Combined Release and Radiation Effects Satellite Time History Data Base

1991 ◽  
Author(s):  
Dennis E. Delorey
1987 ◽  
Vol 10 (5) ◽  
pp. 387-395 ◽  
Author(s):  
Stephen E. Jones ◽  
Thomas E. Moon ◽  
Gianni Bonadonna ◽  
Pinuccia Valagussa ◽  
Saul Rivkin ◽  
...  

2010 ◽  
Vol 37 (9) ◽  
pp. 1224-1231 ◽  
Author(s):  
Kate Deblois ◽  
Jean-Pascal Bilodeau ◽  
Guy Doré

This paper presents the results of an exploratory analysis of falling weight deflectometer (FWD) data collected on a large project about the spring thaw behaviour of pavements. The test site includes four test sections, two of which are conventional flexible pavement structures, whereas the other two are built with a cement-treated base. The aim of this study is to verify the applicability of using FWD time history data to evaluate damage to a road during the thawing period. The applicability of the analysis techniques is verified through the phase angle and dissipated energy. The data analyzed were obtained from tests conducted with an FWD on one flexible pavement test section. The results obtained showed a clear difference between the winter, thawing, and summer periods. It was found that the phase angle and dissipated energy can be used to evaluate the road damage during the thawing period through quantification of the phase angle and dissipated energy. These factors can also be used to describe the pavement behaviour in terms of elasticity and viscoelasticity.


1987 ◽  
Vol 10 (5) ◽  
pp. 396-403 ◽  
Author(s):  
Thomas E. Moon ◽  
Stephen E. Jones ◽  
Gianni Bonadonna ◽  
Pinuccia Valagussa ◽  
Trevor Powles ◽  
...  

2017 ◽  
Vol 13 (2) ◽  
pp. 120-124
Author(s):  
Jozef Komačka

Abstract A Falling Weight Deflectometer (FWD) represents one group of the devices used for diagnostics of pavement bearing capacity. Usually, the FWD dynamic load is substituted by a static load in the evaluation process to determine the equivalent modulus of a pavement structure or modulus of pavement layers. However, the data recorded during a bearing capacity test by FWD can be used to reveal the propagation of a dynamic impulse generated by FWD. It gives a possibility to use them in an evaluation method based on the propagation of waves generated by dynamic impulse. Therefore, the FWD time history data was assessed with regard to possible using in the method of the Spectral Analysis of Surface Waves. Basically, the possibility to determine the velocity of a generated surface wave was evaluated. It was found out the same deflection values exist at consecutive time intervals in the relevant part of the time history data (the arrival of the front of the wave or the area of maximum deflection value). Two methods were used to determine the exact time of the wave occurrence at receivers. It was concluded the differences between the used methods exist. It means the calculated velocities of a wave and shear modulus are also different. Importance of the shear modulus differences were estimated using the Slovak bearing capacity classification based on elastic modulus values. Taking into account the range of modulus in one classification class it can be stated the differences in the shear modulus determined according to used two methods could be very significant if the values calculated for short distance of the receiver are used. In the case of longer distance of the receivers the differences are not so high and significant.


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