Synthetic Vertical Acceleration Time Histories for High Speed Craft

2013 ◽  
Author(s):  
J M Hirst ◽  
◽  
S J C Dyne ◽  
T E Coe ◽  
◽  
...  
Keyword(s):  
High Speed ◽  
Vertical Acceleration ◽  
Acceleration Time ◽  
Acceleration Time Histories ◽  
Time Histories

Pilot and Observer Performance in Simulated Low Altitude High Speed Flight

1965 ◽  
Vol 7 (3) ◽  
pp. 257-265 ◽  
Author(s):  
Ben Schohan ◽  
Harve E. Rawson ◽  
Stanley M. Soliday
Keyword(s):  
Atmospheric Turbulence ◽  
High Speed ◽  
Target Identification ◽  
Observer Performance ◽  
Acceleration Time ◽  
Acceleration Time Histories ◽  
Time Histories ◽  
Low Altitude ◽  
Vertical Accelerations

Responses of experienced pilots and aerial observers were studied in simulated low-altitude, high-speed (LAHS) flight. The pilots “flew” three-hour surveillance missions at airspeeds of .4M and .9M in different degrees of simulated atmospheric turbulence. Flying ability decreased from .4 to .9M; however, intensity of vertical accelerations did not seem to affect flying ability except at the most severe levels. Target identification was unimpaired by either turbulence or airspeed. The observers also flew three-hour missions while experiencing acceleration time histories recorded from the pilot's flights. Target identification deteriorated as airspeed increased from 0.4 to 0.9 Mach. Gust intensity did not affect performance of any of their tasks. Performance efficiency on all tasks did not deteriorate from beginning to end of the missions of both pilots and observers.

scholarly journals The Effect of the Vertical Acceleration on Stability Assessment of Seismically Loaded Earth Dams

2016 ◽  
Vol 63 (2-3) ◽  
pp. 101-120 ◽  
Author(s):  
Aleksandra Korzec
Keyword(s):  
Slope Stability ◽  
Vertical Component ◽  
Vertical Acceleration ◽  
Permanent Displacement ◽  
Ground Acceleration ◽  
Safety Criterion ◽  
Acceleration Time ◽  
Acceleration Time Histories ◽  
Time Histories ◽  
Block Approach

AbstractIn the assessment of slope stability, the vertical component of acceleration is commonly neglected. However, signal analyses performed on a large number of acceleration time histories have revealed that the vertical peak ground acceleration can be as high as the horizontal one. In this paper, a method of slope stability analysis regarding the vertical component of acceleration is proposed. It considers a rigid body system affected by the acceleration time histories in both horizontal and vertical directions. In a general case, the strength of the contact between acceleration components is time dependent. Parametric analysis was performed on the basis of cyclic harmonic loading, assuming a safety criterion in the form of permanent displacement. The results, for both harmonic and real acceleration time histories, were compared with the results of the commonly used Newmark’s sliding block approach, which revealed significant differences in permanent displacements calculated by the two methods.

Metrics for the Comparison of Acceleration Time Histories

2017 ◽  
Author(s):  
Nithyagopal Goswami ◽  
Mourad Zeghal ◽  
Majid Manzari ◽  
Bruce Kutter
Keyword(s):  
Acceleration Time ◽  
Acceleration Time Histories ◽  
Time Histories

Selection and Scaling Time History Records for Performance-Based Design

2017 ◽  
pp. 1-35
Author(s):  
Yasin M. Fahjan ◽  
F. İlknur Kara ◽  
Aydın Mert
Keyword(s):  
Ground Motion ◽  
Strong Ground Motion ◽  
Time History ◽  
Design Code ◽  
Uniform Hazard Spectra ◽  
Acceleration Time ◽  
Acceleration Time Histories ◽  
Recent Developments ◽  
Time Histories ◽  
Strong Ground

Recent developments in performance-based analyses and the high performance of computational facilities have led to an increased trend for utilizing nonlinear time-history analysis in seismic evaluation of the performance of structures. One of the crucial issues of such analysis is the selection of appropriate acceleration time histories set that satisfy design code requirements at a specific site. In literature, there are three sources of acceleration time histories: 1) recorded accelerograms in real earthquakes scaled to match design code spectrum/uniform hazard spectra/conditional mean spectrum, 2) artificial records generated from white noise spectra to satisfy design code spectrum, and 3) synthetic records obtained from seismological models. Due to the increase of available strong ground motion database, using and scaling real recorded accelerograms is becoming one of the most contemporary research issues in this field. In this study, basic methodologies and criteria for selecting strong ground motion time histories are discussed. Design code requirements for scaling are summarized for ASCE/SEI-7-10, EC8 and Turkish Seismic Codes. Examples for scaling earthquake records to uniform hazard spectra are provided.

scholarly journals Development of two components acceleration time histories for Semarang, Indonesia, due to Semarang fault earthquake scenarios using 30 meters soil deposit model

