Increase In Shear Strength Research Articles

The Effect of a Coating Sprayed Using Supersonic Flame Coating Technology on the Mechanical Properties and Interface Structure of a Thick Steel/Aluminum Composite Plate during Hot Rolling

Given the characteristics of a thick steel/aluminum composite plate, such as its large thickness and the significant differences between its components, it is difficult to prepare using direct rolling. Instead, a thick steel/coating/aluminum composite plate may be successfully prepared by combining supersonic flame coating technology with a hot rolling composite process. In this study, the interface shear strength test, SEM, EDS, and other detection methods were applied to investigate the effects of the reduction rate and coating thickness on the interface structure and mechanical properties. The results show that under the condition of single-pass direct rolling, the micro-interface of steel/aluminum is improved with an increase in the reduction rate, but the bonding strength of the interface remains poor. After adding the coating, the thickness of the diffusion layer and the shear strength increase significantly. When the coating thickness is reduced to 0.1 mm, the deformation coordination and shear strength of the composite plate are further enhanced under the combined action of mechanical interlocking and metallurgical bonding. The tensile shear fracture is mainly located at the steel/coating interface. The interfacial shear strength reaches 66 MPa, which exceeds the requirements of the US military standard MIL-J-24445A (SH) for steel/aluminum shear strength. The research results thus support the use of this new method for the simple and efficient production of thick steel/aluminum composite plates.

Refill friction stir spot welding tool plunge depth effects on shear, peel, and fatigue properties of Alclad coated AA7075 aluminum joints

This study investigates the impact of refill friction stir spot welding (RFSSW) on Alclad-coated AA7075 aluminum alloy, specifically exploring the effects of two plunge depths (g = 1.55 mm and g = 1.9 mm) on the mechanical and fatigue properties. The influence of the Alclad layer on the final joint properties is assessed. Internal flow analysis reveals a concentration of the Alclad layer at the corners of the stir zone for an increased plunge depth. Notably, the sample using a plunge depth of 1.55 mm exhibits a 32 % increase in pure shear strength compared to the sample executed with a plunge depth of 1.9 mm, emphasizing the significance of the plunge depth for achieving superior mechanical performance. SEM analysis of the fracture surface highlights deformation and dimples in the g = 1.55 mm sample, while EDS confirms the Alclad layer's presence, indicating its positive influence on mechanical resilience. Additionally, peel tests demonstrate a 41 % strength increase for the g = 1.9 mm sample. Low and high cycle fatigue tests reveal superior fatigue performance in the g = 1.55 mm sample, supported by SEM analysis illustrating crack initiation and fracture mechanisms. These findings contribute to a nuanced understanding of the interaction between plunge depth, Alclad ldistribution and resulting mechanical and fatigue properties.

LOAD VERSUS SETTLEMENT BEHAVIOR OF SOFT CLAY REINFORCED WITH CEMENT STABILIZED RECYCLED ASPHALT PAVEMENT-LATERITIC SOIL COLUMN

In this paper, the performance of cement stabilized recycled asphalt pavement (RAP)-Lateritic column inclusion in soft clay was investigated via a physical model. The load-settlement response and bearing capacity of the composite ground was studied at various cement contents (0%, 1% and 3%) and at 30% RAP replacement ratio. The soft clay was consolidated in the PVC mold in a diameter of 150 mm and 300 mm high while the stabilized RAP-lateritic soil column with a diameter of 50 mm was used as a column at the center of the soft clay. The results showed that the bearing capacity of the composite ground significantly increased with the increased shear strength of column. The purposed bearing capacity equation derived from the unconfined compressive strength of column and undrained shear strength of soft clay was found to predict the bearing capacity of the composite ground satisfactorily.

Compression and shear properties of OPC-MCA and basalt fiber cured shield waste mud after dry-wet cycles

