desirable for various applications in the transportation industry (Hu et al., 2015 Dec 1) [2].The present study aims to scrutinize the energy absorption and strength characteristics of a kind of Fiber Metal Laminate (FML) reinforced with Nano silica (0, 0.3, 0.6, and 0.9 wt %) that is fabricated from braided fiberglass and carbon fiber sleeve and aluminum 2024-T3. Sleeve-type braided fiberglass, carbon fiber and highly adhesive resin were introduced as interlayers. The arrangement of FMLs layers was in 2 types, first AL/Glass/Glass/Glass/Glass/AL and second AL/Glass/Carbon/Carbon/Glass/AL. The produced FMLs were tested to evaluate the behavior and strength characteristics under quasi-static indention. Quasi-static indentation test performed with spherical head penetrators at a 5 mm/min rate. The experiment continued until the indenter fully penetrated the specimen. These FMLs crushed progressively and are unlikely to fail under catastrophic failure, although specimens with 0.6% Nano silica in glass fiber and specimens with 0.3% in the glass and carbon fiber have better performance. A comparison of the results of glass FMLs with hybrid FMLs shows that Nano silica-reinforced glass fibers have achieved better results than hybrid fiber. To study the structure of amplified FMLs, electron microscopy (SEM) imaging was used which showed that in FMLs with better results, Nano silica was evenly distributed on the layer of epoxy resin. The results also indicate that the mechanical performance of a new FML has a good potential to be applied as a new and efficient energy absorber.

Effect of solution-blown nanofibrous web on quasi-static punch shear test results and quasi-static indentation behavior of carbon fiber-reinforced epoxy matrix composites

This study investigated the effects of the nanofiber interlayer in carbon fiber-reinforced epoxy matrix composites on quasi-static loading behaviors such as quasi-static punch shear (QS-PST), quasi-static indentation (QSI), and short-beam shear (SBS) loading. The solution-blowing technique was used to produce polyamide-6 (PA6) nanofiber with 1 g/m2 areal density. A 2×2 twill weave carbon fiber fabric with an areal density of 200 g/m2 was covered with solution-blown nanofibers. The vacuum-assisted resin transfer molding (VARTM) method was used to manufacture nanofiber interlayered composites and non-interlayered composites. QS-PS experiments were conducted at three different span to punch ratios (SPR), namely 1.1, 2, and 4. The PA6 nanofiber had a synergetic effect on the composite structure. In the QS-PST experiments, it increased the amount of work achieved by the specimen at rates of 29.5%, 13.5%, and 5.66% for SPR 1.1, 2, and 4, respectively while it provided increases in the maximum force at rates of 15.3%, 15%, and 5.7%, respectively. Additionally, the PA6 nanofiber contributed to the composite material properties determined based on the QSI test including the maximum force, punch crush strength, crush stiffness, and through-thickness modulus at rates of 7.5%, 7.56%, 2.72%, and 5.76%, respectively. Finally, an increase at a rate of 11.43% was determined in the SBS strength of the nanofiber interlayered composite, while it showed an increase in maximum force observed during the SBS experiment at a rate of 12.28%. The enhancements of mechanical properties of structural composites make them more reliable for high technology applications like aerospace, and automotive.

The effect of nanoclay on the performance of basalt-epoxy facesheet and foam core sandwich panels

It has been reported that the properties of a foam-based sandwich panel can be enhanced by incorporating nanoclay into the facesheet or foam core. In this study, an attempt was made to disperse nanoclay into the epoxy adhesive so as to bond the facesheet with the core. The sandwich panel in this study was fabricated using a basalt/epoxy laminate as the facesheet and polyvinyl chloride foam as the core material. The characterisation results through flexural and quasi-static indentation tests revealed that the infusion of nanoclay led to an increase of up to 34% in the bending strength, 51% in the core shear strength, and 72% in energy absorption. In addition, the nanoclay-reinforced sandwich panel showed a slightly higher sound absorption coefficient than the control specimen without nanoclay. Another interesting observation from the flexural and quasi-static indentation tests was that the addition of nanoclay also influenced the failure behaviour and the size of the damaged area. The superior energy and sound absorption characteristics make the foam-based sandwich panel a potential material for structural applications requiring acoustic insulation.

Study of damage behavior and repair effectiveness of patch repaired carbon fiber laminate under quasi-static indentation loading

Damage caused due to low-velocity impacts in composites leads to substantial deterioration in their residual strength and eventually provokes structural failure. This work presents an experimental investigation on the effects of different patch and parent laminate stacking sequences on the enhancement of impact strength of Carbon Fiber Reinforced Polymers (CFRP) composites by utilising the adhesively bonded external patch repair technique. Damage evolution study is also performed with the aid of Acoustic Emission (AE). Two different quasi-isotropic configurations were selected for the parent laminate, viz., [45°/45°/0°/0°]s and [45°/0°/45°/0°]s. Quasi Static Indentation (QSI) test was performed on both the pristine laminates, and damage areas were detected by using the C-scan inspection technique. Damaged laminates were repaired by using a single-sided patch of two different configurations, viz., [45°/45°/45°/45°] and [45°/0°/0°/45°], and employing a circular plug to fill the damaged hole. Four different combinations of repaired laminates with two configurations of each parent and patch laminate were produced, which were further subjected to the QSI test. The results reveal the effectiveness of the repair method, as all the repaired laminates show higher impact resistance compared to the respective pristine laminates. Patches of [45°/0°/0°/45°] configuration when repaired by taking [45°/45°/0°/0°]s and [45°/0°/45°/0°]s as parents exhibited 68% and 73% higher peak loads, respectively, than the respective pristine laminates. Furthermore, parent and patch of configuration [45°/0°/45°/0°]s and [45°/0°/0°/45°], respectively, attain the highest peak load, whereas [45°/45°/0°/0°]s and [45°/45°/45°/45°] combinations possess the most gradual decrease in the load.