High Energy Dissipation Capacity Research Articles

Reusable and efficient energy-absorbing architected materials via synergy of snap-through instability and inter-locking mechanism

Reusable energy-absorbing materials of high energy dissipation capacity and low rebound force are highly desirable in engineering and daily life. In this work, we design a new type of architected materials consisting of elastic tilted beams and trapezoidal inter-locking structures (ILSs). The tilted beams buckle elastically and snap from undeformed state to a higher-energy state under compression. They are squeezed into the space between ILSs and locked at this configuration when the external load is removed. The energy applied to the structure turns into elastic strain energy of the beams and ILSs, as well as heat generated by friction and snapping motions. This strategy reconciles the conflict between loading bearing capacity and bistability of the structure. The tilted beams are tuned to increase the load they can sustain, and the ILSs are designed to lock the tilted beams. Compared to a counterpart without ILSs, our strategy expands the design space of energy-absorbing architected materials and improves the energy-absorbing capacity greatly. This work opens opportunities for designing reusable and efficient energy-absorbing materials for applications like sports protective equipment and packaging of delicate objects.

Seismic Performance of Superelastic SMA Damper Retrofitted Building

Nonlinear dampers are well known retrofitting system for the building structure, to mitigate seismic hazard. In past, among different type of nonlinear dampers, metallic yield dampers gain significant attention due to its high energy dissipation capacity. However, it has been observed while yield damper reduces floor displacement, but increases floor acceleration and leaves large residual displacement at the end of ground motion. Present study focuses on the application of shape memory alloy (SMA) dampers as an alternative to the yield damper, for retrofitting of building structure under seismic loading. Thus, response analyses are performed for nonlinear building structure without and with yield damper or SMA damper, under a large number of ground motion. Vibration control efficiency of yield and SMA damper are estimated in terms of the absolute maximum values of the floor acceleration, interstory drift ratio, and residual displacement. Response parameters are estimated over wide range of parameters of damper, building structure, and ground motion. Parametric study results revealed that yield damper provides very less acceleration control efficiency and some of cases it become more than uncontrolled structure. In contrast SMA damper slightly improves the acceleration control than yield damper (almost 14 %). In Comparison to the yield damper, SMA damper reduces the interstory drift ratio by 38 % and residual floor displacement by 47 %. Therefore, SMA damper provides major advantage in floor displacement reduction over yield damper, and acts as better re-centring device for seismic retrofitting application.

Seismic response of a RC structure with new self-centering metallic dampers under biaxial near-field ground motions: Shake table tests

A new metallic energy dissipation device (EDD) with self-centering capability is proposed, and its effectiveness in controlling the seismic response of buildings subjected to near-fault earthquakes is investigated experimentally in combination with an inherently very flexible structural system: the RC waffle-flat plate structure. The new EDD combines the high energy dissipation capacity of stainless steel with the super-elastic properties of shape memory alloys. EDDs are installed in a 2/5 scale portion of a prototype RC waffle-flat plate structure designed only for gravity loads and tested on a shake table. The specimen is subjected to two horizontal components of a ground motion scaled in amplitude to represent different levels of seismic hazard at the building site. The RC structure with EDDs performed basically elastic under frequent earthquakes, remained “operational” under the design-level earthquake, and performed within the limits of “operational” and “life safety” under maximum credible earthquakes. The new EDD substantially reduced the maximum residual inter-story drifts —up to 1/10 of those of a conventional metallic EDD without self-centering capability. The response was also compared with a counterpart conventional RC structure without EDDs. The importance of providing the metallic EDDs with self-centering capability is highlighted.

Cyclic Behavior of Autoclaved Aerated Concrete External Panel with New Connector.

In this paper, a new slip-type crossing connector is proposed for autoclaved aerated concrete (ALC) panels with steel frames, and the proposed connector is also studied deeply in terms of seismic performance. The research included pseudo-static tests and finite element simulations. First, the seismic performance of slip-type crossing connectors and standard L-hooked bolts was studied comparatively, including the stability, bearing capacity, stiffness, energy dissipation, and hysteresis performance. ABAQUS 2020 software was used to establish finite element models, and the results of the experiments were verified with simulations on the basis. According to the simulations, a parameter analysis of connector optimization was carried out. The effects of connector thickness and connector plate length on the seismic performance were further investigated. From the experimental and simulation results, the slip-type crossing connector has excellent performance and good assembly efficiency, it can improve the deficiencies of the existing connectors. The comparison demonstrated that the slip-type crossing connector has a complete hysteresis curve, a high energy dissipation capacity, and a 9.7% increase in bearing capacity. The appropriate reduction in connector thickness and plate length can ensure superior seismic performance while saving resources. The finite analysis method can guide the design and implementation of new external ALC panel connectors.