The large-scale accumulation of shield waste mud (SWM) generated during urban subway construction is prone to cause potential environmental problems. A new low-carbon curing modified material, i.e., OPC-MCA, was firstly prepared to economically and environmentally treat SWM by partially replacing ordinary Portland cement (OPC) with a composite external admixture. Thereafter, laboratory curing experiments of SWM taken from the Jinan Jile Road Yellow River Tunnel were conducted by controlling OPC-MCA at a 20% dosage and basalt fiber (BF) at different dosages (0–1.05%). The appearance, mass and P-wave velocity of the cured specimens were characterized and the compression and shear strength tests were carried out. In addition, X-ray computed tomography (CT) and scanning electron microscope (SEM) analyses were performed to comprehensively assess the resistance of OPC-MCA cured SWM exposed to dry-wet (d-w) cycles with different BF dosages. The results confirmed that the optimal BF dosage for specimens that did not undergo d-w cycles was 0.45%, resulting in a 16.67% increase in compressive strength and a 51.56% increase in shear strength. The addition of BF enhanced the resistance of specimens to d-w cycles and reduced the deterioration rates of mass, P-wave velocity, and mechanical properties. The hydrophilic expansion property of clay minerals significantly contributed to strength degradation and pore deformation of cured SWM specimens. The development degree of microscopic cracks and pores in cured SWM specimens was significantly affected by both the dosage of BF and the number of d-w cycles. By incorporating BF, the volume and connectivity of cracks and pores were reduced, the formation of small-sized pores was decreased, and the expansion of cracks was inhibited throughout the cycling process.

Optimizing Lumber Densification for Mitigating Rolling Shear Failure in Cross-Laminated Timber (CLT)

Rolling shear in cross-laminated timber (CLT) has been identified as the governing factor influencing design value. Likewise, densification has been found to be an effective method of enhancing the rolling shear strength of lumber and in turn, CLT. In this study, utilizing knowledge of material properties, optimization of the compression ratio for densification has been presented. Three-layered CLT beams made from non-densified lumber, grade #1 loblolly pine (Pinus taeda L.), were subjected to a bending load at a span-to-depth ratio of eight and had a rolling shear failure at the mid-layer with a shear strength of 3 MPa. Assuming the same modulus of rupture (MOR) for both lumber and CLT made from the same species and grade, the MOR of lumber was used to calculate the minimum required shear strength (MRSS) of the transverse mid-layer to change the failure mode of the CLT beam from rolling shear to tensile failure. Using the relationship between the compression ratio and the increase in rolling shear strength, the optimized compression ratio for densification was calculated. This procedure resulted in a compression ratio of 16.67% for densification of the mid-layer to avoid rolling shear in the case of CLT beams with a span-to-depth ratio of eight. To verify this process, CLT beams with mid-layers densified at 16.67% were fabricated and submitted to a bending test. Rolling shear failure was mitigated and densified CLT beams failed in tension with a MOR similar to that of lumber, 47.45 MPa. Likewise, rolling shear strength was observed to increase by 48% for CLT that had a densified mid-layer at 16.67%.

Undrained shear strength of soft clay reinforced with encapsulated stone dust columns

PurposeThe stone dust column was used to strengthen the sample and had a significant effect on improving the shear strength of the kaolin clay. The application of stone columns, which can improve the overall carrying capacity of soft clay as well as lessen the settlement of buildings built on it, is among the most widespread ground improvement techniques throughout the globe. The performance of foundation beds is enhanced by their stiffness values and higher strength, which could withstand more of the load applied. Stone dust is a wonderful source containing micronutrients for soil, particularly those derived from basalt, volcanic rock, granite and other related rocks. The aim of this paper is to evaluate the properties of soft clay reinforced with encapsulated stone dust columns to remediate problematic soil and obtain a more affordable and environmentally friendly way than using other materials.Design/methodology/approachIn this study, the treated kaolin sample's shear strength was measured using the unconfined compression test (UCT). 28 batches of soil samples total, 12 batches of single stone dust columns measuring 10 mm in diameter and 12 batches of single stone dust columns measuring 16 mm in diameter. Four batches of control samples are also included. At heights of 60 mm, 80 mm and 100 mm, respectively, various stone dust column diameters were assessed. The real soil sample has a diameter of 50 mm and a height of 100 mm.FindingsTest results show when kaolin is implanted with a single encased stone dust column that has an area replacement ratio of 10.24% and penetration ratios of 0.6, 0.8 and 1.0, the shear strength increase is 51.75%, 74.5% and 49.20%. The equivalent shear strength increases are 48.50%, 68.50% and 43.50% for soft soil treated with a 12.00% area replacement ratio and 0.6, 0.8 and 1.0 penetration ratios.Originality/valueThis study shows a comparison of how sample types affect shear strength. Also, this article provides argumentation behind the variation of soil strength obtained from different test types and gives recommendations for appropriate test methods for soft soil.