2018 ◽  
Vol 159 ◽  
pp. 01043
Author(s):  
Windu Partono
Keyword(s):  
Site Response ◽  
Historical Earthquakes ◽  
Structure Design ◽  
Site Response Analysis ◽  
Response Analysis ◽  
Acceleration Time ◽  
Earthquake Scenarios ◽  
Acceleration Time Histories ◽  
Time Histories ◽  
Deposit Model

Development of surface acceleration time histories is important for dynamic analysis of structure design and evaluation. Acceleration time histories usually developed from seismograph records due to specific earthquake event. Following the research conducted by Team for Revision of Seismic Hazard Maps of Indonesia 2010 and 2016, Lasem fault and Semarang fault are two closest and dangerous shallow crustal fault earthquake sources which must be taken into account for seismic mitigation of Semarang. This paper presents the development two components surface acceleration time histories for Semarang caused by Semarang fault earthquake scenarios, with magnitude from 6 Mw to 7 Mw and maximum epicentre distance 15 Km. This research was performed by conducting deterministic hazard analysis, response spectral matching and site response analysis to obtain a pair of modified acceleration time histories. Site response analysis was performed by conducting 30 meters soil deposit model by taking the assumption that the position of bedrock elevation is 30 meters below the surface layer. Modified acceleration time histories were developed from a pair time histories (North-South/NS and East-West/EW direction) collected from worldwide historical earthquakes. Modified time histories were developed due to limited time histories data caused by Semarang fault earthquake source.

Development of Target Power Spectral Density Functions Compatible With Design Response Spectra

2015 ◽  
Author(s):  
Jinsuo R. Nie ◽  
Jim Xu ◽  
Joseph I. Braverman
Keyword(s):  
Spectral Density ◽  
Power Spectral Density ◽  
Seismic Analysis ◽  
General Procedure ◽  
Response Spectra ◽  
Acceleration Time ◽  
Power Spectral ◽  
Acceleration Time Histories ◽  
Time Histories ◽  
Spectral Shapes

For seismic analysis of nuclear structures, synthetic acceleration time histories are often required and are generated to envelop design response spectra following the U.S. Nuclear Regulatory Commission, Standard Review Plan (SRP) Section 3.7.1. It has been recognized that without an additional check of the power spectral density (PSD) functions, spectral matching alone may not ensure that synthetic acceleration time histories have adequate power over the frequency range of interest. The SRP Section 3.7.1 Appendix A provides a target PSD function for the Regulatory Guide 1.60 horizontal spectral shape. For other spectral shapes, additional guidance on developing the target PSD functions compatible with the design spectra is desired. This paper presents a general procedure for the development of target PSD functions for any practical design response spectral shapes, which has been incorporated into the recent SRP 3.7.1, Revision 4.

Shock Absorbing Characteristics of Floors Used for Dance Exercise

1988 ◽  
Vol 4 (3) ◽  
pp. 282-305 ◽  
Author(s):  
Peter R. Francis ◽  
Michael Leigh ◽  
Aldis Berzins
Keyword(s):  
Standardized Test ◽  
Test Method ◽  
Complex Nature ◽  
Data Sets ◽  
Acceleration Time ◽  
Testing Procedures ◽  
Acceleration Time Histories ◽  
Time Histories ◽  
Additional Procedure

The Standardized Test Method for Shock-Absorbing Properties of Playing Surface Systems and Materials (ASTM F-355) was used to evaluate the shock absorbing characteristics of 13 floors used for dance exercise. Acceleration-time histories indicated that the floors differed markedly in their shock absorbing behavior. The complex nature of the acceleration-time histories led to the conclusion that descriptors that have previously been used to quantify shock absorbing data were inadequate for the floors examined in this investigation. An additional procedure was devised in order to examine potentially injurious stresses on a performer while executing a common dance exercise movement performed on each of the 13 floors tested. It was concluded that the two testing procedures evaluated differing aspects of the shock absorbing mechanisms involved in dance exercise. However, a tentative relationship between the two corresponding data sets provided some support for the retention of ASTM F-355 as a reproducible test for the shock absorbing characteristics of floors.

Vertical Motion Inputs for Seismic Analysis of Large Span Bridge

2013 ◽  
Vol 275-277 ◽  
pp. 1403-1406
Author(s):  
Zheng Ru Tao ◽  
Xia Xin Tao
Keyword(s):  
Seismic Analysis ◽  
Three Dimensional ◽  
Low Frequency ◽  
Vertical Motion ◽  
Vertical Acceleration ◽  
Motion Field ◽  
Large Span ◽  
Acceleration Time Histories ◽  
Time Histories ◽  
Main Girder

In seismic analysis of large span bridge, inconsistent ground motions in three directions, lengthwise, lateral and vertical are required to input at the base of each of the two main girder piers. In order to adopt synthesized motion field for the inputs, a simple way to prepare the vertical motion is introduced for improvisation at this moment in this paper, since the synthesis in general consists of two parts, the low frequency ground motion calculated by a numerical method, like FEM, and the high frequency motion synthesized by random approach, and the result of the former is in three dimensional, while that of the latter has just horizontal component. The vertical acceleration time histories proposed in the paper show the way is available.

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