Fracture Of Composites Research Articles

The Characterization of the Sandwich Composite Consisted of Coconut Fibre-Polyester Resin and its Variations of Wood Core

The traditional fishing vessels in Indonesia are usually made of wood material. The weakness of this vessel material is that it is easily weathered when exposed to seawater. For this reason, it is necessary to have vessel material engineering from composite sandwiches. This study aimed to prepare and investigate the flexural test, impact test, optical microscopy (OM), and scanning electron microscopy (SEM) observations of sandwich composites based on coconut fibre-polyester resin and wood core. The fabrication uses a hand lay-up method with a constant volume fraction (20% coconut coir fibre) and wood core variations type. The primary wood variations used are albizia chinensis, mahogany, shorea, and camphor. The Surface modification of fibre and wood core was conditioned without treatment and with treatment with about 5% NaOH solution for 2 hours. The study showed that the highest bending and impact strength was sandwich composite with camphor wood cores with alkali treatment for 39.75 MPa and 37.22 J/cm2, respectively. The OM observations showed that the core and skin interface area failed to delaminate after flexural and impact tests. SEM observations also showed thatthe bond alkalization treatment between the matrix and the fibres was quite good. In the composite skin fracture area, there is a lot of fibre brake, and a little thread pulls out. The skin matrix also shows the presence of voids. Generally, this sandwich composite is feasible for application as a material for traditional fishing vessels.

Composition optimization of PMMA base denture reinforced with different percentages of Nano Hydroxyapatite and alumina particles to obtain highest KIc and KIIc values using hybrid IWO/PSO algorithm

Composition of three-phase dental denture (Polymethyl methacrylate or PMMA + Nano Hydroxyapatite + Nano Alumina) was optimized using hybrid IWO/PSO algorithm to obtain the highest KIc and KIIc. First, initial fracture toughness tests were performed on nine groups of PMMA base dentures with different percentages of ingredients. Symmetric single edge notch beam and asymmetric three-point bend beam with inclined crack were used for KIc and KIIc testing, respectively. The initial design parameters were considered as: {75–100% PMMA, 0–10% Nano Hydroxyapatite and, 0–15% Nano Alumina}. As the initial guess values for starting the hybrid optimization algorithm, B-spline curves (as the cost function) were fitted to the experimental results of both modes I and II. Then the IWO/PSO algorithm was run to find the optimum composition and maximum fracture toughness value of each mode. The best KIc was found for the composition of {78.5% PMMA + 9% Nano Hydroxyapatide + 12.5% Nano Alumina}. Similarly, using the hybrid IWO/PSO algorithm the optimum composition of {83.4% PMMA + 8.7% Nano Hydroxyapatide + 7.9 % Nano Alumina} was obtained to gain the highest KIIc. The experimental fracture toughness values obtained from the proposed compositions via employing the hybrid algorithm were approximately 40% higher than the all tested nine groups of PMMA base dentures under both modes I and II. The fracture toughness ratio KIIc/KIc of the optimum mix-designs predicted by the hybrid algorithm was equal to 0.78 and showed good agreement with the experimental KIIc/KIc ratio. The fracture toughness for any desired mixed mode condition can also be predicted in-terms of the KIc and stress intensity factors and T-stress of the desired mode mixity.

Experimental investigation of wrapped composite X‐joints under uniaxial and multi‐axial loading conditions

AbstractCircular hollow section (CHS) multi‐membered structures, such as off‐shore wind turbine jackets and floating wind structures, face significant challenges under multiaxial loads. Wrapped composite joints have emerged as a promising alternative to conventional welded joints, offering superior structural and fatigue performance in previous pilot tests. This paper presents an experimental study on the failure mechanisms and load‐bearing capacity of wrapped composite joints under multi‐axial monotonic loading, using the Hexapod a six‐degree‐of‐freedom testing machine. The research question addressed in this study is to investigate the effectiveness of wrapped composite joints in resisting multi‐axial loads, and to understand the underlying failure modes. The experimental results demonstrate that the joints exhibit excellent resistance to uniaxial tension, uniaxial bending, and multi‐axial tension + bending loading, with failure modes including interfacial debonding, delamination, composite fracture, and steel yielding. Digital Image Correlation (DIC) and embedded optical fibers were used to monitor surface and interface strain. These findings suggest that wrapped composite joints offer significant resistance to multi‐axial loading.