Scalable electrochemical grafting of anthraquinone for fabrication of multifunctional carbon fibers

Carbon fiber electrodes were prepared by grafting anthraquinone molecules via a scalable electrochemical approach which simultaneously increased interfacial and electrochemical capacitance properties. In this work, anthraquinone diazonium salts were synthesized and grafted onto carbon fiber tows at various concentrations. These modified fibers were subsequently evaluated mechanically and electrochemically to analyze their suitability in structural supercapacitors. Compared to control fibers, the grafted anthraquinone groups resulted in a 30% increase in interfacial shear strength (IFSS) and 6.6× increase in specific capacitance. Industry application was also a focus thus carbon fibers were also modified with in-situ generated diazonium salts to determine the applicability to an in-line industrial process. Specifically, potentiostatic functionalization of fibers with in-situ generated diazonium salts AQ-1 and AQ-2, showed 3× and 4.3× increase in specific capacitance, respectively, relative to unmodified carbon fiber (CF). We expect that implementing a scalable method to introduce a conductive and electrochemically active covalently bound surface chemistry layer onto carbon fiber exhibits a higher specific capacitance than carbon fiber grafted with most other small molecules reported in literature. This will open new avenues for manufacturing multifunctional and high-performance fibers with tailored properties for specific/targeted applications.

Short beam shear performance of spread‐tow woven stitched composite with anti‐sandwich structure

AbstractSpread‐tow woven fabrics (STW) have attracted considerable attention because of their ultrathin structure and low porosity, which benefit the design and application of STW composites. Little is known about how the thickness relationship between the middle and surface layers affect the mechanical properties of sandwich structures. Therefore, this study developed an anti‐sandwich stitched composite with STW in the center and a nonwoven felt/STW hybrid on both sides. The interlayer shear behavior and damage mode transformation of STW composites with different middle‐layer thicknesses were studied using short‐beam shear tests, digital image correlation (DIC) full‐field strain nephograms and micro‐computed tomography (micro‐CT). The results showed that the anti‐sandwich structure improved the shear strength, particularly when the middle layer thickness was four times that of the surface layer. As the middle layer thickness ratio decreased, the synergistic effect of the anti‐sandwich structure was weakened, and the damage mode changed from ductile to brittle. Furthermore, the hybrid ratio of the STW/nonwoven fabric in the surface layer had little effect on the performance because of the good interfacial adhesion between the STW and nonwoven fabric. The anti‐sandwich structure that can improve the properties and stability of STW composites provides a reference for the structural design of STW composites in engineering applications.Highlights An anti‐sandwich composite was developed by spread tow woven fabrics. Nine types of anti‐sandwich composite were designed and fabricated. The thickness of the middle layer affected the synergistic mechanisms. The optimal anti‐sandwich structure has a 4.59% increase in shear strength. The specific shear strength is 14.86% higher over pure spread tow laminates.

Depriving friction stir weld defects in dissimilar aluminum lap joints

The contemporary automotive industry increasingly incorporates composite materials and innovative joining techniques to meet customer demands for lightweight, high-strength alloys. This research explores the feasibility of using friction stir welding (FSW) methods to fabricate dissimilar aluminum nanocomposite lap joints, integrating Al2O3 nanoparticles into the weld nugget. Lap joints were prepared with varying tool rotation speeds (1000–1600 rpm) and the mechanical and metallurgical behaviors of AA6061–AA7075-T6/Al2O3 lap joints were examined. The inclusion of filler material in the weld joint resulted in an 18% increase in shear strength compared to joints without filler. Dynamic crystallization impeded grain boundaries and reduced grain size in the weld stir zone (SZ), with the most enhanced mechanical characteristics observed at a tool rotation speed of 1400 rpm. The shear strength at 1400 rpm was 5780 N, representing a 17% increase compared to joints prepared at 1000 rpm. Field emission scanning electron microscopic examination revealed evenly dispersed Al2O3 nanoparticles within the weld zone, supporting the lap shear test results. Notably, joints created at lower (1000 rpm) and higher tool rotational speeds (1600 rpm) exhibited brittle fracture behavior. The addition of Al2O3 significantly improved lap joint tensile strength due to its uniform dispersion in the SZ. Increasing the FSW tool rotational speed from 1000 to 1400 rpm facilitated nanoparticle dispersion, further enhancing lap joint strength.

