Estimating settlements in dry sands during earthquakes

1976 ◽  
Vol 13 (4) ◽  
pp. 355-363 ◽  
Author(s):  
W. D. L. Finn ◽  
P. M. Byrne
Keyword(s):  
Empirical Relationship ◽  
Time History ◽  
Earthquake Excitation ◽  
Wide Range ◽  
History Of ◽  
Linear Viscoelastic ◽  
Earthquake Scaling ◽  
Shear Strains ◽  
Surface Settlements ◽  
Settlement Distribution

An analytical method for predicting the settlement of a horizontal stratum of dry sand subjected to earthquake excitation is presented. An equivalent linear viscoelastic dynamic analysis is used to determine the time-history of shear strains at various levels within the stratum. The vertical strains caused by these shear strains are calculated by an empirical relationship shown to be in close agreement with laboratory test data over a wide range of relative densities. This allows the settlement distribution with depth to be calculated as a function of time.The method was applied to a 50 ft (15 m) stratum of sand. A base acceleration corresponding to 0–10 s of the N–S component of El Centro earthquake was used. Settlement distribution vs. depth, as well as surface settlements for various relative densities and earthquake scaling factors are shown. The effect of surcharge loading on settlements is investigated in an approximate manner.The results may be used to estimate differential settlement of a structure due to an earthquake. The results show that while the compaction of the upper layers may be sufficient to reduce the settlements due to static loads to tolerable amounts, deep-seated settlements will still occur during an earthquake.

Thermal Response of a Viscoelastic Rod Under Cyclic Loading

1974 ◽  
Vol 41 (1) ◽  
pp. 229-233 ◽  
Author(s):  
S. Mukherjee
Keyword(s):  
Cyclic Loading ◽  
Thermal Response ◽  
Time History ◽  
Thermomechanical Coupling ◽  
Large Strains ◽  
Driving Frequency ◽  
Wide Range ◽  
History Of ◽  
Complex Young’S Modulus ◽  
Viscoelastic Rod

Thermal response of a viscoelastic rod under cyclic loading is discussed by determining the stresses and temperature in a viscoelastic rod insulated on its lateral surface and driven by a sinusoidal stress at one end. Temperature dependence of the complex Young’s modulus of the rod and the effect of thermomechanical coupling are included in the analysis. A method of finite differences is used to directly determine the steady-state stresses and temperature without obtaining the complete time history of the process. The iterative algorithm used is very efficient and converges rapidly for a wide range of driving stress amplitudes and frequencies. It is found that rapid rise of temperature to dangerous levels occurs for relatively low values of driving stress amplitudes, especially if the driving frequency is close to one of the critical frequencies of the rod. Drastic softening of the rod leads to large strains. Thus failure of the rod could occur at low values of the driving stress.

scholarly journals Tracking patchy pulsating aurora through all-sky images

2017 ◽  
Vol 35 (4) ◽  
pp. 777-784 ◽  
Author(s):  
Eric Grono ◽  
Eric Donovan ◽  
Kyle R. Murphy
Keyword(s):  
Time History ◽  
Image Data ◽  
Auroral Oval ◽  
Automatic Identification ◽  
Inner Magnetosphere ◽  
Wide Range ◽  
History Of ◽  
Initial Results ◽  
Automatic Technique

Abstract. Pulsating aurora is frequently observed in the evening and morning sector auroral oval. While the precipitating electrons span a wide range of energies, there is increasing evidence that the shape of pulsating auroral patches is controlled by structures in near-equatorial cold plasma; these patches appear to move with convection, for example. Given the tremendous and rapidly increasing amount of auroral image data from which the velocity of these patches can be inferred, it is timely to develop and implement techniques for the automatic identification of pulsating auroral patch events in these data and for the automatic determination of the velocity of individual patches from that data. As a first step towards this, we have implemented an automatic technique for determining patch velocities from sequences of images from the Time History of Events and Macroscale Interactions during Substorms (THEMIS) all-sky imager (ASI) and applied it to many pulsating aurora events. Here we demonstrate the use of this technique and present the initial results, including a comparison between ewograms (east–west keograms) and time series of patch position as determined by the algorithm. We discuss the implications of this technique for remote sensing convection in the inner magnetosphere.