Study on bonding behavior of FRP grid-ECC composite layer and concrete with quantitative interface treatment

The interface bonding effect can determine the overall mechanical properties of the reinforced components to a large extent. This paper proposed an improved interface treatment method between FRP grid-ECC composite layer and concrete that could quantify the interface roughness, and the effect of this method on the interface bonding behavior was investigated through the double-shear test. Four groups of twelve specimens, including one group without interface treatment and three groups with different interface treatment rates, were tested to reveal their bond-slip relationship. The test results demonstrated that the improved method was effective, with the ability to inhibit interface peeling; moreover, as the interface treatment rate increased, the bonding effect enhanced, and the failure mode gradually transitioned from critical fracture to composite layer fracture. Furthermore, the bond-slip model and the bearing capacity formula for the improved method were established, and the predicted values were well matched to their corresponding test results.

Determination of the effects of nanoparticle reinforcements on mechanical and composite surface fractures in joints bonded with epoxy adhesives

Various studies are carried out to increase the strength of the joints made with adhesives. One of these studies is to investigate the use of nanoparticles as reinforcement elements in adhesives. In this study, the tensile strength of the bonding joints made by adhesives DP410, DP460 and DP490 epoxy adhesives at the rates of 0.1, 0.2, 0.3 and 0.4% wt. of the graphene nanoparticles (GNP) were investigated. AA5754 aluminum alloys and glass fiber reinforced composites were used as adherent and patches, respectively. Tensile tests were carried out to determine the effect of reinforcement ratios on adhesive bonds. After the tensile tests, macro and scanning electron microscopy (SEM) images were taken to examine the adhesion damage between nanoparticle, adhesive and adherent surfaces. In the results of the tensile test experiments, the tensile strength of all the joints in which the reinforcement element is used was higher than the non-reinforced bonding. The highest tensile strength in GNP-reinforced joints using DP410 and DP490 adhesives was obtained as 5674.4 and 4837.4 MPa, respectively, at 0.2% wt. reinforcement rate. However, the highest tensile strength of all experiments was obtained as 6154.4 MPa in DP460 adhesive, where 0.3% wt. reinforcement ratio was used. In the damage analyses made after the tensile tests, it was observed that there were fiber breaks in the glass fiber composite used as the patch material in the bonding joints, where homogeneity was formed between the surfaces of the GNP and the epoxy adhesive. Especially, this situation occurred in the joints where 0.2% wt. in DP410 adhesive and 0.2% wt. and 0.3% wt. of reinforcement ratios of DP460 adhesive joints were used. Finally, in the fatigue tests, the GNP particle reinforcement increased the fatigue life of the adhesive joints.

Experimental Study on the Dynamic Fracture Characteristics of Mortar-Rock Interface Zones with Different Interface Inclinations and Shapes.

There has been little research on the impact resistance of mortar-rock slope protection structures. To ensure that the mortar-rock interface has good adhesion properties under the action of impact loading, in this paper, based on fracture mechanics theory, a theoretical impact model was established for mortar-rock binary material. Dynamic fracture tests were carried out on mortar-rock interfaces using the split-Hopkinson pressure bar (SHPB) system. The Brazilian disc (CSTBD) specimen was prepared with one half in granite and the other half in mortar. The specimen used for the dynamic impact test was 48 mm in diameter and 25 mm thick. The effects caused by the change in interface inclination and interface shape on the dynamic fracture mode were discussed. The dynamic model parameters were obtained for different inclination angles and interfaces. The results show that both the interface inclination and interface shape have significant effects on the dynamic mechanical properties of the mortar-rock binary material. The fracture modes of the mortar-rock specimens can be classified into three types. When the interface inclination is 0°, the specimen shows shear damage with an interface fracture; when the interface inclination is in the range of 0-90°, the dynamic splitting strength of the mortar-rock material increases with increasing interface inclination, and the interface undergoes composite fracture; and when the interface inclination is 90°, the dynamic splitting strength of the specimen reaches its peak, and the interface undergoes tensile fracture. The mortar-rock interface damage follows the M-C criterion. The roughness of the interface shape has a large influence on the dynamic splitting strength of the specimens. The rougher the interface shape, the higher the interface cleavage strength and the higher the peak load that causes the material to damage. The results of this study can provide a reference for the design of mortar-rubble structures to meet the demand for impact resistance and have strong engineering application value.