Hysteretic tests of stud connection subjected to combined shear and tension

The hysteretic behaviour of stud connections in the shear direction under the combined action of shear and tension was studied by the push-out test of eight cyclic loading specimens. To compare the difference between cyclic loading and monotonic loading on the shear capacity and the shear–slip curve, eight monotonic loading specimens were designed as reference specimens. The main variables considered in this study were the diameter of the stud, the strength of the concrete, and the magnitude of the tensile force in the stud. Based on the test results, failure modes, shear–slip curves and characteristic points on the curves of all specimens were evaluated. Hysteretic responses such as ductility, strength degradation and energy dissipation of cyclic loading specimens were analysed. The test results show that the diameter of the stud, the strength of concrete and the tensile force of stud connectors have significant effects on the hysteretic performance of stud connections. The stud connection with larger stud diameter and higher concrete grade has higher shear resistance, higher ductility index and higher energy dissipation capacity. In comparison to stud connections under pure shear loading, the hysteretic properties of stud connections with combined action of shear and tension are degraded. The influence of tensile force on the hysteretic performance of stud connections under the combined action of shear and tension would thus need to be taken into consideration in the design of composite structures.

Mechanical properties of curvature-consistent frictional pendulum bearings and isolation performance of spherical reticulated shells

With the increasing demand for isolated long-span spatial structures, the seismic performance of structures during rare earthquakes should be improved. In this study, we proposed a type of curvature-consistent frictional pendulum bearing (CC-FPB) that may induce notable seismic isolation effects in long-period and long-span spatial structures during rare earthquakes. Hysteresis tests were performed on the structure with the CC-FPB, and a refined numerical simulation method was established to analyse the isolation performance of the CC-FPB was established. The accuracy of the simulation method was verified by comparing the simulation results with experimental results. Based on the refined numerical simulation method, the CC-FPB was applied to a single-layer spherical reticulated shell structure, and the dynamic time history response of the structure was analysed. Furthermore, the seismic isolation effect was compared with that of the classical friction pendulum bearing (C-FPB). Parametric analysis was performed for structures with different roof qualities and input ground motions. We also analysed the seismic isolation effect and isolation influence mechanism of the structure with the CC-FPB. The results indicated that the CC-FPB had high isolation performance and energy dissipation capacity. Although the isolation performance had negligible influence on the loading frequency, the energy dissipation capacity and isolation performance increased with the increase in the loading frequency and loading displacement. The isolation efficiency of the isolation structure with the CC-FPB improved in comparison with that of the structure with the C-FPB. The isolation performance and energy dissipation capacity of the isolation structure increased with the increase in the seismic amplitude. The energy dissipation and damping capacity of the CC-FPB improved under high-frequency excitation.

Recycling of waste tire rubber as aggregate in impact-resistant engineered cementitious composites

With the development of modern transportation, the recycling and reusing of waste tires have gradually become a global concern. This paper was indented to develop impact-resistant engineered cementitious composites (ECC) with the application of waste tire rubber as the aggregate. The local PVA fibers, as well as the rubber crumb derived from waste tire with the replacement ratio up to 40 %, were applied to make ECCs. The basic mechanical behaviors of rubber-modified ECC were first investigated with uniaxial compressive and tensile tests. The impact tests of rubber-modified ECC were further conducted under different environmental temperatures ranging from −50 ℃ to 150 ℃, as well as different impact heights from 100 mm to 500 mm. It was concluded that the rubber-modified ECCs are more suitable to be applied as impact-resistant material in cold regions, as the rubber-modified ECC has higher energy dissipation capacity than normal ECC, especially under cold temperatures.