Characterization of Real Eigenvalues in Linear Viscoelastic Oscillators and the Nonviscous Set

2013 ◽  
Vol 81 (2) ◽  
Author(s):  
Mario Lázaro ◽  
José L. Pérez-Aparicio
Keyword(s):  
Time History ◽  
Negative Numbers ◽  
Closed Intervals ◽  
Convolution Integrals ◽  
History Of ◽  
Linear Viscoelastic ◽  
One Step ◽  
Damping Model ◽  
Theoretical Results

In structural dynamics, energy dissipative mechanisms with nonviscous damping are characterized by their dependence on the time-history of the response velocity, which is mathematically represented by convolution integrals involving hereditary functions. The widespread Biot damping model assumes that such functions are exponential kernels, which modify the eigenvalues' set so that as many real eigenvalues (named nonviscous eigenvalues) as kernels are added to the system. This paper is focused on the study of a mathematical characterization of the nonviscous eigenvalues. The theoretical results allow the bounding of a set belonging to the real negative numbers, called the nonviscous set, constructed as the union of closed intervals. Exact analytical solutions of the nonviscous set for one and two exponential kernels and approximated solutions for the general case of N kernels are developed. In addition, the nonviscous set is used to build closed-form expressions to compute the nonviscous eigenvalues. The results are validated with numerical examples covering single and multiple degree-of-freedom systems where the proposed method is compared with other existing one-step approaches available in the literature.

scholarly journals Using a moving load to simultaneously detect location and severity of damage in a simply supported beam

2019 ◽  
Vol 25 (15) ◽  
pp. 2108-2123
Author(s):  
Mohsen Mousavi ◽  
Damien Holloway ◽  
J C Olivier
Keyword(s):  
Structural Damage ◽  
Moving Load ◽  
Time History ◽  
Static Deflection ◽  
Cracked Beam ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Damage Location ◽  
Wide Range ◽  
History Of

This paper demonstrates the feasibility of simultaneously identifying both the location and severity of structural damage in a beam by using two independent moving load experiments. First, a simple but sufficiently accurate single degree of freedom model is presented to simulate the structure efficiently over a wide range of relevant inputs. We then introduce a damage sensitive feature (DSF) based on the integral of the velocity time history of the beam at its midspan when the load moves over the beam. A critical velocity, a function only of the beam’s first natural frequency and length, is obtained for the proposed DSF, upon which the damage can be located more accurately. The only required data for the damage detection is the midspan velocity-time history of the cracked beam subjected to a moving load, and the midspan static deflection of the intact beam subjected to a load of the same magnitude. In the last section of this paper, the capability of the proposed DSF is examined in the presence of noise. The results demonstrate the capability of the proposed method to find both the damage location and severity successfully, and methods for further reducing the effects of noise are suggested.

scholarly journals On the role of the history force for inertial particles in turbulence

2015 ◽  
Vol 782 ◽  
pp. 567-593 ◽  
Author(s):  
Anton Daitche
Keyword(s):  
Equations Of Motion ◽  
Time History ◽  
Considerable Effect ◽  
Inertial Particles ◽  
Full Time ◽  
Preferential Concentration ◽  
Wide Range ◽  
History Of ◽  
Particle Parameters ◽  
History Force

The history force is one of the hydrodynamic forces that act on a particle moving through a fluid. It is an integral over the full time history of the particle’s motion and significantly complicates the equations of motion (accordingly it is often neglected). We present here a study of the influence of this force on particles moving in a turbulent flow, for a wide range of particle parameters. It is shown that the magnitude of the history force can be significant and that it can have a considerable effect on the particles’ slip velocity, acceleration, preferential concentration and collision rate. We also investigate the parameter dependence of the strength of these effects.

Numerical Approaches to Movement of Suspended Cable under Wind Based on VFIFE

2011 ◽  
Vol 255-260 ◽  
pp. 1252-1255
Author(s):  
Zhen Yu Zhong
Keyword(s):  
Low Frequency ◽  
Time History ◽  
Cable Structure ◽  
Suspended Cable ◽  
Linear Behavior ◽  
Wide Range ◽  
Non Linear ◽  
History Of ◽  
Linear Problems ◽  
Dynamics Response

Dynamics response of suspended cable structure is studied in this paper. It is difficult to analyze this type of structure because of non-linear behavior. VFIFE is an efficient method to solve non-linear problems and applied to calculate movement of cable on wide range. Some results are obtained from time history of cable vibration, such as galloping and characteristic frequency. A case of cable movement under wind shows that low frequency in wind speed is main fact impacting on wave of cable.