Improving the quality of resistance welded thermoplastic composite joints by applying ultrasonic

Resistance welding, a favored method for joining thermoplastic composites, often faces the challenge of nonuniform bonding which leads to weak bonding at the overlap edge and compromises joint integrity. This study proposes a novel modification to traditional resistance welding by incorporating ultrasonic during the final stage of the process. We employed various durations of resistance welding and ultrasonic to join the GF/PPS composites, which yielded significant improvements in bonding strength and welding efficiency. Applying ultrasonic introduced a self-adaptive temperature compensation mechanism, enhancing the temperature at the overlap edge while diminishing the temperature difference between the center and edge of the overlap. This method also improved fusion bonding by encouraging resin flow along the unfused interface at the overlap edge, thereby expanding the bonding area. Notably, the introduction of ultrasonic revealed a new bonding mechanism involving the interaction between molten PPS and unmelted PPS, which was thoroughly examined. The results revealed a 19% increase in lap shear strength and a 40% reduction in welding time for joints with ultrasonic compared to those without ultrasonic.

Tensile and Interfacial Mechanical Properties for Single Aramid III Fibers under Dynamic Loading.

In this study, the traditional mini split Hopkinson tension bar (SHTB) was enhanced for the dynamic mechanical performance testing of single fiber/resin interface of composites. Single Aramid III fibers were modified using a polyamine modification treatment. Quasi-static and dynamic tensile tests of modified single Aramid III fibers were conducted using an electronic tensile testing machine and mini SHTB. The test results indicated that the surface modification employing the Catechol-Tetraethylenepentamine (Cat-TEPA) approach had a negligible effect on the tensile mechanical properties of single Aramid III fibers. The microdroplet method was introduced to measure the dynamic interfacial shear strength (IFSS) of Aramid III fiber/waterborne polyurethane resin using a mini SHTB. The dynamic shear test results revealed an increase in the dynamic shear strength of the modified Aramid III fiber/resin interface from 36.16 MPa to 41.51 MPa. Furthermore, the Scanning Electron Microscope (SEM) photography of the modified single Aramid III fiber after debonding exhibited regular grid structures on the debonding area, which can prevent debonding between the single fiber and the microdroplet, thereby enhancing interfacial shear performance.

Improving mechanical behavior of adhesively bonded composite joints by incorporating reduced graphene oxide added polyamide 6,6 electrospun nanofibers

Adhesive joining of fiber-reinforced polymer (FRP) composites requires adequate interface tailoring and careful surface preparation to obtain a strong bond between components. This study aimed to improve the mechanical performance of adhesively bonded unidirectional carbon fiber-based (CFRP) composite parts by modifying joint surfaces with graphene-added electrospun Polyamide 6,6 (PA66) nanofibers. Reduced graphene oxide (rGO) was dispersed at 10 % wt/v PA66 solution at three different concentrations below rGO saturation limits. Bead-free nanofibers with homogenous graphene distribution were obtained on a prepreg by electrospinning. Addition of up to 2 % rGO yielded complete dispersion through the nanofiber network while the higher values created local agglomerations. Surface wetting experiments showed conversion of slightly hydrophobic surfaces to complete hydrophilic with electrospun nanofiber coating and the lowest contact angle was obtained at 2 % wt/v rGO addition (26.18°±2.03°). Composite plates were produced in a hot press keeping the modified prepregs on top. Plates with different surface treatments joined by secondary bonding using 3 plies of FM 300 K film adhesive. Mechanical properties of adhesively bonded composites were tested by Single lap joint and Charpy impact tests. We achieved an 18 % increase in shear strength and 31 % increase in impact strength by adding 2 % wt/v ratio rGO into PA66 electrospun nanofiber.

Plastic as a Soil Stabilizer

Soil stabilization is any process which improves the physical properties of soil, such as increasing shear strength, bearing capacity etc. which can be done by use of controlled compaction or addition of suitable admixtures like cement, lime and waste materials like fly ash, phosphogypsum etc. The cost of introducing these additives has also increased in recent years which opened the door widely for the development of other kinds of soil additives such as plastics, bamboo etc. This new technique of soil stabilization can be effectively used to meet the challenges of society, to reduce the quantities of waste, producing useful material from non-useful waste materials. Use of plastic products such as polythene bags, bottles etc. is increasing day by day leading to various environmental concerns.Therefore the disposal of the plastic wastes without causing any ecological hazards has become a real challenge. Thus using plastic bottles as a soil stabilizer is an economical utilization since there is scarcity of good quality soil for embankments. This project involves the detailed study on the possible use of waste plastic bottles for soil stabilization. The analysis was done by conducting plate load tests on soil reinforced with layers of plastic bottles filled with sand and bottles cut to halves placed at middle and one-third positions of tank.The comparison of test results showed that cut bottles placed at middle position were the most efficient in increasing strength of soil. The optimum percentage of plastic strips in soil was found out by California Bearing Ratio Test and using this percentage of plastic, plate load test was also performed. The size and content of strips of waste plastic bottles have significant effect on the enhancement of strength of the soil].

