scholarly journals Energy dissipation capacity for waffle-flat-plate structures subjected to bi-directional seismic loadings

2021 ◽  
Vol 248 ◽  
pp. 113220
Author(s):  
David Galé-Lamuela ◽  
Jesús Donaire-Ávila ◽  
Amadeo Benavent-Climent
Keyword(s):  
Energy Dissipation ◽  
Flat Plate ◽  
Plate Structures ◽  
Seismic Loadings ◽  
Energy Dissipation Capacity

Testing of Masonry Structures for Seismic Assessment

1996 ◽  
Vol 12 (1) ◽  
pp. 145-162 ◽  
Author(s):  
G. Michele Calvi ◽  
Gregory R. Kingsley ◽  
Guido Magenes
Keyword(s):  
Energy Dissipation ◽  
Experimental Evaluation ◽  
Unreinforced Masonry ◽  
Seismic Assessment ◽  
Experimental Techniques ◽  
Masonry Buildings ◽  
Masonry Structures ◽  
Seismic Loadings ◽  
Energy Dissipation Capacity ◽  
Reduced Scale

The experimental evaluation of strength, deformability, and energy dissipation capacity of unreinforced masonry buildings subjected to seismic loadings presents unique and complex problems, both for laboratory and field evaluations. The paper addresses these problems, focusing on the relative merits and roles of several experimental techniques, including quasistatic, dynamic, and pseudodynamic loadings at full and reduced scale.

scholarly journals Mechanical behaviour of precast prestressed reinforced concrete beam–column joints in elevated station platforms subjected to vertical cyclic loading

2021 ◽  
Vol 60 (1) ◽  
pp. 818-838
Author(s):  
Haiou Shi ◽  
Jinxia Zhao ◽  
Fangmu Chen ◽  
Junjin Lin ◽  
Jianhe Xie
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Mechanical Performance ◽  
Reinforced Concrete Beam ◽  
Lessons Learned ◽  
Urban Rail Transit ◽  
Rc Structures ◽  
Seismic Loadings ◽  
Column Joint ◽  
Energy Dissipation Capacity

Abstract Precast-reinforced concrete (RC) structures in urban rail transit projects can provide many advantages over their cast-in-place counterparts. However, lessons learned from past earthquakes show that beam-column joints may be a critical point of these structures and can overestimate the mechanical performance under vertical seismic loadings if not properly understood. This paper presents unbonded and bonded prestressed precast RC beam-column joints for elevated station platforms. Prestressed steel strands are used to provide joints with self-centring capacity. The performance of the proposed joints under vertical cyclic loadings is experimentally investigated and compared to that of monolithic joints in this study. The obtained results demonstrate the good properties of the proposed precast joints in terms of bearing capacity, energy dissipation capacity and ductility control. A comparison with a conventional monolithic beam-column joint indicates the better performance against earthquakes of the proposed precast prestressed joints, and the precast joint with symmetric prestressed steel strands in the top and bottom of the beam exhibits better flexural stiffness and energy dissipation capacity.

scholarly journals Hysteretic Behavior and Ultimate Energy Dissipation Capacity of Large Diameter Bars Made of Shape Memory Alloys under Seismic Loadings

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1099
Author(s):  
González-Sanz ◽  
Galé-Lamuela ◽  
Escolano-Margarit ◽  
Benavent-Climent
Keyword(s):  
Energy Dissipation ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
High Cycle Fatigue ◽  
Large Diameter ◽  
Hysteretic Behavior ◽  
Cycle Fatigue ◽  
Seismic Loadings ◽  
Energy Dissipation Capacity ◽  
Energy Dissipation Devices

Shape memory alloys in the form of bars are increasingly used to control structures under seismic loadings. This study investigates the hysteretic behavior and the ultimate energy dissipation capacity of large-diameter NiTi bars subjected to low- and high-cycle fatigue. Several specimens are subjected to quasi-static and to dynamic cyclic loading at different frequencies. The influence of the rate of loading on the shape of the hysteresis loops is analysed in terms of the amount of dissipated energy, equivalent viscous damping, variations of the loading/unloading stresses, and residual deformations. It is found that the log-log scale shows a linear relationship between the number of cycles to failure and the normalized amount of energy dissipated in one cycle, both for low- and for high-cycle fatigue. Based on the experimental results, a numerical model is proposed that consists of two springs with different restoring force characteristics (flag-shape and elastic-perfectly plastic) connected in series. The model can be used to characterize the hysteretic behavior of NiTi bars used as energy dissipation devices in advanced earthquake resistant structures. The model is validated with shake table tests conducted on a reinforced concrete structure equipped with 12.7 mm diameter NiTi bars as energy dissipation devices.

