Load-displacement Hysteresis Curves Research Articles

Study on hysteresis performance of four-limb CFST latticed column-box girder joints based on GA-BP neural network

This study investigates the seismic performance and energy dissipation capacity of the concrete-filled steel tube (CFST) latticed column-box girder joints. A low-cycle reciprocating load test was carried out on the CFST latticed column-box girder joints with three different connection forms. Based on the test results, a genetic algorithm (GA) is developed in combination with the back propagation neural network (BPNN) model for prediction research. Using a training set of joints with single-limb diagonal and cross-diagonal braces (training set), the development of load-displacement hysteresis curves of joints with transverse diaphragm plate (test set) under low-cycle reciprocating loads is predicted. The test results are compared with those obtained from the traditional algorithms and finite element simulations. The results on the joint hysteresis performance show that all three types of joints have a good seismic performance and energy dissipation capacity. Compared with the traditional algorithms, the GA-BP model predicts more accurate results and is therefore used to predict the load-displacement hysteresis curves of CFST latticed column-box girder joints, which is shown to be convenient and feasible.

Seismic performance evaluation and numerical analysis of CFDST long columns with local corrosion under eccentric compression

In this study, the seismic performance of locally corroded CST and CFDST long columns was evaluated by quasi-static tests. The effects of four levels of corrosion and two types of cross-sections on damage patterns, horizontal load-displacement curves, and seismic indexes were assessed. ABAQUS software was used to conduct extended simulations on long columns of CFDST, analyzing the impact of each parameter on seismic performance. Experimental results indicated that the horizontal load-displacement hysteresis curves of the CFDST long columns within the specified corrosion parameters exhibit robust characteristics, demonstrating improved seismic performance and energy dissipation capacity while preventing sudden damage due to local buckling. The parametric analysis showed that increasing the diameter-to-thickness ratio of the outer steel pipe and decreasing the hollow ratio significantly impact the peak load, whereas increasing the axial compression ratio and eccentricity results in non-uniform specimen damage and reduced peak load.

Coupled behavior and seismic performance assessment of square-over-round RCFDST column with reinforced ribs to steel beam joints under cyclic loading

The cyclic loading test study and finite element analysis (FEA) were conducted to investigate the seismic performance of five square-over-round recycled concrete-filled double skin steel tubular (RCFDST) columns with reinforced ribs to steel beam joints varying parameters such as the length of ribs, hollow ratio, axial compression ratio, the ratio of beam-column flexural linear stiffness and strength of the recycled concrete. It was found that a larger the displacement resulted in a lower the strength degradation. Moreover, the structures with two types of concrete showed similarities in strength degradation. In the experiment, compared to the cases without reinforced ribs, the specimens with reinforced ribs exhibited a larger value of stiffness and related rigidity degeneration primarily, and then showed a slow trend in rigidity degeneration laterally. The ductility of the cases with recycled concrete is twice that of the cases with normal concrete. In addition, the FEA model with optimal β of 0.5 agreed with the experimental results in both their damage patterns and horizontal load-displacement hysteresis curves. According the ratio of performance to cost, the optimal ratio of beam-column flexural line stiffness (km) is found in a range from 1.0 to 1.5. In a whole, the joints with reinforced ribs show generally excellent seismic performance.

Vision-oriented machine learning-assisted seismic energy dissipation estimation for damaged RC beam-column connections

After a seismic event, damage quantification is necessary for safety evaluation, collapse proximity judgment, and measurement of the residual seismic capacity of the joints. Machine learning-based predictive models are developed in this paper aimed at the non-destructive and non-contact estimation of energy dissipation ratio for seismically damaged beam-column joints through surface crack texture complexity indices. For this purpose, the authors collected an experimental dataset comprising 934 images of cracked and/or crushed reinforced concrete-framed joints from 254 specimens under cyclic loading. The associated energy dissipation ratios are then extracted from the lateral load-displacement hysteresis curves for each image by the authors, along with the image-derived fractal indices. Machine learning models with six algorithms, including Linear Regression, Multi-Layer Perceptron, Decision Tree, Random Forest, Gradient Boost, and CatBoost, are trained by 80% of images as a training dataset and validated through the remaining 20% of images in two scenarios. The first scenario develops models by component geometric dimensions and generalized fractal indices calculated for the beams, columns, and joints of seismically damaged connections, while the second scenario adds structural parameters to visual indices to estimate the energy dissipation ratio as the target parameter. Performance evaluation of trained models in the mentioned scenarios via common correlation and accuracy measures, along with the k-fold cross-validation method, indicated that CatBoost-based ML models in both scenarios provide optimal results with R2 = 0.89, RMSE = 0.10 for scenario I and R2 = 0.92, RMSE = 0.09 for scenario II using testing dataset. The first scenario based on the CatBoost algorithm with the R2 variation range of 0.07 and RMSE variation range of 0.03 across the test folds provides a sufficient performance in terms of generalizability and accuracy for estimating the energy dissipation ratio through lower number of input variables.