Mechanical characteristics and fracture mechanisms of fissured rock mass samples with various opening sizes

To obtain the effect of fracture failure mechanics characteristics and behavior of brittle rock masses on the compound factors of fissure openings and inclination, uniaxial loading tests were performed on single-fissured rock-mass specimens with different openings using a rock mechanics test machine. The test results show that with the increase in fissure openings, the fissured rock-mass peak strength variation behavior with the increase in fissure inclination angle changes from first decreasing and then increasing to gradually increasing, and the angle at the minimum value of peak strength shifts from 45° to 0°. At the same fissure angle, the peak strength of the fissured rock mass decreases with the increase in the fissure opening size. The greater the opening size of the prefabricated fissure, the smaller the peak strength of the fissured rock mass and the greater the influence of changes in the fissure inclination angle. The elastic modulus of the fissured rock-mass specimen shows a positive correlation with the fissure inclination angle and a negative correlation with the fissure opening size. Combined with the neighborhood stress field analysis of the open fissure tip, the criterion of composite fracture under tension failure is established, and the linear relationship between the stress intensity factors KI and KII is verified. The criterion of composite fracture of open fissures under shear failure is also identified, which is based on the linear relationship between the stress intensity factors.

Tensile properties of flexible carbon nanotube film/PVA composite at various strain rates

AbstractThe quasi‐static tensile properties of carbon nanotube (CNT) composites have already been extensively studied, while their impact tensile properties under high rates have rarely been investigated. In this work, CNT film/PVA composites were prepared by impregnation and hot press curing, whereas CNT films were prepared by floating catalyst chemical vapor deposition (FCCVD). Instron 3365 and the miniaturized split Hopkinson tensile bar (SHTB) were used for tensile tests at various strain rates. The results show that the tensile properties of PVA‐impregnated CNT film are significantly improved, and the strain rate effect is remarkable. The tensile properties are best when the mass fraction of PVA is 1.5%. At a low strain rate of 0.001 s−1, the maximum stress and energy absorption (EA) of CNT composites are 502.5 MPa and 63.6 MJ/m3, respectively. And at the high strain rate of 3100 s−1, the maximum stress and EA of CNT composites are 969.0 MPa and 166.4 MJ/m3, respectively. Scanning electron microscopy (SEM) was used to observe the failure morphologies at tensile fracture of composites under different strain rates. At low strain rate, the failure mode is the pulling fracture of tube bundles and the crushing of polymers, while at high strain rate is the folding and spring back of tube bundles, as well as the debonding of polymers.

Acoustic and mechanical tests of sandstone-shale composites in Songliao Basin and prediction of uniaxial compressive strength

Rock uniaxial compressive strength is a vital rock mechanics parameter, which accurate assessment is critical for high-efficiency unconventional reservoir development. However, its realization for standard cores is quite problematic due to difficulties and high costs related to the collection and preparation of samples. Unconventional fracturing treatment have evolved from single to composite lithology. This study collected shale and sandstone samples at different bedding angles (0°, 45°, 90°)to prepare the sandstone-shale composite samples at different interlayer ratios. It measured the prepared composites’ longitudinal wave and transverse wave velocities with ultrasonic velocity testing. The uniaxial compressive strength of the sandstone-shale composites with various bedding angles were tested via a servo rock triaxial testing machine. The anisotropic characteristics of the prepared sandstone-shale composites with various bedding angles were analyzed, and relation between the uniaxial compressive strength of the anisotropic sandstone-shale composite and P-wave velocity was derived and experimentally validated. The results show that: the wave velocity test results of the sandstone-shale combination show that with the increasing proportion of shale, the wave velocity of the longitudinal wave and the transverse wave both increase; The wave velocity results of different bedding planes in shale are as follows: Vp(0°)> Vp(45°)> Vp(90°). The average P-wave and S-wave velocities at 45° are 0.92, while the average P-wave and S-wave velocities at 90° are 0.85 compared to 0°; the P-wave and S-wave anisotropy of shale are both 0.14, and the shale shows significant anisotropy. In the sandstone-shale composite, the uniaxial compressive strength gradually decreases and the strain increases with the increase of shale proportion. The value of uniaxial compressive strength is UCS(0°) > UCS(90°) > UCS(45°). Based on the P-wave modulus, a fitting relationship formula for the uniaxial compressive strength of sandstone-shale composites with different bedding angles and interlayer ratios was established and verified. The anisotropic strength predictive formula established based on experimental data is simple, precise, and easy to obtain, with strong practicability. The present research results can provide proper technical support for sandstone-shale composite fracturing optimization and reservoir development.

