Double Shear Test Research Articles

Tailoring magnesium potassium phosphate cement-based adhesive for the improved bonding performance of CFRP/concrete interface

Magnesium potassium phosphate cement (MKPC) with rapid hardening and early high strength can be used as inorganic adhesive for externally bonded carbon fiber reinforced polymer (CFRP). This study aims to tailor MKPC as inorganic adhesive with good infiltration and bonding strength for CFRP-reinforced concrete. The influences of water-to-binder (w/b) ratios and particle sizes of potassium dihydrogen phosphate (PDP) on the fresh properties, hydration kinetics, pore structure, and strength development of MKPC were studied. The bonding strength of CFRP/concrete with MKPC-based adhesive was evaluated by double-shear tests. Results showed that a lower w/b ratio and a finer PDP enhanced the strength of MKPC due to a refined microstructure. The bonding strength of CFRP/concrete was dependent on the rheological characteristics and strength of MKPC. The use of a coarse PDP in MKPC was beneficial to enhance the bonding strength of CFRP/concrete. MKPC with coarse PDP and a w/b ratio of 0.2 resulted in the greatest bonding strength, corresponding to a 20% enhancement compared to epoxy resin. The superior bonding performance of MKPC was ascribed to its higher strength, a better infiltration for CFRP, and a larger MPC/concrete interfacial transition zone (ITZ).

Inter-laminar Strength of NITE-SiC/SiC Composites with Various Fiber Reinforcing Architecture

The mechanical performance of SiC/SiC composites is significantly influenced by the architecture of fiber reinforcement. Among the various fabrication methods, the nano-powder infiltration transition/eutectic (NITE) process is a promising technique that is capable of achieving a dense and stoichiometric SiC matrix. The reinforcement architecture, such as cross-ply (CP) or woven prepreg (WP), is determined during the preform stage of the NITE process, which is crucial in determining the mechanical properties of SiC/SiC composites. In this study, the tensile test and double notch shear (DNS) test were conducted using NITE-SiC/SiC composites to investigate the effect of the fiber reinforcing architecture on the fracture mechanism of SiC/SiC composites. The tensile strength and maximum shear strength of both CP and WP specimens were nearly identical. However, other mechanical properties, particularly those of CP specimens, exhibited significant variability. A comparison of fracture surfaces and load-displacement curve analyses from the DNS tests revealed that the cross points of the longitudinal or transverse fibers act as obstacles to both deformation and crack propagation. These obstacles were found to be more densely distributed in WP specimens than in CP specimens. The variability observed in the mechanical properties of CP specimens is likely due to size effects caused by the sparser distribution of these obstacles compared to the WP specimens.

Mechanical characterization and performance evaluation of twisted Jute-Kevlar hybrid composites with varied fiber orientations

Abstract Composite materials play a vital role in developing new materials in engineering and technology. Composites show how the properties of the matrix and reinforcement work together to create more robust, more rigid materials than would be possible from the individual components working alone. They consist of two or more component materials combined with notably dissimilar physical or chemical characteristics. Two categories of composite coupons have been developed in this research work: the first category (C1) is made up of jute twisted-Kevlar twisted jute fiber (0/90 degree), and the second category (C2) is made up of jute twisted-Kevlar twisted jute fiber (0/45 degree). The nano-silica is reinforced with the matrix with a weight percentage of 0%,5%,10% and 15%. The necessary interfacial adhesion and bonding between fiber layers have been accomplished using a 10:1 mixture of epoxy resin (LY556) and hardener (HY951). According to ASTM guidelines, the tensile, flexural, impact, double shear, wear, and hardness tests were carried out. This study uses two natural and synthetic fibers—twisted Jute and Kevlar fibers—as reinforcement. The Jute fibers have a high strength since they are high in cellulose. Efforts have been made to create a composite material with completely different twisted fiber orientations and to assess the mechanical properties of the composites. This involved various mechanical tests, analysis of wear surfaces, as well as DMA, DSC, FEA testing, and ultimately, the machining of the composites studied. The machining parameters used in waterjet machining have been carefully analyzed.