Lateral performance of cold-formed steel framed shear walls using slitted sheathing with stiffeners

Cold-formed steel (CFS) framed shear walls with steel sheathing are promising lateral-force-resisting members of mid-rise buildings in seismic regions. Previous studies have demonstrated that steel sheathed CFS framed shear walls have high shear capacity but some shortcomings, such as the low ductility caused by the premature damage of the frame and the shear buckling of the sheathing. This paper presents an experimental study on a novel type of CFS framed shear wall with slitted steel sheathing (CFS-SSWs), which uses longitudinal slits to change the failure mode of the sheathing so that the ductility of the wall can be improved; Meanwhile, stiffeners are utilized to enhance the out-of-plane stability of the slitted sheathing and the integrity of the wall. Six full-scale CFS-SSW specimens were tested under monotonic and cyclic lateral loading. Three types of stiffening approaches (Type I, Type II and Type III) were adopted for the walls. Test results were analysed to investigate lateral performances of walls under different stiffener arrangements, including failure modes, load-displacement hysteresis curves, backbone curves, stiffness and strength degradation, and energy dissipation capacity. The measured strengths of the walls in the tests were assessed using theoretical indexes. It is found that peak loads and energy dissipation capacity of stiffened walls are noticeably higher than those of the unstiffened wall. Type II and Type III are effective stiffening approaches that could mitigate the buckling of the slitted sheathing and enable the links between the slits to reach the full plastic strength. By connecting the stiffeners and studs through stiffener connectors, Type III has the most significant enhancement on the stiffness, strength and ductility of the wall.

Experimental and numerical investigation on strengthening mechanism of rib-reinforced round-over-round RCFDST column jointed with steel beam under cyclic loading

This paper involved both experimental and numerical investigations on the behaviour of twelve types of recycled-concrete filled double-skin steel tubular (RCFDST) structures subjected to the cyclic loading with reinforced ribs at the column–steel beam joints, of which the damage pattern and seismic performance were analysed by varying the ratio of beam–column flexural linear stiffness, axial compression ratio, hollow ratio, type and strength of the concrete, and the length of ribs. The results indicate that the specimens primarily exhibited the damage pattern of the plastic hinge at both ends of the beams, and that the horizontal load–displacement hysteresis curves with full loop at the top of the column were observed. Moreover, the structures composed of recycled concrete from 40 MPa to 60 MPa presented no reduction in ultimate load as well as the joint ductility to those of the ones with normal concrete. Regarding the performance of RCFDST, the optimal ratio of beam–column flexural line stiffness (ki) is found in the range of 1.0 to 1.5. This study demonstrated that the recycled concrete made from the industrialized aggregate formed by crushing waste concrete from road bases has potential application prospects in Concrete-filled double skin steel tubular (CFDST) structures due to its low cost and good seismic performance, including high ultimate load capacity and low energy consumption.

The Performance of Concentrically Braced Frames (CBF) in Chevron V Brace and Diagonal Configuration by Considering Various Frame Heights

Concentrically Braced Frame (CBF) is a structural system with high stiffness, so it is recommended to be implemented in earthquake-hazard areas. The stiffness in CBF is contributed by its diagonal component, which is called bracing. Bracing reduces lateral deformation on the frame system because of the earthquake and prevents heavy damage or failure of the structure. So far, several studies have been conducted. However, the effect of the frame height and the bracing configuration on the CBF performance has not yet been clarified. This study analytically investigated several models of CBF in Chevron V Brace and Diagonal configurations. Those models were prepared with different frame heights. The analyses were conducted by employing the cyclic load and considering yield displacement control in each model. The observation was emphasized on the load-displacement hysteresis curve, from which the performance of each model can be revealed. Three parameters of performance are evaluated: strength, stiffness, and dissipation energy. The analysis discovered that the Diagonal CBF performed better than the Chevron V Brace CBF by presenting a larger and more stable hysteresis curve, which is addressed to better energy dissipation. It is also discovered that reducing the frame height is suggested to enhance the CBF performance due to the earthquake