scholarly journals Energy Capacity of Waffle-Flat-Plate Structures with Hysteretic Dampers Subjected to Bidirectional Seismic Loadings

2020 ◽  
Vol 10 (9) ◽  
pp. 3133
Author(s):  
Jesús Donaire-Ávila ◽  
David Galé-Lamuela
Keyword(s):  
Numerical Model ◽  
Flat Plate ◽  
Dissipated Energy ◽  
Seismic Capacity ◽  
Plate Structures ◽  
Equivalent Number ◽  
Seismic Loadings ◽  
Number Of Cycles ◽  
Hysteretic Dampers ◽  
Ground Motion Records

This study investigates the capacity, in terms of energy, of waffle-flat-plate (WFP) structures with hysteretic dampers subjected to biaxial seismic actions. A numerical model was developed and calibrated with the experimental results obtained from shake-table testing carried out on a WFP specimen subjected to biaxial seismic loads. Then the WFP system was retrofitted with hysteretic dampers—slit-plate dampers (SPDs)—and the numerical model was subjected to different sets of ordinary ground motion records to attain different seismic performance levels (SPLs). Each set of records was applied in a sequence of scaled seismic simulations until the SPL of near collapse was achieved. The capacity in terms of input energy and dissipated energy are presented for the different SPLs, taking into account the differences observed under unidirectional and bidirectional seismic loadings. Furthermore, the level of damage (i.e., accumulated plastic deformations), the level of ductility and the relationship between them—expressed as equivalent number of cycles—are also shown for both the WFP system and the hysteretic dampers. The seismic capacity of the WFP system is found to be significantly enhanced by the inclusion of hysteretic dampers.

The Effects of Shear Reinforcement on the Reversed Cyclic Loading Behavior of Flat Plate Structures

1975 ◽  
Vol 2 (4) ◽  
pp. 572-582 ◽  
Author(s):  
Neil M. Hawkins ◽  
Denis Mitchell ◽  
Samir N. Hanna
Keyword(s):  
Energy Dissipation ◽  
Flat Plate ◽  
Lateral Loads ◽  
Plate Structures ◽  
Maximum Capacity ◽  
Absorption Energy ◽  
Flexural Reinforcement ◽  
Stiffness Characteristics ◽  
The University ◽  
Reversed Cyclic

This paper reports one phase of a research program at the University of Washington on the seismic response of flat plate to column connections. In particular the behavior of connections containing integral beam stirrup reinforcement in the slabs is discussed. The paper compares different approaches for designing that stirrup reinforcement, outlines the benefits of placing stirrup reinforcement in the slab, and gives guidelines as to the design and proper detailing necessary for that stirrup reinforcement. The effects of concentration of the flexural reinforcement in the immediate column region are also examined. Ductility ratios, energy absorption, energy dissipation, and degeneration of stiffness characteristics of the specimens are reported together with the lateral loads for first yielding and maximum capacity of the specimens.

scholarly journals A New Stainless-Steel Tube-in-Tube Damper for Seismic Protection of Structures

2020 ◽  
Vol 10 (4) ◽  
pp. 1410 ◽  
Author(s):  
Guillermo González-Sanz ◽  
David Escolano-Margarit ◽  
Amadeo Benavent-Climent
Keyword(s):  
Stainless Steel ◽  
Energy Dissipation ◽  
Passive Control ◽  
High Strength ◽  
Steel Tube ◽  
Shaking Table ◽  
Width Ratio ◽  
Stainless Steel Tube ◽  
Seismic Loadings ◽  
Energy Dissipation Capacity