Group Experiences and Individual Differences in Stuttering

2019 ◽  
Vol 62 (12) ◽  
pp. 4335-4350 ◽  
Author(s):  
Seth E. Tichenor ◽  
J. Scott Yaruss
Keyword(s):  
Individual Differences ◽  
Support Groups ◽  
Support Group ◽  
Affective States ◽  
Life Outcomes ◽  
Self Help ◽  
Wide Range ◽  
Group Experiences ◽  
History Of ◽  
Adults Who Stutter

Purpose This study explored group experiences and individual differences in the behaviors, thoughts, and feelings perceived by adults who stutter. Respondents' goals when speaking and prior participation in self-help/support groups were used to predict individual differences in reported behaviors, thoughts, and feelings. Method In this study, 502 adults who stutter completed a survey examining their behaviors, thoughts, and feelings in and around moments of stuttering. Data were analyzed to determine distributions of group and individual experiences. Results Speakers reported experiencing a wide range of both overt behaviors (e.g., repetitions) and covert behaviors (e.g., remaining silent, choosing not to speak). Having the goal of not stuttering when speaking was significantly associated with more covert behaviors and more negative cognitive and affective states, whereas a history of self-help/support group participation was significantly associated with a decreased probability of these behaviors and states. Conclusion Data from this survey suggest that participating in self-help/support groups and having a goal of communicating freely (as opposed to trying not to stutter) are associated with less negative life outcomes due to stuttering. Results further indicate that the behaviors, thoughts, and experiences most commonly reported by speakers may not be those that are most readily observed by listeners.

Introduction: Emotion, History and the Arts

2018 ◽  
Vol 7 (2) ◽  
pp. 117-128 ◽  
Author(s):  
Erin Sullivan ◽  
Marie Louise Herzfeld-Schild
Keyword(s):  
Historical Change ◽  
Carson Mccullers ◽  
Emotional Life ◽  
Review Section ◽  
The Arts ◽  
Wide Range ◽  
War Correspondents ◽  
History Of ◽  
Johan Huizinga

This introduction surveys the rise of the history of emotions as a field and the role of the arts in such developments. Reflecting on the foundational role of the arts in the early emotion-oriented histories of Johan Huizinga and Jacob Burkhardt, as well as the concerns about methodological impressionism that have sometimes arisen in response to such studies, the introduction considers how intensive engagements with the arts can open up new insights into past emotions while still being historically and theoretically rigorous. Drawing on a wide range of emotionally charged art works from different times and places—including the novels of Carson McCullers and Harriet Beecher-Stowe, the private poetry of neo-Confucian Chinese civil servants, the photojournalism of twentieth-century war correspondents, and music from Igor Stravinsky to the Beatles—the introduction proposes five ways in which art in all its forms contributes to emotional life and consequently to emotional histories: first, by incubating deep emotional experiences that contribute to formations of identity; second, by acting as a place for the expression of private or deviant emotions; third, by functioning as a barometer of wider cultural and attitudinal change; fourth, by serving as an engine of momentous historical change; and fifth, by working as a tool for emotional connection across communities, both within specific time periods but also across them. The introduction finishes by outlining how the special issue's five articles and review section address each of these categories, while also illustrating new methodological possibilities for the field.

History of the Study of Apocrypha in Early Medieval England

2020 ◽  
Vol 48 (3-4) ◽  
pp. 13-26
Author(s):  
Brandon W. Hawk
Keyword(s):  
Old Testament ◽  
Medieval England ◽  
Medieval Period ◽  
Early Medieval ◽  
Future Directions ◽  
Early Judaism ◽  
Wide Range ◽  
History Of ◽  
The Subject ◽  
Early English

Literature written in England between about 500 and 1100 CE attests to a wide range of traditions, although it is clear that Christian sources were the most influential. Biblical apocrypha feature prominently across this corpus of literature, as early English authors clearly relied on a range of extra-biblical texts and traditions related to works under the umbrella of what have been called “Old Testament Pseudepigrapha” and “New Testament/Christian Apocrypha." While scholars of pseudepigrapha and apocrypha have long trained their eyes upon literature from the first few centuries of early Judaism and early Christianity, the medieval period has much to offer. This article presents a survey of significant developments and key threads in the history of scholarship on apocrypha in early medieval England. My purpose is not to offer a comprehensive bibliography, but to highlight major studies that have focused on the transmission of specific apocrypha, contributed to knowledge about medieval uses of apocrypha, and shaped the field from the nineteenth century up to the present. Bringing together major publications on the subject presents a striking picture of the state of the field as well as future directions.

FROM THE HISTORY OF THE FORMATION AND DEVELOPMENT OF PERIODICALS IN NAMANGAN

2019 ◽  
Vol 20 (2) ◽  
pp. 49-54
Author(s):  
Dildora Alinazarova ◽  
Keyword(s):  
The Past ◽  
Wide Range ◽  
History Of ◽  
Printing House

In this article, based on an analysis of a wide range of sources, discusses the emergence and development of periodicals and printing house in Namangan. The activities of Ibrat- as the founder of the first printing house in Namangan are considered. In addition, it describes the functioning and development of "Matbaai Ishokia" in the past and present

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