Shear capacity estimation of core steel tube reinforced PCCC column-beam interior joint under quasi-static load

In this study, the quasi-static tests were conducted on 13 core steel tube (CST) reinforced PVC-CFRP confined concrete (PCCC) column-beam interior joints. Distinct shear failure occurred in all joint specimens. The load-displacement hysteresis curves appeared pinching phenomenon, and the shape of hysteresis loops gradually deformed from shuttle to arch and finally changed to reverse S shape. The overall shape of hysteresis curves were relatively full, demonstrating that the joints had favorable seismic performances and energy dissipation capacity. The strain development law of materials in the joint area in the process of stress was clarified. The increment of joint stirrup ratio ([Formula: see text]), axial compression ratio ([Formula: see text]), column reinforcement ratio ([Formula: see text]) or beam reinforcement ratio ([Formula: see text]) improved the calculated shear capacity of the joints. The calculated shear capacity increased first and then decreased slightly as the diameter-thickness ratio of CST ([Formula: see text]) increased. In comparison, spacing of CFRP strip had little impact on the calculated shear capacity. Additionally, the concrete strength enhancement coefficient ([Formula: see text]) and joint stirrup utilization coefficient ([Formula: see text]) were introduced respectively to modify the shear capacity of concrete and joint stirrups, and a simplified formula for predicting the shear capacity of CST reinforced PCCC column-beam interior joints under quasi-static load was proposed. The predicted results agreed well with the test data.

The mechanical performance evaluation of recombinant bamboo with weakened metal connections under low-cyclic loading

ABSTRACT Tearing failures often occur at the bolt position of the recombinant bamboo beam under a large bending moment and shear force due to its poor compressive strength perpendicular to the grain. In this study, three H-shaped weakened connections were designed to explore the mechanical performance of the recombinant bamboo frames under low cyclic loading. The weakened forms of the web were selected as variables, including elliptical, rhombic, and arc holes. Load-displacement hysteresis curves, skeleton curves, stiffness degradation, ductility analysis, equivalent viscosity damping coefficient, and failure modes of the recombinant bamboo frame with three weakened connections were compared and analyzed. The results show that the weakened connections achieved the purpose of the outward movement of the plastic hinge. The moment and shear force will lead to the stress concentration of connection with the rhombic hole, and buckling failure of connection with the arc hole is easy to occur. Comparatively, the ultimate bearing capacity and energy-dissipating capacity of connection with the elliptical hole are the best among the three weakened connections. In conclusion, the weakened shape and position have a great influence on seismic performance.

Investigation of the seismic performance of CRTS III slab ballastless track of high-speed railway under low-cycle reciprocating load

In the China Railway Track System (CRTS) III slab ballastless track (SBT) system, the self-compacting concrete filling layer (SCCFL) and the base slab are connected via a rubber pad, geotextile, convex platform, and groove. This is a complex interaction between the SCCFL and base slab. As a buffer member between SCCFL and base slab, the rubber pad significantly impacts the seismic performance of CRTS III SBT. To explore the failure mode and seismic performance of CRTS III SBT, four CRTS III SBT specimens with different rubber pad thicknesses were designed and subjected to low-cycle reciprocating load tests in this study. The characteristics of the load-displacement hysteresis curve and load-displacement skeleton curve of CRTS III SBT specimens were then analysed. The failure mode, energy-dissipation capacity, ductility, stiffness degradation of CRTS III SBT specimens, and the influence of rubber pad thickness on the seismic performance of CRTS III SBT specimens were studied. It was found that when the low-cycle reciprocating loading was applied on the CRTS III SBT specimens, the interlayer bonding between the SCCFL and the base slab was the first to fail, followed by compressive deformation of the rubber pad. The concrete at the convex platform-SCCFL interface cracked, and the concrete in the four corners of the groove cracked until failure. When the rubber pad thickness was increased, the ultimate bearing capacity of the CRTS III SBT specimens under low-cycle reciprocating loads remained constant. However, the corresponding energy-dissipating capacity, ductility, and seismic performance all improved.