An adaptive coupling approach of local and non-local micromechanics

This study proposes a novel method for predicting the microcrack propagation in composites based on coupling the local and non-local micromechanics. The special feature of this method is that it can take full advantages of both the continuum micromechanics as a local model and peridynamic micromechanics as a non-local model to achieve composite fracture simulation with a higher level of accuracy and efficiency. Based on the energy equivalence, we first establish the equivalent continuum micromechanics model with equivalent stiffness operators through peridynamic micromechanics model. These two models are then coupled into a closed equation system, and a transition region is introduced to achieve a smooth transition between them. A composite strength-induced adaptive algorithm is introduced to solve the unified model. Numerical examples for particle reinforced composites are considered to show the accuracy and performance of the present method. The micromechanics-based coupling method has the potential to efficiently simulate the microcrack propagation in various complex composite materials.

Mechanical behaviour and acoustic emission characteristics of basalt fibre mortar rubble under uniaxial cyclic compression

To investigate the effect of basalt fibre (BF) content on the mechanical behaviour and damage characteristics of mortar rubble under cyclic loading, uniaxial compression tests and cyclic loading and unloading tests were carried out on specimens fabricated with different BF volume fractions. Based on damage mechanics theory, a damage ontology model of BF mortar rubble was developed. The damage of BF mortar rubble under cyclic loading was identified and analysed using acoustic emission (AE) techniques, and parameters such as the Felicity ratio (FR), ratio of the RA (rise time/amplitude) and the average frequency (RA/AF), response ratio, b-value and peak frequency were used to characterise the failure mechanism of BF mortar rubble. The results of this study revealed that the incorporation of BF increased the compressive strength by 9.3%-14.2%. The response ratios of the initial cycles were 91.2, 53.4 and 24.4 when the BF content was 0.2%, 0.3% and 0.4% respectively. The incorporation of BF helps to delay the onset of critical damage values. The peak frequency signals are concentrated in the region of 50 kHz and 160 kHz. the 50 kHz frequency represents the appearance of fractures in the matrix and the 160 kHz frequency signal represents the occurrence of brittle fractures in the aggregate. The FR trend was a good predictor of damage to the mortar rubble. The damage mode of the mortar rubble changed from tensile fracturing to composite fracturing due to the addition of BF. The performance optimisation concept of mortar rubble proposed in this study provides a reference for the optimal design of BF mortar rubble and thus has a strong application value.

Fractographic analysis of composite joints under cryogenic conditions

Fiber-reinforced polymer matrix composites are often alternative materials for aerospace structures applications where high strength and stiffness at low weight are mandatory design requirements. However, there are still open issues related to thermal effects on composite parts' mechanical properties and fracture behavior, particularly under cryogenic conditions. This work aims to investigate the fracture aspects of carbon fiber composite joints made with co-curing, co-bonding, and secondary bonding technologies when subjected to cryogenic conditions. A detailed study was carried out on their mechanical performance under Mode I and Mixed Mode I/II loading by performing interlaminar fracture tests at −54 °C. Microscopy techniques were applied to better understand the failure mechanisms observed for each bonding technology. The manufacturing process has a direct influence on the crack propagation of the laminates at cryogenic temperature. The post-cure process results in a brittle behaviour for CB and SB composite joints tested at cryogenic temperature leading to significant reductions in the fracture toughness values. The CC composite joints exhibited a tougher behaviour in comparison to CB and SB composite joints. This is mainly due to the fact that these joints are not post-cured and the presence of an interlayer that delays crack propagation.