This paper investigates a new stainless-steel tube-in-tube damper (SS-TTD) designed for the passive control of structures subjected to seismic loadings. It consists of two tubes assembled in a telescopic configuration. A series of slits are cut on the walls of the exterior tube in order to create a series of strips with a large height-to-width ratio. The exterior tube is connected to the interior tube so that when the brace-type damper is subjected to forced axial displacements, the strips dissipate energy in the form of flexural plastic deformations. The performance of the SS-TTD is assessed experimentally through quasi-static and dynamic shaking table tests. Its ultimate energy dissipation capacity is quantitatively evaluated, and a procedure is proposed to predict the failure. The cumulative ductility of the SS-TTD is about 4-fold larger than that reported for other dampers based on slit-type plates in previous studies. Its ultimate energy dissipation capacity is 3- and 16-fold higher than that of slit-type plates made of mild steel and high-strength steel, respectively. Finally, two hysteretic models are investigated and compared to characterise the hysteretic behaviour of the SS-TTD under arbitrarily applied cyclic loads.

scholarly journals Experimental and Numerical Analysis of the Mechanical Properties of a Pretreated Shape Memory Alloy Wire in a Self-Centering Steel Brace

Processes ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 80
Author(s):  
Bo Zhang ◽  
Sizhi Zeng ◽  
Fenghua Tang ◽  
Shujun Hu ◽  
Qiang Zhou ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Energy Dissipation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Loading Rate ◽  
Effective Elastic Modulus ◽  
Maximum Energy ◽  
Numerical Results ◽  
Energy Dissipation Capacity

As a stimulus-sensitive material, the difference in composition, fabrication process, and influencing factors will have a great effect on the mechanical properties of a superelastic Ni-Ti shape memory alloy (SMA) wire, so the seismic performance of the self-centering steel brace with SMA wires may not be accurately obtained. In this paper, the cyclic tensile tests of a kind of SMA wire with a 1 mm diameter and special element composition were tested under multi-working conditions, which were pretreated by first tensioning to the 0.06 strain amplitude for 40 cycles, so the mechanical properties of the pretreated SMA wires can be simulated in detail. The accuracy of the numerical results with the improved model of Graesser’s theory was verified by a comparison to the experimental results. The experimental results show that the number of cycles has no significant effect on the mechanical properties of SMA wires after a certain number of cyclic tensile training. With the loading rate increasing, the pinch effect of the hysteresis curves will be enlarged, while the effective elastic modulus and slope of the transformation stresses in the process of loading and unloading are also increased, and the maximum energy dissipation capacity of the SMA wires appears at a loading rate of 0.675 mm/s. Moreover, with the initial strain increasing, the slope of the transformation stresses in the process of loading is increased, while the effective elastic modulus and slope of the transformation stresses in the process of unloading are decreased, and the maximum energy dissipation capacity appears at the initial strain of 0.0075. In addition, a good agreement between the test and numerical results is obtained by comparing with the hysteresis curves and energy dissipation values, so the numerical model is useful to predict the stress–strain relations at different stages. The test and numerical results will also provide a basis for the design of corresponding self-centering steel dampers.

scholarly journals Experimental/Numerical Evaluation of Steel Trapezoidal Corrugated Infill Panels with an Opening

2021 ◽  
Vol 11 (7) ◽  
pp. 3275
Author(s):  
Majid Yaseri Gilvaee ◽  
Massood Mofid
Keyword(s):  
Energy Dissipation ◽  
Ultimate Strength ◽  
Steel Plate ◽  
Shear Walls ◽  
Experimental Results ◽  
Structural Performance ◽  
Initial Stiffness ◽  
Infill Panels ◽  
Energy Dissipation Capacity ◽  
Ductility Ratio

This paper investigates the influence of an opening in the infill steel plate on the behavior of steel trapezoidal corrugated infill panels. Two specimens of steel trapezoidal corrugated shear walls were constructed and tested under cyclic loading. One specimen had a single rectangular opening, while the other one had two rectangular openings. In addition, the percentage of opening in both specimens was 18%. The initial stiffness, ultimate strength, ductility ratio and energy dissipation capacity of the two tested specimens are compared to a specimen without opening. The experimental results indicate that the existence of an opening has the greatest effect on the initial stiffness of the corrugated steel infill panels. In addition, the experimental results reveal that the structural performance of the specimen with two openings is improved in some areas compared to the specimen with one opening. To that end, the energy dissipation capacity of the specimen with two openings is obtained larger than the specimen with one opening. Furthermore, a number of numerical analyses were performed. The numerical results show that with increasing the thickness of the infill plate or using stiffeners around the opening, the ultimate strength of a corrugated steel infill panel with an opening can be equal to or even more than the ultimate strength of that panel without an opening.

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