Experimental Study on Seismic Behavior of Precast Bolt-Connected Steel-Members End-Embedded Concrete (PBSEC) Beam-Column Connections

With the rapid development and research of precast concrete frame structures, it is not difficult to find that the structural form and seismic performance of dry-connected precast joints have always been the focus of research. Since this type of structural system is complex, the construction is inconvenient in practical application, and many additional parts need to be installed, this paper develops a kind of precast bolt-connected steel-members end-embedded concrete (PBSEC) beam-column connection to solve the shortcomings of the current dry-connected precast joints. There is no wet work in the assembly process, and all-dry construction and assembly methods are used. There is no need to pour concrete and support formwork, which significantly improves construction efficiency compared to wet and cast-in-situ connections. Low cyclic reversed loading tests were conducted to obtain test data, such as failure mode, hysteresis curve, skeleton curve, stiffness, ductility, and deformation capacity of the precast concrete joint. The failure mode of the PBSEC joints is the buckling failure of the connecting steel plate, leading to a perfect seismic capacity and collapse resistance of the structure. The hysteresis curves of the PBSEC joints are bow-shaped and full in shape, showing high energy dissipation capacity. The bearing capacity of the joints begins to rise rapidly at the initial loading stage and then decreases slowly after reaching the peak, which is an ideal shape. By summarizing the average peak load, strength degradation coefficient, loop energy per cycle, loop energy per level, and cumulative energy damping coefficient, it is found that the joint using 10 mm thick Q235 steel can obtain the most suitable failure mode and obtain the best energy dissipation performance. When the strength of the steel plate material increases, the energy dissipation performance of the joint drops.

Mechanical performance of mortise-tenon joints reinforced with self-tapping screws

• Mortise-tenon joints provides a potentially feasible scheme for the development of connection in modern timber construction. • Using self-tapping screw (STS) to reinforce mortise-tenon joint is cost-efficient, convenient, and faster. • The reinforced joints had a better mechanical properties than the unreinforced joint. • The parameters of STS had a significant influence on the reinforcement effect of mortise-tenon joints. This paper presents the results of the mortise-tenon joints reinforced with self-tapping screw (STS) under cyclic loading experiment. Five groups of joints, including one unreinforced group and four reinforced groups, were subjected to low-cycle reversed loading tests, where STS with different diameters and numbers were screwed into the reinforced group. The mechanical behavior of joints such as failure modes, hysteretic and skeleton curves, bending capacities, stiffness, ductility, and energy dissipation were obtained. The results showed that the insertion of STS can effectively reduce the pull-out of tenon and improve the initial stiffness and ductility. The bending capacities of the reinforced groups were significantly improved. In addition, the reinforced groups had a higher energy dissipation capacity in initial cycles under negative loading, while the unreinforced group could maintain a certain energy dissipation capacity during the whole loading process. More STS and a larger diameter of STS could improve the mechanical performance of mortise-tenon joints, but it would also aggravate the damage of joints.

A critical review of cold-formed steel seismic resistant systems: Recent developments, challenges and future directions

Cold-formed steel (CFS) systems have seen an increased application in the past few decades, especially in the construction of low- to mid-rise buildings. CFS members offer considerable structural and environmental advantages, such as low weight, ease and speed of construction, greater manufacturing flexibility, recyclability and low embodied carbon. Despite the significant potential offered by CFS structural systems, the seismic design of lateral force-resisting systems (LFRS) for CFS multi-story buildings is challenging. There are many different types of systems capable of providing the lateral load resistance capacity of the CFS framing, and this paper provides a comprehensive review of the research developments made in CFS braced-wall systems and moment-resisting frames, as the most conventional systems, to study their structural performance and identify the research gaps, challenges, and future directions. The major research developments are summarised in terms of load capacity, stiffness, energy dissipation capacity and failure mode. As an outcome of the crucial review, it was found that CFS LFRSs can generally offer more efficient design solutions regarding seismic characteristics such as high ductility and energy dissipation capacity. Despite a rather large body of research on CFS braced walls, it is necessary to assess the response of these systems in various aspects, such as developing an optimisation framework to withstand the combination of vertical and horizontal loading plus resist the impact of severe fire. With respect to moment-resisting frames, one of the main research needs is to develop systems suitable for multi-story buildings, especially in seismic regions.