Hysteresis behavior of 3D RC exterior beam-column joints strengthened with CFRP sheets and spike anchors

Full-scale 3D exterior beam-column joints lacking shear reinforcement but externally shear-strengthened with carbon fiber reinforced polymer (CFRP) sheets were investigated with respect to their behavior under both gravity and lateral cyclic loadings. For this purpose, three such joints including one control and two experimental ones (strengthened either with CFRP sheets or with both CFRP sheets and spike anchors) were subjected to relevant tests. Prior to CFRP installation, all the externally strengthened specimens were subjected to surface preparation and grooving in order to prevent possible CFRP debonding. The flexural capacity of both the non-strengthened and strengthened joints were estimated using a specially-developed analytical method. Comparisons of the lateral load–displacement hysteresis curves and in the test results revealed that, compared to the control, the externally strengthened joints showed enhancements of 30, 222, and 200% in lateral load-bearing capacity, energy dissipation, and secant stiffness, respectively. It was further found that despite the efficacy of the shear retrofit design proposed for 3D exterior connections, those strengthened with the combined CFRP sheets and spike anchors outperformed the ones solely strengthened with CFRP sheets. The sectional analysis results also revealed that the simple method proposed in this study is well capable of estimating bearing capacity in both the control and strengthened connections with reasonable accuracy.

Seismic Behaviour of Hybrid Precast Shear Walls with Partially Connected Vertically Distributed Reinforcements

This paper presents a joint mode for a vertical grouting sleeve and a partially distributed reinforced composite connection. The seismic performance of four hybrids precast shear walls with a shear span ratio of 1.83, an axial compression ratio of 0.20, and partially connected vertically distributed rebar was studied by pseudo‐static tests. The connection ratios of the reinforced concrete with a vertical distribution were 100%, 67%, 50%, and 33% and were compared with cast‐in‐place shear walls. It was found that both the precast and cast‐in‐place specimens demonstrated bending and shear failure modes. Both ends of the mortar layer were cracked under compression, and steel connection failure occurred under the ultimate load. The load‐displacement hysteresis curve was bow‐shaped and relatively full; the yield load increased from 11.4 to 16.6, and the peak load increased from 4.2 to 6.8 compared with those of the cast‐in‐situ specimen. The strength degradation performance of the precast specimen was slightly weaker than that of the cast‐in‐place specimen. The ductility coefficient of the precast specimens was approximately 4, and the ultimate displacement angle was between 1/30 and 1/32, which was larger than the limit value of elastic‐plastic interlayer displacement of shear wall structures required by the code. The reduction in the number of vertically distributed rebar connections led to a decrease in the bearing capacity, stiffness, ductility, and energy dissipation, but the impact was very small.

Experimental study on the seismic performance of steel–concrete beam–column connections for prefabricated concrete frames

A novel type of prefabricated steel–concrete beam–column connection with different configurations for moment-resisting frames was developed for better constructability . Five beam–column connections, four prefabricated steel–concrete specimens, and one reference monolithic joint were tested under reversed cyclic load–displacement controlled conditions. The main variables were the steel form in beams and columns, fabrication method , and use of steel fiber reinforced concrete (SFRC) in the joint and connection parts. The cracking patterns and load–displacement hysteresis curves were recorded during the test. The efficiency of the developed connection was compared based on bearing capacity, energy dissipation , ductility, and stiffness. The results revealed that the prefabricated specimens with welded reinforcement connection exhibited flexural failure at the prefabricated beam, whereas the specimens with bolted end plates or weld-bolted H-steel beam connecting method failed through joint shear failure. The proposed prefabricated H-steel concrete connection with bolted end plates and SFRC had higher strengths and stiffnesses, more stable load–displacement cycles, and better energy dissipation capabilities. Moreover, the concrete spalling in the joint was adequately controlled, and shear deformation was also reduced. The H-steel beam connector in the proposed connection could effectively transfer loads under earthquakes. • A new prefabricated concrete beam–column connection connected with variable steel configurations is developed. • Cyclic loading tests performed on four prefabricated connections and one monolithic connection. • The prefabricated connection with welded reinforcements to H–steel flange fails in flexural failure. • Connections with bolted end plates or weld-bolted H-steel connection shows shear failure. • The prefabricated connections demonstrate satisfactory strength, stiffness and energy dissipation capacity.

