Role of hysteretic damping in seismic response of the ground under large earthquakes

2014 ◽  
pp. 125-137
Author(s):  
N. Yoshida
Keyword(s):  
Seismic Response ◽  
Hysteretic Damping ◽  
Large Earthquakes

ROLE OF STRUCTURAL DETAILS IN ALTERING THE EXPECTED SEISMIC RESPONSE OF BASE-ISOLATED BRIDGES

2002 ◽  
Vol 16 (2-3) ◽  
pp. 413-428 ◽  
Author(s):  
M.T.A. CHAUDHARY ◽  
M. ABE ◽  
Y. FUJINO
Keyword(s):  
Seismic Response ◽  
Structural Details ◽  
Isolated Bridges

Dissecting large earthquakes in Japan: Role of arc magma and fluids

Island Arc ◽  
2010 ◽  
Vol 19 (1) ◽  
pp. 4-16 ◽  
Author(s):  
Dapeng Zhao ◽  
M. Santosh ◽  
Akira Yamada
Keyword(s):  
Large Earthquakes ◽  
Arc Magma

Role of the creeping segment in the synchronization of earthquake cycles on oceanic transform faults revealed by numerical simulations in the framework of rate-and-state friction

2020 ◽  
Author(s):  
Meng Wei ◽  
Pengcheng Shi
Keyword(s):  
Seismic Data ◽  
Numerical Models ◽  
General Idea ◽  
Partial Rupture ◽  
Transform Faults ◽  
Seismic Slip ◽  
Rate And State Friction ◽  
Large Earthquakes ◽  
Earthquake Cycles

<p>Synchronization behavior of large earthquakes, rupture of nearby faults close in time for many cycles, has been reported in many fault systems. The general idea is that the faults in the system have similar repeating interval and are positively coupled through stress interaction. However, many details of such synchronization remain unknown. Here, we built numerical models in the framework of rate-and-state friction to simulate earthquake cycles on the west Gofar fault, an oceanic transform fault in the East Pacific Rise. Our model is consisted of two seismic segments, separated by a creeping segment, for which the size and location is constrained by seismic data. The parameters in the seismic segments were set to reproduce M6 earthquakes every 5 years, to be consistent with observation. We varied the parameters in the creeping segment to understand its role on earthquake synchronization. We found that the width and the strength of the creeping segment will determine the synchronization of earthquake cycles on the two seismic segments. When the creeping segment is relatively narrow or weak, the system will become synchronized quickly and the synchronization remains for many cycles. When it is relatively wide or strong, the earthquake cycles on the two segments are not related but could be synchronized by chance. In both cases, earthquakes tend to rupture the entire seismic segment. Between these two end-member situations, the system fluctuated between synchronization and non-synchronization on the time scale of 5-10 cycles. The switch always happens when the partial rupture of the seismic segment occurs, resulting in moderate size earthquakes (M4-5) and earthquake cycle shift, which is likely caused by stress interaction through the creeping segment. Here, we conclude that the co-seismic slip and aseismic after slip in the creeping segment could promote the synchronization of earthquake cycles on oceanic transform faults, and likely in other tectonic systems. In addition, the average seismic ratio of the entire fault can be quite low, ranging between 0.2-0.4 because of the barrier segment. We suggest that the existence of creep segments contributed significantly to the well-observed low seismic ratio on oceanic transform faults.</p>

scholarly journals The Role of Shear Wave Velocity and Non-Linearity of Soil in the Seismic Response of a Coupled Tunnel-Soil-Above Ground Building System

Geosciences ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 473 ◽  
Author(s):  
Glenda Abate ◽  
Salvatore Grasso ◽  
Maria Rossella Massimino
Keyword(s):  
Seismic Response ◽  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Dynamic Properties ◽  
Kinematic Hardening ◽  
System Response ◽  
Flow Rule ◽  
Elastic Model

The presence of tunnels close to aboveground structures may modify the response of these structures, while the contrary is also true, the presence of aboveground structures may modify the dynamic response of tunnels. In this context, the dynamic properties of the soil through which the aboveground and underground structures are “connected” could play an important role. The paper reports dynamic FEM (Finite Element Method) analyses of a coupled tunnel-soil-above ground structure system (TSS system), which differ in regards to the soil shear wave velocity and in turns for the damping ratio, in order to investigate the role of these parameters in the full-coupled TSS system response. The analyses were performed using three different seismic inputs. Moreover, the soil non-linearity was taken into account adopting two different constitutive models: i) an equivalent linear visco-elastic model, characterized by degraded soil shear moduli and damping ratios, according to suggestions given by EC8 in 2003; and ii) a visco-elasto-plastic constitutive model, characterized by isotropic and kinematic hardening and a non-associated flow rule. The seismic response of the system was investigated in the time and frequency domains, in terms of: acceleration ratios; amplification ratios and response spectra; and bending moments in the tunnel.

On a Persistent Misunderstanding of the Role of Hysteretic Damping in Rotordynamics

2004 ◽  
Vol 126 (3) ◽  
pp. 459-461 ◽  
Author(s):  
Giancarlo Genta
Keyword(s):  
Practical Applications ◽  
Hysteretic Damping

Even though the role of damping in rotordynamics has been known for more than half a century, some incorrect statements on the effects of hysteretic damping, particularly in the subcritical range, can be found still in even the most authoritative journals. Although clarified in the 1970s, this issue recently resurfaced with the incorrect statement that hysteretic damping of rotating elements is destabilizing at any speed (even subcritical). The aim of the present paper is to clarify this issue in terms of the practical applications of the theory in an unequivocal way.

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