Experimental and numerical study on innovated steel Shear Resisting Frame with Haunched Beams (SRFHBs)

Steel shear panels are one of the most significant lateral resisting systems with high ductility and energy dissipation capacity. This paper describes and discusses innovated steel Shear Resisting Frame with Haunched Beams (SRFHBs) with a particular focus on very short link beams. Regarding shear panels performance, the conception of SRFHB emerged with the aim of improving the link beam behavior in Eccentric Bracing Frames (EBFs) as well as architectural constraints and overcoming the span-to-depth ratio limitation provided by the seismic provisions in Moment Resisting Frames (MRFs) which notified especially in tall buildings with framed-tube structural system. SRFHB is comprised of two strong side columns connected to the link beam as the shear fuse in the middle of the span through haunched beams. Application of the haunched configuration makes it comfortable to reach very short links. Shear fuse plays the governing behavior as sacrificing element to keep adjacent members safe. Shear yielding and out-of-plane deformations due to the tension-field action, control the amount of energy dissipation. An experimental program and extensive nonlinear dynamic analyses were conducted to validate the test results and evaluate the seismic behavior of the proposed system and idea in comparison of the conventional EBF. Results indicated that SRFHBs could develop considerable performance with more desirable seismic response than traditional EBFs.

Ordered stereom structure in sea urchin tubercles: High capability for energy dissipation

Tubercles in sea urchin shells serve as a base on the test plates connecting the spine; these undergo compressive or impact stress from the spines. As the volume fraction of the ordered stereom structure in a tubercle increases, the compressive load–displacement curves are gradually characterized by the typical behavior of ceramic foams. Although this ordered stereom structure only exhibits an average porosity of 50.6%, it also exhibits high fracture resistance and energy dissipation capacity. Such remarkable behavior of the ordered stereom structure is attributed to its unique hierarchical microstructure. Specifically, at the macroscale, the stereom structure is periodic. It has uniformly distributed pores that are typically round, which can effectively reduce the stress concentration around the pores, and the ordered arrangement of the trabeculae along the axial direction of the tubercle bears the most compressive stress. The trabeculae present a bottleneck shape with a specific dimension, ensuring the best fracture resistance with a relatively higher porosity. Furthermore, crack deflection in the trabeculae changes the local fracture mode of the mineral, thereby increasing the crack surface area. Statement of significanceThe connecting bases of the spines in sea urchin shell, known as tubercle, effectively undergo the compressive stress or impact stress from the spines. An ordered stereom structure is found in the tubercle, and it shows an excellent fracture resistance and energy dissipation capacity. Such a fantastic behavior of the ordered stereom structure mainly takes advantage of its unique hierarchical microstructure. The stereom structure presents a periodic structure on macroscale, the trabeculae show a bottleneck shape with a specific dimension to guarantee the best fracture resistance with a relatively higher porosity, and the soft fillers among CaCO3 nanoparticles in a trabecula cause consecutive crack deflections.

Investigation of the Effects of Superstructure Damping Ratio on Buildings with Lead Rubber Bearings under Earthquake Effect

Kurşun çekirdekli elastomer (KÇE) yalıtım birimleri yüksek enerji sönümleme kapasiteleri nedeniyle en çok kullanılan sismik yalıtım birimleri arasında yer almaktadır. Bununla birlikte, yapılan deneysel çalışmalar; kurşun çekirdekte tersinir yükler altında meydana gelen sıcaklık artışının, kurşunun akma dayanımını düşürerek karakteristik dayanımda azalmaya yol açtığını ve bu etkiyi dikkate almanın önemli olduğunu ortaya koymaktadır. Sismik yalıtımlı binalarda yalıtım sisteminin yanı sıra, üstyapı da kendi iç sönümü sayesinde bir dereceye kadar enerji sönümleme özelliğine sahiptir. Ancak, bu yapıların tasarımlarında ve bu tür yapıları ele alan araştırma çalışmalarında üstyapı için farklı sönüm oranlarının kullanıldığı görülmektedir. Bu çalışmada, üstyapı sönümünün, (i) taban ankastre betonarme binalara benzer şekilde % 5 alınması, (ii) % 2 gibi daha küçük bir değer alınması ya da (iii) tamamen ihmal edilmesi durumunda sismik yalıtımlı binaların kurşun çekirdek ısınmasına bağlı davranışlarının değişimi incelenmiştir. Sismik yalıtımlı betonarme bir bina, OpenSees programında, kurşun çekirdek ısınmasının dayanım üzerindeki etkisi göz önünde bulundurularak modellenmiş ve zaman tanım alanında yapılan doğrusal olmayan analizlerden elde edilen kat ivmeleri, kurşun çekirdekteki sıcaklık artışı, yalıtım birimi kesme kuvvetleri ve deplasmanları gibi tepkiler incelenmiştir. Sonuçlar, özellikle kat ivmelerinin önemli ölçüde değişebildiğini ve farklı üstyapı sönüm oranlarıyla elde edilen kat ivmelerinin farklı sınır aralıklarında olabileceğini ortaya koymuştur.