Experiments on the seismic performance of Y-shape joints of subway stations built by enlarging two parallel shield tunnels

To improve the seismic performance of subway stations built by enlarging two parallel shield tunnels, joints of special structures between prefabricated open-loop segments and cast-in-site main station structures were proposed. Experiments on the low-frequency cyclic loading of full-scale models of joints under different structural configurations werecarriedout. The seismic performance, such as the load–displacement hysteresis curves, skeleton curves, structural ductility, strength degradation, energy dissipation, strain of the cable-stayed bars and failure modes, were studied. The results showed that compared with the pre-embedded connector joint, the pre-embedded steel plate joint had advantages in terms of the mechanical stability, intensity, stiffness, energy dissipation capacity and ductility performance. However, the relative displacement between the segment and wall column of the pre-embedded steel plate joint was larger than that of the pre-embedded connector joint. Both types of joints had a full hysteretic circle, good ductility nature, energy dissipation ability, and stable elastic and elastic–plastic deformation. The cable-stayed bars did not yield in the stretch area when the joints failed. Both of the joints could meet the performance requirements of strong joints and weak components.

Experimental study on mechanical properties of the steel friction pads used in a rotational friction damper

The optimal friction interface offered by friction pads should have stable frictional energy consumption performance, be easily fabricated, and satisfy the structure durability requirements imposed by use in civil engineering operations. In this paper, firstly, to assess the friction performance of the friction pads, a new clamping set-up equipped with a high-strength bolt was proposed for use as a friction-damping device. Then an experimental study was conducted with the clamping set-up on six different types of friction pad specimens. The main parameters are the mechanical properties, the friction interface area, the superficial treatment method applied to the steel friction pads, and the loading protocol. The experimental results indicate that: the load–displacement hysteresis curves are stable and exhibit no degradation in behaviour throughout the test, suggesting that the energy absorption performance of the friction damper is significant; the friction damper exhibit significant initial stiffness, showing that the rotational friction damper can provide stiffness for frame structures before rotation; the coefficient of friction of the friction pads is found to be influenced by the mechanical properties; in addition, the load–displacement hysteresis curve in the second loading stage is more stable than that in the first loading stage.

Seismic performance of a square HSS column to H-section beam bolted connection with double cover plate

This study presents six pseudostatic tests on square hollow section steel (HSS) column to H-section beam bolted connections with double cover plates. The failure modes, load–displacement hysteresis curves, and backbone curves of the joints were obtained, as were the energy-dissipating capacity, stiffness, and strength. The seismic energy of the connections is dissipated by slip between the contact surfaces and plastic deformation of the beam, clamp plates and bolt holes. The joints have good rotation capacity, energy-dissipation capacity, and reasonable strength and stiffness. The connections are rigid used in bracing frame and unbracing frame before slip and semirigid for both after slip. They are full-strength in terms of strength classification. Before the interstory drift reaches 0.05, no obvious inelastic deformation occurs, indicating that the connections can be easily repaired by repositioning the connection and retightening the bolts after a severe earthquake because the interstory drift will be much less than 0.05 during a severe earthquake. A finite-element model (FEM) was established and validated through a comparison of the finite element analysis (FEA) and test results, and the bolt tension, stress distribution of the beam, and rotation of the column flange splicing connection were obtained from the FEA results. The tension of the bolt in the beam web decreased slightly, while the tension of the bolt in the beam flange decreased to 60–70% of the original pre-tension when the interstory drift reached 0.06. The column flange splice connection is rigid. Simplified formulas for joint strength were deduced and validated by testing and FEA.

Behavior of RCS Connections with Void Web Under Cyclic Load Reversals

In this study, the inelastic cyclic behavior of hybrid connections consisting of reinforced concrete column and steel beams (RCS) was investigated. The experimental results from the lateral load testing of four interior RCS subassembly connections are presented. The first specimen was designed based on the ASCE Guidelines 1994, with connection details based on the study of Liang and Parra-Montesinos (2004), while another specimen was a proposed joint detail. The joint detail was developed to overcome the main problems with RCS frame systems, which is constructability. The behavior of the beam-column joints was evaluated in terms of strength capacity, stiffness degradation, energy dissipation, and joint shear distortion. Comparing all specimens based on the load-displacement hysteresis curves indicated that the specimen with the combination of ABP and EBP had relatively better performance in terms of strength, stiffness, and energy dissipation. ABP and EBF in the joint with a void web were able to withstand joint shear deformation exceeding 0.01 rad, with only low to medium level of damage. EBF was proven to be very effective in providing confinement and reducing the damage level in the joint panel. The existence of a void web did not affect the reduction of joint shear strength.