MICRO-MESO CHARACTERIZATION OF PREFABRICATED CONCRETE-CLT ADHESIVE JOINTS

This study evaluates the use of five commercially available epoxy adhesives (EAs), from low to high cost, as a connection alternative of timber-concrete composites (TCCs) using cross-laminated timber (CLT) and medium-strength precast concrete (25MPa). Five alternative EAs were initially evaluated via pull-off tests to determine the adhesive strength of the interface CLT/concrete, with average results varying from 0.6MPa to 3.6MPa. Subsequently, optical and scanning electron microscopy analyses were implemented to assess the microstructure of post-tested TCC specimens, finding that usually the CLT/concrete interface was not fully glued by the EAs and that there was a positive correlation between the penetration of each EA with the corresponding tension strength of the TCCs. Then, the three EAs with the largest adhesive strengths were further tested by small double-shear (SDS) tests evaluating their shear strength and deformation, as well as damage evolution and failure modes, which were obtained using digital image correlation. The SDS test average results ranged from 2.4MPa to 8.8MPa, and the EA with the best behavior was not the one with the highest tensile strength, but rather with the highest EA penetration into concrete, demonstrating that this property highly positively impacted the shear strength of TCCs. Finally, cost/benefit analyses were obtained, and interestingly, the EA with the best adhesive/shear performance was not the most expensive alternative, opening the discussion that, even though mostly expensive EAs have been used in TCCs, the option of technically valid and low-cost EA is feasible.

Heat treatment effects on the shear performance and microstructure evolution of W-core SiC fibers

SiC fiber reinforced titanium alloy matrix composites employed in elevated temperature aeroengine components are subjected to complex loading conditions. Investigating the shear performance of SiC fibers after heat treatment can help ensure the load-carrying capability of composites at service temperatures. This study presents a novel double shear testing method for W-core SiC fibers. The shear strength and stiffness of the SiC fibers in as-received and heat-treated conditions were measured. The morphologies of SiC fibers’ shear fracture surfaces and C coatings were thoroughly analyzed. The evolution of the internal microstructure and the composition of reaction layers after heat treatments were investigated. The shear strength of W-core SiC fibers at 95% survival probability reached 588.64MPa after 200 h of heat treatment at 600°Celsius, representing a 55% improvement over both the as-received and 1100°Celsius heat-treated conditions. After heat treatment at 1100°Celsius, the reaction layer between the W core and the SiC sheath thickened exponentially due to extensive elemental diffusion, resulting in the formation of numerous Kirkendall voids. The voids facilitated crack initiation and propagation, leading to a deterioration in fiber shear performance. The insights gained in this study regarding the shear properties of SiC fibers can provide support for predicting the mechanical performance of composites under complex loading conditions.

Shear behavior of BFRP anchor-jointed rock mass considering inclination angle and pre-tension

In this study, the double-shear tests of anchor-jointed rock mass were carried out to investigate the mechanical behaviors of Basalt Fiber Reinforced Polymer (BFRP) anchor bolt in the joint surface. A total of 21 specimens were prepared and two main influence factors were considered: the inclination angle of the BFRP anchor bolt (0°, 5°, 10°, 15°) and the load level of pre-tension (36, 72, 108 kN). The parametric study and design recommendations for the shear capacity of the joint surface under the BFRP anchor bolt were carried out. The results showed that a larger inclination angle or pre-tension force can improve the shear capacity and reduce the relative dislocation at the joint surface. When the inclination angle was 15°, the ultimate bearing capacity was increased by 51 % compared with that when the inclination angle was 0°. When the pre-tension force was 108 kN, the ultimate bearing capacity was increased by 142 % compared with that without pre-tension force. The analytical study found that Ranjbarnia's formulations were reliable to calculate of the shear capacity at the joint surface. The predicted results showed good agreement with the experimental results, with the relative errors less than 5 % for all groups. Then, by using this analytical model, the design parameters of the BFRP anchor bolt were tentatively determined at demanded shear capacities of 200 kN and 350 kN, respectively.