Seizmičko ponašanje spregnutih posmičnih stijena s AB okvirom ojačanim čelikom i ugrađenom perforiranom čeličnom pločom

Experiments are conducted on five shear wall specimens of varying design and structural measures in order to investigate seismic behaviour of a composite shear wall with the steel-reinforced concrete frame and an embedded perforated-steel plate. In addition, low-cyclic load is applied on test specimens that have a shear span ratio of 1.5. Using the experimental data, the bearing capacity, stiffness, ductility, hysteretic energy, and failure characteristics of five specimens are analysed. The results show that the composite shear wall (CSW) with the steel reinforced concrete frame (SRCF) and embedded steel plate (ESP) has higher bearing capacity, better ductility, slower degradation of stiffness, and higher energy dissipation capacity, as compared to an ordinary reinforced concrete shear wall. Moreover, its seismic behaviour can be improved by using the ESP of an appropriate thickness. For the ESPs of identical thickness, the results show that the specimen that uses steel ties exhibits better seismic behaviour than those using welding studs. Finally, a computing model that can calculate the bearing capacity of the CSWs is developed. A comparison of calculated and measured results shows that the results are close to each other.

Seismic behavior of a novel bolt-connected horizontal joint for precast RC wall panel structures: Experimental and numerical analysis

In this study, a novel connection consisting of high-strength bolts and connecting steel plates used for horizontal joints of fully precast RC wall panel structures was proposed. Four precast wall panels were jointed using the novel connection and tested under reversed cyclic load to investigate the seismic performance. Several variables, such as the spacing of the stirrups, the diameter of the bolts, the thickness of the steel plates, and the height-to-width ratio, were considered in the tests. Mechanical behaviors, including failure mode, hysteresis curve, strength, ductility, stiffness and energy dissipation capacity, were discussed through the comparison among the specimens. Test results show that: (1) All the four specimens failed at the two flange edges of the wall panels due to severe concrete crushing. Failure modes are bending failure; (2) Wall panel structures with bolt-connected joint had good integrity and mechanical behaviors including high carrying capacity, excellent ductility and comparable energy dissipation capacity. In addition, a finite element model was calibrated with the test results and then a series of parametric analyses were conducted. It is concluded that the bearing capacity of the bolt-connected wall panel gradually increases with the decrease of the stirrup spacing, the increasing thickness of connecting steel plate and the increasing number of high strength bolts. Specifications of stirrup spacing, connecting steel plate thickness and bolt number were recommended through the numerical analysis.

Experimental Behavior of UHPC Shear Walls with Hybrid Reinforcement of CFRP and Steel Bars under Lateral Cyclic Load

A new kind of structural system, ultrahigh-performance concrete (UHPC) shear walls reinforced with carbon fiber–reinforced polymer (CFRP) and steel bars, is proposed in this study. CFRP bars were used in the web region of the shear walls to obtain favorable self-centering capacity, and steel bars in the boundary element were used to achieve high energy-dissipation capacity. Quasi-static tests of four shear-wall specimens were conducted. The self-centering capacity, energy-dissipation capacity, and strength and stiffness degradation of the specimens were analyzed. The tested UHPC shear walls exhibited favorable self-centering and good energy-dissipation capacity. The experimental results showed that the stress in the CFRP bars is the key factor to determine the effectiveness of CFRP bars. The authors proposed a formula for calculating the proper location of CFRP bars and a design axial-load ratio limit for UHPC shear walls with hybrid CFRP/steel reinforcement bars.