Theoretical Design of Strengthened Nanotwinned γ*-Boron.

The distinctive electron deficiency and unusual multicenter bonding situations of boron give rise to fascinating chemical complexity and imaginative structural polymorphism. Herein, we employ an independently developed method to construct the new twinned γ*-boron based on the well-known hardest elemental boron, γ-B28. Notably, the newly propounded γ*-boron phases exhibit considerably close energy levels with γ-B28 under ambient conditions. The simulated X-ray diffraction patterns of stable twinned structure present excellent agreement with experimental data. First-principles calculations reveal a 7.5% increase in the ideal Vickers shear strength of γ*-boron compared to γ-B28, attributed to diverse bond responses within the twinned slabs. The evaluated hardness of nanotwinned γ*-B reaches 59 GPa in consideration of the size hardening effect. Our research presents an efficient strategy for constructing new polymorphs of boron with improved mechanical properties and expands the knowledge about twinning structures of boron.

Comparing the Solderability of Different SA C0307 Composite Solder Pastes

In the present study, the effect of four oxide ceramics (TiO2, ZnO, ZrO2, and CuO) as reinforcements were investigated on the soldering parameters of the SAC 0307 solder alloy. The oxide ceramics were used in nano-powder format. Composite solder pastes were composed by the standard ball milling process of the nano-particles into the SAC 0307 solder paste in 0.25wt% weight fraction. The wettability, shear strength, and microstructure of the composite solder joints were studied and compared. The ceramic nano-particles did not have a major effect on the wettability of the solder. Shear strength increases were observed at the composite joints, except in the case of ZnO. Generally, Sn grain refinement was found in the Sn-matrix which could be the reason for the shear strength increase.

Achievement of high-strength Al/CFRP hybrid joint via high-speed friction stir lap joining and laser texturing pretreatment parameters variation

This paper presents the achievement of a high-strength Al/CFRP hybrid joint through a high-speed friction stir lap joining process, combined with variations in laser surface texturing pretreatment parameters. The study examined the impact of laser surface texturing parameters by varying the depth, interval distance and width of the laser texture. By adjusting laser texturing parameters, the softened PA66 was fully infused into the textured grooves on the aluminum surface, leading to a significant reduction in interfacial voids and cracks in Al/CFRP. The preliminary tensile shear test showed that the hybrid joint broke at the CFRP base material, indicating that the laser texturing exhibited excellent Al/CFRP interface strengthening ability. Further compression shear tests were applied to reveal the actual interfacial load-carrying performance for comparison. The maximum shear strength of 25.5−1.34+0.7 MPa was achieved at a joining speed of 3000 mm/min. Additionally, a mathematical model was proposed to assess the strengthening impact of laser texturing parameters, considering micro-texture geometry and interfacial defects. The tearing of PA66, detachment of carbon fibers, and the breakage of carbon fibers were the three primary types of fracture modes identified at the Al/CFRP interface. The joining mechanism revealed that both mechanical interlocking and the chemical bonding of Al-O-C contributed to the increase in joint shear strength. This study presents a credible method for producing high-strength Al/CFRP lightweight structures.

Effect of size factor and tapered angles on the shear behavior and strength of haunched beams reinforced with basalt fiber reinforced polymer rebars: Experimental and analytical study

Haunched beams are beams that exhibit varying effective depth over their span. This study includes an experimental and analytical analysis aimed at investigating the influence of size factor on the shear behavior of tapered beams reinforced with basalt fiber reinforced polymer BFRP bars. The main focus of this study revolves around investigating the effects of both inclination angle and size factor as key variables. In this study, a total of eight simply supported beams were tested. The beams were longitudinally reinforced with a 1% ratio of BFRP reinforcement, and separated into two equal groups. Each group consisted of one straight beam and three haunched beams. The haunched beams had varied tapering angles, namely 4⁰, 7.96⁰, and 11.86⁰. The first group is designated for the allocation of large beams, while the second group is designated for the allocation of small beams, which have a cross-section that is one-fourth the size of the large beams. The test results indicate that an increase in tapered angles leads to an increase in shear strength. Additionally, it was observed that smaller beams exhibited a greater normalized shear strength compared to larger beams with a significant rate as compared with straight beams. Subsequently, two equations were developed using the tested data, whereby one of them represents an optimal equation including a logical safety margin, while the other equation is characterized by a conservative equation, providing a substantial safety margin for predictions.