Mesoscale modeling of new-to-old concrete interface under combined shear and compressive loads

A mesoscale model of new-to-old concrete interface under combined shear and compressive loads is established, and a parameter study is conducted to evaluate the influence of interface roughness, bond strength, and fracture energy. The mesoscale model is numerically generated using a random aggregate technique, in which the number of aggregates is calculated using the Fuller grading curve and Walraven formula and the aggregates are randomly placed using the Monte Carlo simulation. The concrete damaged plasticity model is employed to simulate the mechanical behaviors of new and old mortars, as well as the interfacial transition zone between the mortar and aggregate. The linear elastic model is utilized to simulate the behavior of aggregates, while the cohesive-friction model is employed to represent the behavior of new-to-old concrete interface. The effect of interface roughness, bond strength, and fracture energy on the interface shear strength and post-peak shear strength using the double-shear test specimens is investigated. The results indicate that increasing the roughness of old concrete surface leads to significant increases in both the interface shear strength and post-peak shear strength, but the larger interface roughness is not necessarily better. As the interface bond strength increases, the interface shear strength remains the same, whereas the post-peak shear strength shows a large increase with the lower interface roughness. Moreover, the interface fracture energy imparts the minimal influence on the interface shear strength and post-peak shear strength, but the higher interface fracture energy can improve the overall constitutive behavior of new-to-old concrete interface if the roughness of old concrete surface is low. The numerical mesoscale model presented can provide the theoretical guidance and technical support for effective design and construction of new-to-old concrete interface and structures.

Experimental study and multi-objective optimization of the shear mechanical properties of recycled aggregate concrete with hybrid fibers and nano SiO2

Structural imperfections (microcracks, micropores, and weak interfacial transition zones) impact the shear mechanical properties of recycled aggregate concrete (RAC). Fibers and nanoparticles can mitigate these issues, enhancing the overall quality of recycled aggregates (RAs). Various hybrid systems, including basalt fiber (BF), polypropylene fiber (PPF), and nano-SiO2 (NS), were added to the RAC for double shear testing. Regression models were developed using the response surface method to optimize the hybrid systems. The study showed that the NS-BF-PPF hybrid system achieved the optimal shear strength, shear strain, shear toughness index, and shear fracture energy (6.99 MPa, 9.58 × 10−4, 0.716, and 34.603 J, respectively). These values were superior to those of the BF-PPF hybrid system and single system. The three-dimensional reticulated supporting structure devised by the BF-PPF effectively remedied the structural defects in the RA at various levels. Furthermore, the fibers integrated into the hybrid system act as bridges, absorbing shear energy during the pullout process. The incorporation of nanoscale NS stimulated the hydration response of the cement, resulting in a more compact pore structure within the RAC. Nonlinear multivariate regression models were fabricated utilizing the response surface method to maximize strength. The optimal contents of BF and PFF in the BF-PPF hybrid system were 0.344 % and 0.3 %, respectively. The optimal contents of NS, BF, and PPF in the NS-BF-PPF hybrid system were determined to be 3.5 %, 0.5 %, and 0.1 %, respectively. The combination of fibers and nanoparticles elicits a synergistic effect, significantly augmenting the shear performance of RAC.

Experimental analysis of the flexural behaviour of precast concrete composite beams with discontinuous connections

Full-depth precast deck panels hold the potential to enhance constructability and productivity, and reduce the costs associated with highway bridges. This paper investigates the influence of discontinuous shear connections between girders and panels on the flexural behaviour of composite beams. Experimental findings from precast composite beams and direct shear tests are presented, including L-shape push-off tests and double shear tests to determine resistance at rough concrete-to-concrete plain interfaces and shear pocket connections. Composite beams with a full-depth precast slab connected through a shear pocket with shear keys into the upper face of a precast beam exhibit equivalent flexural resistance to monolithic beams when shear pocket spacing remains below the effective depth of the composite beam. However, composite beams with shear pockets featuring plain interfaces show a reduction in flexural resistance of up to 30% compared to monolithic beams. Moreover, composite beams with shear keys demonstrate interface shear stiffness up to four times greater than those with plain interfaces, indicating full interaction. The paper proposes simplified equations to estimate flexural resistance for composite beams with full-depth precast slabs joined by shear pockets, showing a coefficient of variation of only 12% compared to experimental results, offering a reliable method for predicting flexural resistance in composite beams with discontinuous connections.