Behaviour of buckling-restrained steel plate shear wall with concrete-filled L-shaped built-up section tube composite frame

To improve the space utilisation rate and seismic performance of high-rise buildings, a new seismic structural system, this paper proposes a buckling-restrained steel plate shear wall (SPSW) with a concrete-filled L-shaped built-up section tube composite frame. In this composite shear wall system, the columns in the frame are composed of hot-rolled carbon steel H-section members and carbon steel square hollow section tubes, which are connected by steel plates and filled with concrete, and the SPSW is comprised of an embedded steel plate and several pairs of cold-formed steel hat-section buckling-restraining strips. To study the seismic performance of this new type of shear wall system, two specimens were prepared and tested under a horizontal cyclic load. The test results showed that the two specimens had a high bearing capacity, good ductility, and good energy dissipation capacity. This indicated that the new shear wall system was reliable and effective at resisting lateral forces. Finite element models were established and validated against experimental results. Based on the results of a parametric analysis, a value of 0.85 was proposed for coefficient η to modify the method based on the plate–frame interaction theory, which could be used to calculate the bearing capacity of the buckling-restrained SPSW with the concrete-filled L-shaped built-up section tube composite frame.

Self-Healing, Anti-Fatigue, antimicrobial ionic conductive hydrogels based on Choline-Amino acid polyionic liquids for Multi-Functional sensors

Conductive hydrogels have recently attracted extensive attention due to their broad application prospects in flexible electronic devices and artificial intelligence. However, it is still a great challenge to develop integrated conductive hydrogels with excellent mechanical properties, efficient self-healing ability and high sensitivity. Moreover, most conductive hydrogels have no antimicrobial activity, which may lead to microbial infection during their applications. Herein, a series of versatile ionic conductive hydrogels based on choline-amino acid polyionic liquids(Cho-AA PILs) were designed by double network (DN) methodology. Owing to the reversible nature of dynamic coordination interaction, including metal coordination bonds, hydrogen bonds and electrostatic interactions, the resultant PIL hydrogels exhibited efficient self-healing ability, high energy dissipation capacity and outstanding fatigue resistance. The incorporation of Cho-AA PILs endowed hydrogels with not only high antimicrobial activity but also sensitive, rapid and stable strain sensing ability. The gauge factor(GF) and response time of PIL flexible sensors were 2.65 and 100 ms, respectively. During 1000 cycles, the electrical response signal of the strain sensor still remained stable. Significantly, PIL flexible sensors were able to monitor and distinguish large human body motions and subtle physiological activities and show sensitivity to pressure and handwriting. In addition, PIL hydrogels exhibited excellent biocompatibility. These results predicted that the prepared PIL hydrogels possess promising application prospects in the fields of artificial intelligence and biomedical engineering.

Seismic performance of beam to box-column connection by a short stub beam

In this paper, the behaviour of an innovative connection proposed to connect steel beams to box-columns is investigated experimentally and numerically. This connection eliminates the need for using continuity plate inside the box-column by introducing a new load transfer mechanism. The connection also benefits from the extended end-plate connection in its configuration, allowing for fast erection and cost-effectiveness. Two full-scale specimens were tested under reversed load cycles, and parameters including connection rigidity, ductility, and energy dissipation capacity were evaluated. In all specimens, the plastic hinge formed within the beam, and its location complied with the requirements of extended end-plate connections. The specimens could resist 6% story drift with stable hysteretic curves, revealing their qualification for use in special moment resisting frames (SMF) based on seismic provisions of AISC 341–16. Moreover, the specimens showed high ductility and energy dissipation capacity along with reasonable stiffness degradation. Finally, the unnecessity of continuity plates was investigated, which confirmed that the continuity plates were not required in the proposed connection.

Experimental investigation of link beams with perforated web section in eccentrically braced frames

Eccentrically braced frame (EBF) system is one of the most effective lateral loads resisting systems for steel structures. In these systems, links are designed in such a way that they yield in shear not only to provide high ductility and rigidity but also to provide a high energy dissipation capacity. In particular, as the internal forces to be considered for the design of the members outside of the links must be calculated with the amplification factor based on the yielding of the links, the magnitude of the internal forces may become so large that they may not be met by the adjacent members. Therefore, it is challenging to develop an economic design for adjacent members and connections because of the high level of design loads obtained by the amplification factor. This paper studies the effect of the perforation arrangement in the web of shear link beams in eccentrically braced frames. Both experimental and numerical investigation were conducted to demonstrate the effectiveness of the link beam with slotted perforations in the web portion. Seven equivalent isolated link beam specimens with various slot-hole patterns were tested under quasi-static cyclic loading. The results of the study indicate that using slot-holes in the web portion reduces the link shear capacity significantly. The results also show that the failure mechanism of reduced link sections was controlled by fracture at end of the slot-holes and inelastic rotation capacities were varying between 0.025 rad and 0.065 rad depending on the slot-hole patterns.