Characteristics, logging identification and major controlling factors of bedding-parallel fractures in tight sandstones

More and more tight oil and gas exploration practices show that bedding-parallel fractures (BPFs) are closely related to hydrocarbon migration and accumulation. However, there is still a lack of studies on the detailed characterization, the logging identification method and the major controlling factors of BPFs. The tight sandstones in the northern Sanbian of Ordos Basin have developed numerous BPFs which are typical research objects. In this study, the development characteristics and oil-bearing of BPFs were firstly analyzed based on cores, thin sections and image logs. Then, constrained by the BPFs appearing in cores and image logs, the identification method of BPFs was established by conventional log curves. Finally, the major controlling factors for the formation of BPFs were discussed. Resultsshow that the oil-bearing of BPFs is markedly better than high-angle fractures (HAFs), which indicates that BPFs have a great significance to tight oil migration and accumulation in the northern Sanbian. The bedding-parallel fractures index (BPFI), which consists of the composite fracture index (CFI), fracture dip index (FDI) and principal component analysis (PCA), can identify the BPFs of tight sandstones, and the identification rate can reach 85% with the detection result of image logs. Fine sandstones with parallel bedding and cross bedding which easily enriched mica, underwater distributary channel sedimentary microfacies with comparatively strong hydrodynamic conditions, and a certain mudstone thickness that can produce differential compaction overpressure are the major factors affecting the development of BPFs.

Effect of Acetylation of Two Cellulose Nanocrystal Polymorphs on Processibility and Physical Properties of Polylactide/Cellulose Nanocrystal Composite Film.

Polylactide (PLA) has become a popular alternative for petroleum-based plastics to reduce environmental pollution. The broader application of PLA is hampered by its brittle nature and incompatibility with the reinforcement phase. The aim of our work was to improve the ductility and compatibility of PLA composite film and investigate the mechanism by which nanocellulose enhances PLA polymer. Here, we present a robust PLA/nanocellulose hybrid film. Two different allomorphic cellulose nanocrystals (CNC-I and CNC-III) and their acetylated products (ACNC-I and ACNC-III) were used to realize better compatibility and mechanical performance in a hydrophobic PLA matrix. The tensile stress of the composite films with 3% ACNC-I and ACNC-III increased by 41.55% and 27.22% compared to pure PLA film, respectively. Compared to the CNC-I or CNC-III enhanced PLA composite films, the tensile stress of the films increased by 45.05% with 1% ACNC-I and 56.15% with 1% ACNC-III. In addition, PLA composite films with ACNCs showed better ductility and compatibility because the composite fracture gradually transitioned to a ductile fracture during the stretching process. As a result, ACNC-I and ACNC-III were found to be excellent reinforcing agents for the enhancement of the properties of polylactide composite film, and the replacement some petrochemical plastics with PLA composites would be very promising in actual life.

A novel SiC composite material infiltrated by basalt glass-ceramic with a high hardness

New high-performance materials for environments with high abrasive and erosive loads resistant are in a great demand for the modern industry. For the first time, a composite material obtained by infiltration of SiC porous oxide bonded preform with a basalt rock melt at a temperature of 1400 °C in air was proposed. The produced composite material significantly reduces porosity from 31.0 to 1.2%. Interestingly, an aluminosilicate phases crystallizes on the surface of SiC grains meanwhile the migration of Ca and Fe to the melt basalt volume due to atomic radii mismatch with the forming phases. The crystallinity of the basalt glass matrix obtained by petrurgical method is 66.9%. All together allows to improve hardness of the obtained composite material SiC/basalt glass-ceramics from 2.6 (preform) and 6.8 (basalt glass ceramics) to >9.6 GPa. The composite material fracture toughness (K1c ∼ 0.85 MPa·m1/2) also increases in comparison to a highly fragile basalt glass ceramics matrix. Thermal expansion coefficient value of the produced composite material is close to the dense polycrystalline SiC one and no sample destruction was observed caused by materials TEC mismatch.

Overview of Electric Discharge Machining of MachineTooled Ceramics and Ceramic-Based Composites

Accordingly, many engineering designers have improved the wear friction performance of such materials. Also, the use of polymers as reinforcements in their endeavors has been done to improve intrinsic performance. Intrinsic properties played an important role in intrinsic polymer orientations, improving the cohesion of some reinforcement while at the same time worsening those Effects Woven glass, carbon and amethyst polymeric composites Inter-laminar shear strength and abrasion composites samples. Wear properties are calculated using machine and testing machine in computer aided universal testing. Fracture of composites showed surface modifications for Group bonding. The mechanical properties of basalt are better than glass reinforced composites the result of the study confirms the applicability of basalt as a reinforcing agent in polymer composites. Hybrid Mechanical Processes Ultrasonic assisted laser/water jet machining processes are used to solve machining problems related to insulating ceramics such as ultrasonic assisted discharge machining, discharge milling, electro-chemical discharge machining and powder hybrid discharge machining and discharge diamond grinding. Processes can create complex patterns in spark discharges. An attempt has been made here to compare the convex stability with the above cast iron and polymer impregnated mechanical properties.

