Seismic design of elements outside of the short low-yield-point steel shear links

Ghadami, A.; Pourmoosavi, Gh.; Ghamari, Ali

doi:10.1016/j.jcsr.2020.106489

Cited by 24 publications

(8 citation statements)

References 27 publications

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“…Except for the M_I damper (inelastic buckling), the ultimate strength exhibited errors <12%. In [39,[53][54][55][56], the results of AISC_341 [57] were compared with FE results for predicting the shear capacity of shear links. In these studies, researchers presented relations [57] with errors of 50%.…”

Section: Accuracy Of the Proposed Relationsmentioning

confidence: 99%

An Innovative Steel Damper with a Flexural and Shear–Flexural Mechanism to Enhance the CBF System Behavior: An Experimental and Numerical Study

Ghamari

Almasi²,

Kim

et al. 2021

Applied Sciences

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An innovative passive energy damper is introduced and studied experimentally and numerically. This damper is designed as the main plate for energy absorption which is surrounded by an octagon cover. In addition to simplicity in construction, it can be easily replaced after a severe earthquake. Experimental test results, as well as finite element results, indicated that, by connecting the cross-flexural plate to the main plate, the mechanism of the plate was changed from flexural to shear. However, the cross_flexural plate always acts as a flexural mechanism. Changing the shear mechanism to a flexural mechanism, on the other hand, increased the stiffness and strength, while it reduced the ultimate displacement. Comparing the hysteresis curve of specimens revealed that models without cross_flexural plates had less strength and energy_dissipating capability than other models. Adding the flexural plate to the damper without connecting to the main plate improved the behavior of the damper, mainly by improving the ultimate displacement. Connecting the cross plate to the web plate enhanced the ultimate strength and stiffness by 84% and 3.9, respectively, but it reduced the ductility by 2.25. Furthermore, relationships were proposed to predict the behavior of the dampers with high accuracy.

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Section: Accuracy Of the Proposed Relationsmentioning

confidence: 99%

An Innovative Steel Damper with a Flexural and Shear–Flexural Mechanism to Enhance the CBF System Behavior: An Experimental and Numerical Study

Ghamari

Almasi²,

Kim

et al. 2021

Applied Sciences

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“…In line with flexural dampers attached between the floor beam and chevron brace, the shear dampers are used, as illustrated in Figure 2, including bare shear plate, 10 stiffened shear plate, 11 I‐shaped, 12 and shear panel 13 . The shear dampers naturally enjoy higher lateral strength and lateral stiffness than flexural dampers.…”

Section: Introductionmentioning

confidence: 99%

Investigating the behavior of an innovative butterfly‐shaped damper: An experimental and numerical study

Van,

Ghamari

2023

Structural Design Tall Build

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SummaryThe concentrically braced frame (CBF) suffered from low dissipating energy capacity although it pertains to a high lateral elastic stiffness and ultimate strength. To overcome the shortcoming, in this paper, an innovative damper made of two butterfly‐shaped plates installed at the end of the diagonal member of the CBF was considered experimentally and numerically. Also, the required equations were presented to design the system. In an experimental study, the damper showed stable hysteresis loops without any degradation in stiffness and strength up to a rotation of 12% (0.12 rad). This rotation capacity is 50% greater than the AISC limitation. Also, the numerical study indicated that by increasing the angle of main plates, the structural parameters are improved as ultimate strength (Fu), 47% to 90%; stiffness (K), 64% to 97%; energy absorption (E), 23% to 11%; and overstrength (Ω), 59% to 96%. By reduction of the damper's height, the parameters Fu, K, E, and Ω are increased by 47% to 76%, 23% to 64%, 49% to 93%, and 23% to 27%, respectively. Moreover, although the geometry of the damper affected the elastic stiffness, the stiffness in the nonlinear zone was independent of the geometry of the damper. Correspondingly, the slenderness limitations were suggested as 15 for height to thickness ratio and 22 for wide to thickness ratio.

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“…The stable hysteretic curves and high energy dissipation capacity are considered to be the most important features of this system. [ 21–24 ] The vertical link acts as a ductile fuse since it absorbs most of the imposed seismic energy. The use of a seismic ductile fuse ensures that only the link is damaged, while the other structural elements remain elastic.…”

Section: Introductionmentioning

confidence: 99%

Utilizing I‐shaped shear links as dampers to improve the behavior of concentrically braced frames

Alshimmeri

Ghamari

Naggar

2021

Structural Design Tall Build

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Summary During the past few decades, concentrically braced frames (CBFs) have become a commonly used load‐resistant bearing system in steel structures, to overcome the post‐earthquake performance issues frequently associated with conventional seismic‐resisting structural systems. CBF systems have high lateral stiffness and lateral strength; however, they have low ductility and a low seismic energy dissipating capacity. Under seismic loading, the diagonal members of a CBF system are susceptible to buckling, causing hysteresis in the compression zone and severely reducing energy absorption. Although the use of steel dampers to enhance the behavior of CBF systems can prevent the buckling of CBF members and improve the hysteretic behavior of braces, their use imposes additional costs on structures. Therefore, in this paper, an I‐shaped steel damper with a shear yield mechanism is introduced which is economical, has a simple construction, and can be easily replaced after an earthquake. The proposed damper is evaluated numerically and parametrically. The results indicate that the proposed damper acts as a ductile fuse that prevents buckling of the diagonal members of a CBF system. It was found that both the web and flange plates contribute to the shear resistance, with the flange carrying approximately 15% of the shear force, as expressed in the equations presented. The overstrength obtained for the damper was found to be greater than the value of 1.5 proposed by the AISC. Equations are presented for the design of the proposed damper and the brace elements connected to the damper.

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Seismic design of elements outside of the short low-yield-point steel shear links

Cited by 24 publications

References 27 publications

An Innovative Steel Damper with a Flexural and Shear–Flexural Mechanism to Enhance the CBF System Behavior: An Experimental and Numerical Study

An Innovative Steel Damper with a Flexural and Shear–Flexural Mechanism to Enhance the CBF System Behavior: An Experimental and Numerical Study

Investigating the behavior of an innovative butterfly‐shaped damper: An experimental and numerical study

Utilizing I‐shaped shear links as dampers to improve the behavior of concentrically braced frames

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