Study on numerical simulation and mechanical properties of anchor cable with C-shaped tube subjected to shearing

To examine the disparity in deformation behavior and mechanical qualities between anchor cables with C-shaped tubes and regular anchor cables under shear conditions. The double-sided shear tests of free-section anchor cables and anchor cables with C-shaped tubes were conducted utilizing the indoor large-scale double-shear test equipment with varying pretension loads. The indoor double-shear tests indicate that the inclusion of the C-shaped tube alters the stress distribution of the anchor cables inside the anchor cables with C-shaped tubes and mitigates the impact of stress concentration. Moreover, it facilitates the transition of the anchor cable's failure mode from a mix of tensile and shear breaking to mainly tensile breakage. In addition, ABAQUS finite element analysis software was used to establish a double shear test model of the anchor cable with C-shaped tube to accurately simulate the interaction and stress distribution among the anchor cable, C-shaped tube, and concrete block in the double shear test. The findings of the simulation results reveal that the numerical model can adequately depict the evolution of the stress distribution in the prestressed anchored structure and the damage of the concrete block with increasing shear displacement. The relational equation for the yield state of the anchor cable with C-shaped tube under combined tensile and shear loads is found by integrating the experimental and simulation data, the static beam theory, and the concept of minimal potential energy.

Characterization of intrinsic interfaces between fibre-reinforced composites and additively manufactured metal for designing hybrid structures

The combination of additively manufactured metal components with thermoset fibre-reinforced composites provides the possibility to produce hybrid structures with increased functionality and reduced mass. The application in the high-performance sector, for example the implementation of such a hybrid structure in electric drive units in aviation, provides the potential to achieve the high power densities required. The challenges in this regard are the manufacturing, design and dimensioning of the interface between the two components regarding the technical requirements, such as the high temperature range. In this publication, metal specimens are manufactured using selective laser melting (SLM) and then pre-treated. The joint with the composite is obtained in the subsequent infiltration process when the composite part is manufactured. For the experimental characterization of the interface different combinations of fibre-reinforced composites and metals are used. Within roughness measurement the surface of the different materials due to the treatment were analysed and the intrinsic interfaces were microscopically examined. The joint strength is investigated in double lap shear test at different temperatures and the results are discussed based on the fabrication process and the characteristics of the hybrid interface. The results provide the basis for the future design and numerical description of the interfaces.

Shear Performance of the Interface of Sandwich Specimens with Fabric-Reinforced Cementitious Matrix Vegetal Fabric Skins

The utilization of the vegetal fabric-reinforced cementitious matrix (FRCM) represents an innovative approach to composite materials, offering distinct sustainable advantages when compared to traditional steel-reinforced concrete and conventional FRCM composites employing synthetic fibers. This article introduces a design for sandwich solutions based on a core of extruded polystyrene and composite skins combining mortar as a matrix and diverse vegetal fabrics as fabrics such as hemp and sisal. The structural behavior of the resulting sandwich panel is predominantly driven by the interaction between materials (mortar and polyurethane) and the influence of shear connectors penetrating the insulation layer. This study encompasses an experimental campaign involving double-shear tests, accompanied by heuristic bond-slip models for the potential design of sandwich solutions. The analysis extends to the examination of various connector types, including hemp, sisal, and steel, and their impact on the shear performance of the sandwich specimens. The results obtained emphasize the competitiveness of vegetal fabrics in achieving an effective composite strength comparable to other synthetic fabrics like glass fiber. Nevertheless, this study reveals that the stiffness of steel connectors outperforms vegetal connectors, contributing to an enhanced improvement in both stiffness and shear strength of the sandwich solutions.

Strengthening Device for Improving Shear Performance of Anchor Cable in Rock Support.

Many designs of anchor cables are currently in use for rock support in civil and mining operations. Because of the exposed surface and weak shear performance of the cable bolt's free section (CBFS) in end-anchored structures, breaking failure frequently occurs. Numerical simulations and laboratory experiments were performed in this study to develop measures to improve CBFS resistance to shear failure. Analysis of shear characteristics of the CBFS showed that higher axial tension weakens the cable bolt's shear resistance, and that shear damage on the cable surface and uneven distribution of shear stress aggravate CBFS tensile-shear failure. A high-strength steel pipe is proposed to protect the shear cable bolt, and the preliminary design of a CBFS-strengthening device (CFSD) is presented. Numerical simulation revealed that the CFSD effectively improved CBFS shear resistance and provided protection from harmful shear damage. The optimal performance of a Q-type (slotted steel pipe) CFSD was confirmed. The mechanism of improvement of the cable's shear resistance to surrounding rock by employing the CFSD was analyzed. Double-shear tests were carried out on a bare cable bolt and a cable bolt with a Q-CFSD. The results revealed that the CFSD increased the peak shear force on the joint plane, cable peak axial force, and ultimate shear displacement by 31%, 18%, and 11%, respectively. The proposed device is effective in improving the shear performance of end-anchored cable bolts and enhancing surrounding rock stability.