Enhancing the bond strength between glass fibre reinforced polyamide 6 and aluminium through μPlasma surface modification

Thermoplastic polymers generally exhibit relatively low surface energies and this often results in limited adhesion when bonded to other materials. Plasma surface modification offers the potential to functionalise the polymer surfaces, and thereby enhance the bond strength between dissimilar materials. In this study, glass fibre reinforced polyamide 6 (GFPA6) was modified using a novel μPlasma surface treatment technique and the effectiveness of the adhesive bond with aluminium was evaluated. The treated GFPA6 surfaces were characterised using atomic force microscopy (AFM), Raman spectroscopy, contact angle measurements, surface free energy calculations and wetting envelope analysis. The results show that there was a near exponential growth in root mean square roughness with increasing treatment scans. A significant increase in carbonyl and amide functionality on the polymer surface was observed using Raman spectroscopy. The total surface energy was found to increase from 42.2 mN/m to 67.6 mN/m following a single treatment scan. Significant increases in the tensile shear strength were observed up to 10 treatment scans, going from 1 kN to 2.3 kN, but no further increase was observed with additional treatment scans. These observations, coupled with the atmospheric nature of the technique, points to great potential as a rapid, on-line, and effective, polymer surface treatment technique.

Enhancing interfacial solvent resistance and mechanical properties of carbon fiber/polyether ether ketone composites with water‐borne sizing agents based on cross‐linkable polyphthalonitrile

AbstractThe inherent structural properties and elevated processing temperatures of thermoplastic resins present new challenges in the realm of carbon fiber (CF) sizing agents. Consequently, a water‐based cross‐linkable nitro‐phthalonitrile capped polyfluorenyl ether ketone sizing agent was meticulously designed. The sizing agent exhibits superior storage stability, encapsulating particles spanning dimensions from 66.51 to 87.71 nm. The inherent mechanism during the hot‐pressing stage involves a self‐crosslinking of nitrile groups toward stable structures with unparalleled resistance to solvents. The crosslinked sizing agent boasts a remarkable glass‐transition temperature of 290°C. Noteworthy, significance is the consequential 40.1% augmentation in maximum flexural strength, along with a commendable 35% increase in interlaminar shear strength for CF‐1.5/PEEK composites in contrast to their unsized CF/PEEK counterparts. In summary, the focal aspiration of this research endeavor lies in offering a straightforward and viable methodology for the exploration of cross‐linkable sizing agents, strategically catering to both “thermoplastic processing” and “thermosetting applications.”Highlights Bulky fluorenyl unit increases the intermolecular volume of copolymer poly(fluorenyl ether ketone). The introduction of the BPF unit to the molecular elevates the thermal stability of the copolymer. Unique electron‐donating proclivity of the fluorenyl group drastically improved its reactivity. The polymerization was accomplished at a relatively low temperature of 150°C for practical applications. The ILSS, IFSS, and bending strength were noteworthy increased by 35%, 74.02%, and 40.1%

Core-Shell Rubber Nanoparticle-Modified CFRP/Steel Ambient-Cured Adhesive Joints: Curing Kinetics and Mechanical Behavior.

Externally bonded wet-layup carbon fiber-reinforced polymer (CFRP) strengthening systems are extensively used in concrete structures but have not found widespread use in deficient steel structures. To address the challenges of the adhesive bonding of wet-layup CFRP to steel substrates, this study investigated the effect of core-shell rubber (CSR) nanoparticles on the curing kinetics, glass transition temperature (Tg) and mechanical properties of ambient-cured epoxy/CSR blends. The effects of silane coupling agent and CSR on the adhesive bond properties of CFRP/steel joints were also investigated. The results indicate that CSR nanoparticles have a mild catalytic effect on the curing kinetics of epoxy under ambient conditions. The effect of CSR on the Tg of epoxy was negligible. Epoxy adhesives modified with 5 to 20%wt. of CSR nanoparticles were characterized with improved ductility over brittle neat epoxy; however, the addition of CSR nanoparticles reduced tensile strength and modulus of the adhesives. An up to 250% increase in the single-lap shear strength of CFRP/steel joints was accomplished in CSR-modified joints over neat epoxy adhesive joints.