STUDY ON THE MECHANICAL PROPERTIES OF COLD-FORMED STEEL FRAMED SHEAR WALL WITH SLITS

In order to study the mechanical behavior of the cold-formed steel framed shear wall with slits (CFS-WS) which is suitable for low-rise and multi-story cold-formed thin-walled steel buildings, pseudo-static tests of 1 ordinary CFS-WS and 3 buckling-restrained CFS-WS were conducted to gain the mechanical properties of CFS-WS, including the failure modes, load-displacement hysteresis curves, skeleton curves and energy dissipation capacities, and the design value of shear capacity was put forward. The test results indicates that the CFS-WS relies on the torsion-recovery-reverse torsion of steel plate between vertical slits and the deformation of the steel frame to resist horizontal loads and dissipate energy. The steel plate tears and the end of the hat column buckles when the CFS-WS is broken. The CFS-WS has good bearing capacity, plasticity, ductility and energy dissipation capacity; however, the rheostriction of its load-displacement hysteresis curve is rather severe. Compared with ordinary CFS-WS, the buckling-restrained CFS-WS has higher shear stiffness, bearing capacity and energy dissipation capacity, and the rheostriction of its load-displacement hysteresis curve is mitigated. Furthermore, the stiffeners and the cold-formed steel beams and columns are connected to form a steel frame through the stiffener connectors, which can effectively enhance the early shear stiffness, bearing capacity and energy dissipation capacity of CFS-WS, and greatly improve the seismic performance of the structure.

Experimental Investigation on Seismic Behaviour of Hybrid Precast Beam–column Joints with Different Connection Configurations

ABSTRACT Precast beam–column connections, which are difficult to prefabricate and assemble, are critical members of concrete frames in high seismic regions. In this study, a novel type of precast hybrid connection with different connection configurations is developed for an easy and rapid construction. This steel–concrete connection involves a concrete column with an embedded steel skeleton, a concrete beam with an embedded H-steel, and a connection device including steel band plates and high-strength bolts. To investigate the effectiveness of the proposed connections, three precast hybrid beam–column joints and one monolithic specimen were subjected to reversed cyclic loading and tested. During the test, load–displacement hysteresis curves and failure modes were obtained. The seismic behaviour was investigated in terms of stiffness degradation, load-carrying capacity, energy dissipation, ductility, and shear deformation in the joint core region. Experimental results indicated that the proposed precast hybrid connections exhibited satisfactory performance in terms of ductility, energy dissipation, rotation capacity, strength, and stiffness. The shear deformation of the proposed hybrid connections was reduced owing to the effective confinement of the steel skeleton, while the shear strength improved. Plastic hinges of precast joints with a square steel tube occurred in the beams, and these specimens exhibited flexural failure, which is consistent with the principle of strong columns and weak beams. Therefore, these proposed connections can resist high seismic loads.

Experimental study of precast beam-to-column joints with steel connectors under cyclic loading

This article investigated the seismic performance of a new type of precast concrete beam-to-column joint with a steel connector for easy construction. Five interior beam-to-column joints, four precast concrete specimens, and one monolithic joint were tested under reversed cyclic loading. The main variables were the embedded H-beam length, web plate or stiffening rib usage, and concrete usage in the connection part. The load–displacement hysteresis curves were recorded during the test, and the behavior was investigated based on displacement ductility, deformability, skeleton curves, stiffness degradation, and energy dissipation capacity. The results showed that the proposed beam-to-column joint with the web plate in the steel connector exhibited satisfactory behavior in terms of ductility, load capacity, and energy dissipation capacity under reversed cyclic loading, and the performance was ductile because of the yielding of the web plate. Therefore, the proposed joint with the web plate could be used in high seismic regions. The proposed joint without the web plate exhibited similar behavior to the monolithic specimen, indicating that this joint could be used in low or moderate seismic zones. Furthermore, the utilization of the web plate was vital to the performance of this system.