Enhancing the fracture toughness of laminated composites through loop warp yarns

The delamination tendency is a key factor affecting the practical use of laminated composites. How to improve the interlaminar strength and interlaminar fracture toughness of laminated composite is a focus of research on composite materials. A three-dimensional (3D) weaving technique is employed to weave loop warp yarns (loops) with 3D fiber bundles instead of warp yarns on the basis of plain fabrics. The contribution of loops to the interlayer performance is revealed by double cantilever beam (DCB) tests, end-notch flexure (ENF) tests, flexural tests, and double notch shear (DNS) tests. Test results show that the mode I and mode II interlaminar fracture toughness values of the single-sided-loop two-dimensional (2D) woven laminated composite (SWLC) are 77% and 58.2% higher than the interlaminar fracture toughness values of the general 2D woven laminated composite (GWLC). As companied with the ones of GWLC, flexural strength and modulus of SWLC increase by 73% and 69.1%, and the interlaminar shear strength of SWLC increases by 45.7%. The loop yarns act as a link between the interlaminar matrix and the reinforcing fiber fabric and thus improve the poor interlaminar performance of GWLC. The reported information may provide a reference for the application of the SWLC in practice.

Experimental and numerical evaluation of hydro-thermal ageing's effects on adhesive connections in offshore structures

In offshore structures, the need to replace or strengthen existing metal components arises over time. One possible solution is the use of bonded connections. Nevertheless, the durability of the adhesive connections is highly compromised by the prolonged contact with water.In this paper, an experimental and numerical evaluation of hydro-thermal ageing's effects on polyurethane adhesive connections has been analysed. An efficient semi-analytical procedure is developed for the design or verification of existing structures reinforced by bonded steel elements. The model can evaluate the interfacial shear stress at all loading stages up to the failure of bonded joints exposed to the marine environment. The model is based on Bernoulli beam theory and satisfies the requirements of equilibrium and strain compatibility, allowing for interfacial deformations.Furthermore, the mechanical behaviour of bonded connections subject to accelerated ageing has been experimentally investigated. More in detail, an experimental program including double lap shear and end-notch flexure tests was performed to evaluate the cohesive behaviour in Mode II of a polyurethane structural adhesive under the combined effects of water and temperature during 150 days of exposure. The experimental and numerical investigation shows how the performance of the adhesive joints is influenced by the ageing conditions.

Investigation of the behaviour of adhesively bonded joints between timber and self-compacting concrete

Composite constructions made of wood and concrete are being researched as revolutionary structural components that offer many benefits. The connection in timber-concrete-composite (TCC) is typically made via mechanical means. This study describes the TCC bonded by adhesives, particularly the mechanical behaviour of the joints between timber (GL24h) and self-compacting concrete (SCC) set by the dry or wet bonding process. For this purpose, double push-out shear tests on TCC joints bonded by epoxy resin of adhesives were performed. The role of several variables was considered for both fabrication processes. These parameters were: variation of moisture content (m.c.) of timber, adhesive type, adhesive thickness, sand addition, concrete surface treatment, and scale of bonding length. The results showed that glueing seems to be a feasible alternative instead of mechanical means for producing dry and wet TCC joints. Under dry conditions of timber elements, the shear strength can be considered highly satisfactory, with a mean value range of 6–8 MPa. The failure mode is primarily affected by concrete and timber failure. However, the findings of this study confirm the hypothesis that increasing the moisture content of timber before the gluing process significantly reduces the shear strength of adhesively bonded TCC joints by approximately 30% in certain instances. These results contribute to understanding the challenges and limitations of the bonding system, providing valuable insights for optimizing the design and manufacturing of timber-concrete composites.