Investigation of the effect of compacting mode parameters of a carbon-aluminum wire preform on the strength of the produced compact

The effect of the modes of compaction of a carbon-aluminum composite of a wire preform on its microstructure, properties, and nature of fracture has been studied. It is shown that with an increase in the temperature, load, and holding time, the volume fraction of pores decreases, and the fraction of fiber increases, which leads to an increase in the composite strength. In all cases, the shape of the fracture surface indicates the brittle nature of the composite fracture.

Fracture of V-notched natural rubber composites used in heavy-duty tire tread

Natural rubber-based composites have proven efficacy as candidate materials for heavy-duty tire tread. The mechanical properties of these composites depend on the type of filler and their loading; thus, a comparative investigation of material properties was carried out in this study for carbon black and silica-filled natural rubber composites. The mechanical properties of silica-filled rubber composites with silane loading of 16 wt% of silica were found to have optimum mechanical and fracture properties, but carbon black had better reinforcing efficacy after 300% elongation. The experimental investigations and finite element analysis show that the J-integral decreases with increasing crack opening angle. A decrement of 22% is observed in J-integral when crack opening angle varies from 300 to 600 for rubber composites with a pre-crack length of 5 mm. The geometry factor depended on the type of filler when the crack opening angle is increased for the composites having a large pre-crack length. We envisage that this study will be helpful for rectifying design faults of different rubber composites used in industrial applications, especially for passenger and heavy-duty tires.

Lowering serum urate with urate-lowering therapy to target and incident fracture among people with gout.

Gout is associated with a higher risk of fracture; however, the associations of hyperuricemia and urate-lowering therapy (ULT) with the risk of fracture have been inconsistent. We examined whether lowering serum urate (SU) levels with ULT to a target level (i.e., <360 μmol/L) reduces risk of fracture among people with gout. We emulated analyses of a hypothetical target trial using a "cloning, censoring, and weighting" approach to examine the association between lowering SU with ULT to the target levels and the risk of fracture using data from The Health Improvement Network, a United Kingdom primary care database. Individuals with gout who were 40 years or older and initiated ULT were included in the study. Among 28,554 people with gout, the 5-year risk of hip fracture was 0.5% for the "achieving the target SU level" arm and 0.8% for "not achieving the target SU level" arm, respectively. The risk difference and hazard ratio for "achieving the target SU level" arm was -0.3% (95% confidence interval [CI]: -0.5% to -0.1%) and 0.66 (95% CI: 0.46 to 0.93), respectively, compared with "not achieving the target SU level". Similar results were observed when the associations of lowering SU level with ULT to the target levels with the risk of composite fracture, major osteoporotic fracture, vertebral fracture, and non-vertebral fracture were assessed. In this population-based study, lowering the SU level with ULT to the guideline-based target level is associated with a lower risk of incident fracture in people with gout.

Numerical investigation of the Mode I/Mode II fracture behavior of the hybrid composite joints with a hybrid bondline

In this study, the fracture behavior of fracture characterization bonded joints consisting of hybrid composite adherends and hybrid bondlines under Mode I and Mode II loadings were investigated numerically. Numerical analysis was performed using LS-DYNA. Hybrid composite laminates (HCGFRE) obtained by sequencing plain woven glass fiber reinforced epoxy (GFRE) and plain woven carbon fiber reinforced laminates (CFRE) as adherends. Araldite AV138M and Araldite 2015 epoxy adhesives were also used to create the hybrid bondline. Mode I and mode II fracture behaviors were determined by numerical modeling of the Double Cantilever Beam (DCB) and End Notched Flexural (ENF) tests, respectively. In the numerical model, firstly, the fracture parameters of the relevant adhesives were found in the literature, and verification was made utilizing the numerical model. Then, the fracture behavior in both two modes was examined by forming a hybrid bondline. In the literature, there are restricted studies examining the fracture behavior of fracture characterization bonded joints with hybrid bondlines. Additionally, it is not encountered any study determining the both mode I and mode II fracture behavior of composite fracture characterization bonded joints with hybrid bondlines. Therefore, it is thought that this study will gain significant novelties to the existing literature.