Vehicle Structure Optimization for Crash Pulse

2004 ◽  
Author(s):  
Lei Gu ◽  
T. Tyan ◽  
G. Li ◽  
R. J. Yang
Keyword(s):  
Design Optimization ◽  
Response Surface ◽  
Time History ◽  
Structure Design ◽  
Time Interval ◽  
Vehicle Structure ◽  
Occupant Injury ◽  
Data Points ◽  
Vehicle Motion ◽  
Occupant Kinematics

In vehicle safety engineering, it is important to determine the severity of occupant injury during a crash. Computer simulations are widely used to study how occupants move in a crash, what they collide during the crash and thus how they are injured. The vehicle motion is typically defined for the occupant simulation by specifying a crash pulse. Many computer models used to analyze occupant kinematics do not calculate both vehicle motion and occupant motion at the same time. This paper presents a framework of response surface methodology for the crash pulse prediction and vehicle structure design optimization. The process is composed of running simulation at DOE sampling data points, generating surrogate models (response surface models), performing sensitivity analysis and structure design optimization for time history data (e.g., crash pulse). Within this framework, the engineer can perform DOE sampling, surrogate modeling, main effect plot within any time interval, and design optimization. Some recent applications are presented to demonstrate how these approaches are employed for a vehicle structure design.

Seismic Time History Data Precision and Time Interval Requirement

2020 ◽  
Author(s):  
Dali Li
Keyword(s):  
Response Spectrum ◽  
Total Duration ◽  
Time History ◽  
Response Spectra ◽  
Design Parameters ◽  
Time Interval ◽  
Nyquist Frequency ◽  
Frequency Range ◽  
History Data ◽  
Data Points

Abstract This paper provides the seismic time history data precision and time interval requirement for seismic dynamic analysis. U.S.NRC SRP 3.7.1 “Seismic Design Parameters” Acceptance Criteria for Design Time Histories specifies the power spectral density Nyquist Frequency, time interval, and total duration; however, it does not have the requirement for Response Spectra. The response spectrum bandwidth is inverse-proportional to time interval of the time history. For the time interval of 0.005 seconds, the bandwidth for the response spectrum is between 0.194 Hz and 80.5 Hz; the PSD Nyquist frequency is 100 Hz. For 20.48 seconds time history, 4096 data points are required. The response spectrum between 1.28 Hz and 13.6 Hz has the peak flat magnitude value; the magnitude drops to 0.707 of the peak value from 1.28 Hz to 0.194 Hz and from 13.6 Hz to 80.5 Hz. This paper also provides the time interval requirement for various response spectrum peak flat magnitude value; i.e., the response spectrum highest flat magnitude of 27.2 Hz requires a time interval of 0.0025 seconds time history. For 20.48 seconds time history, 8192 data points are required. For CSDRS, the time interval of 0.005 seconds is adequate for the frequency range of interest between 0.36 Hz and 57.2 Hz. For HRHF, the time interval of 0.0025 seconds is required to analyze the frequency range of interest between 0.36 Hz and 114.4 Hz.

scholarly journals Support structure design for New Zealand Forest Products Ltd's No. 5 Recovery Boiler

1987 ◽  
Vol 20 (1) ◽  
pp. 2-6
Author(s):  
R. D. Sharpe
Keyword(s):  
New Zealand ◽  
Seismic Performance ◽  
Time History ◽  
Forest Products ◽  
Structure Design ◽  
Seismic Resistance ◽  
Simple Application ◽  
Major Earthquake ◽  
Lateral Forces ◽  
Industrial Boilers

Internationally, the seismic resistance of large industrial boilers appears to be addressed by the most simple application of relatively low equivalent static lateral forces which are resisted elastically. This paper describes measures taken to ensure a predictable
and controlled seismic performance of such a boiler
during a major earthquake. Inelastic time-history methods of analysis were used to confirm that the desired performance would be achieved. As a result the client was able to purchase a relatively standard boiler in the international marketplace and still achieve a level of seismic resistance consistent with the best NZ practices.

scholarly journals Solar, ionospheric and geomagnetic indices

1998 ◽  
Vol 41 (5-6) ◽  
Author(s):  
L. Perrone ◽  
G. De Franceschi
Keyword(s):  
Time History ◽  
The Internet ◽  
Time Interval ◽  
Geomagnetic Indices

The most common solar, ionospheric and geomagnetic indices are here presented with particular reference to their application for radiocommunication prediction purposes. Summary tables of practical use are also included concerning the method of derivation of the indices, their time interval, their drawbacks, their time-history and the INTERNET node addresses where they are available.

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