Orientation-dependent extreme shear strain in single-crystalline silicon - from elasticity to fracture

Measuring strain accurately at small length scales poses a significant challenge, making it difficult to obtain precise elastic properties of small materials. This becomes particularly pronounced for test geometries beyond micro-pillars and for materials with high elastic limits and high Peierls stresses. This study investigates the elastic strain limits and strain distribution in micro double shear tests conducted on single-crystalline silicon with different crystallographic orientations. In situ scanning electron microscopy images were used to obtain full-field strain maps using digital image correlation. This local strain analysis approach revealed that the shear zones of the test geometry are not solely under pure shear conditions, but also experience superimposed bending. The local strain analysis approach increases the precision of measured elastic properties to ±15% of the literature value compared to deviations of 75-80% using the traditional global strain analysis approach. This study highlights the limitations of the global strain analysis approach in complex specimen geometries and demonstrates the effectiveness of digital image correlation in accurately determining elastic strain at the small length scale. Furthermore, both the low defect density in the samples as well as the small length scales allow for the exploration of orientation dependent strength levels close to the theoretical limit.

Mechanical and dynamic mechanical properties of hybrid kevlar/natural fiber composites

The current experiment aimed to identify the characteristics of composite materials enhanced with aloe vera, bamboo, palm, and kevlar fibres. Three different types of combinational fabrication—Type I (a blend of aloe vera and bamboo), Type II (a combination of bamboo and palm), and Type III—were carried out from all the other them (blend of palm and aloe vera). Analysis was done on the mechanical and dynamic-mechanical evaluation of biocomposites made spontaneously. Natural fibres used to produce hybrid composites were alkaline and treated in a 2.5 ml NaOH solution for 6 h at room temperature to get acceptable characteristics, then dried to remove the wax and oils on the natural fibre’s exterior surface. The effect of different stacking sequences on the mechanical and dynamic properties of manufactured composites has been investigated experimentally through ASTM standards. Impact, inter-delamination and double-shear tests are used to evaluate the mechanical properties; the failure mechanisms of the fabricated hybrid composites with various stacking sequences and testing conditions were investigated through the fractographs of SEM analysis. Type I S1 samples were found to display significant impact energy (10 Joules) as compared to other samples, and the break load of composite specimens was higher at 4.5 KN in S2 samples of type-III as compared to type-I and II, revealed Type-I samples with significant peak area of 0.492 delivered at 102.01 °C as compared to two types, Type-3 (Palmyra Palm + Aloe Vera) composite gave the best mechanical, dynamic properties.

A Study of Anchor Cable and C-Shaped Tube Support for the Roadway of Shuangliu Coal Mine

Active support using highly prestressed cable bolts and anchor cables has become a mainstream support technology for coal mine roadways. However, the ability of bolts and anchor cables to withstand transverse shear decreases with the prestress level, jeopardizing mining safety. This study proposed a technical solution to this problem featuring anchor cables enclosed in an axisymmetrical tube with a C-shaped cross-section (ACC), which are highly prestressed and can withstand high transverse shear. The ACC mechanical performance was tested in the #318 gas extraction roadway of the Shuangliu Coal Mine, China, characterized by extensive deformation under original support conditions. Theoretical analysis, laboratory tests, numerical simulation, and field tests were performed to analyze the shear mechanical properties of the ACC and anchor cables alone. The double shear test results revealed that the proposed ACC scheme increased the transverse shear resistance and stiffness by 10–25% and 20–40%, respectively. The FLAC3D numerical simulation showed that the roof-and-floor and rib-to-rib convergences decreased by 9.53 and 25.11%, respectively. The area of the stress concentration zone also decreased. Field monitoring showed that the ACC achieved good support performance. During the monitoring period, the maximum roof-and-floor and rib-to-rib displacements were 40 and 49 mm, respectively. The ACC scheme offered adequate shear resistance and effectively controlled surrounding rock deformation in the gas extraction roadway under study, making it applicable to similar engineering scenarios.

Calibration of ductile and shear damage models for carbon and stainless steel shear studs

AbstractSteel‐concrete composite beams are commonly used in bridge construction. The corrosion of the supporting steel beams and the shear connectors are however known as a major cause of premature deterioration of composite bridges. Stainless steel beams and shear connectors offer a viable alternative solution to the steel corrosion problem in composite bridges located in harsh environmental conditions. This paper presents experimental and numerical investigations of the tensile and shear behaviour of stainless steel welded shear connectors. The results of tensile coupon and double shear tests on stainless steel and carbon steel shear connectors to characterise the tensile and shear response are reported. Numerical modelling is carried out using the ABAQUS finite element software to develop calibrated ductile damage and shear damage fracture models for stainless steel shear connectors. The development and validation of the numerical models together with the calibration of the fracture models are presented and comparisons are made with those of carbon steel shear connectors.