Full-scale tests of vehicles influencing guardrail or median barrier systems involve complex dynamic mechanisms that are extremely difficult to characterize analytically. Thus, satisfactory theoretical values of the vehicle kinematics cannot be determined for correlating results obtained by experimental means. This abridgment concerns the results of a simple experimental test by which these theoretical quantities were established. Experimental data were collected by means of high-speed photography and acelerometers in the same manner as that used in the full-scale tests, and the results of the two techniques are compared with theoretical values. It has been shown by means of a simple test how the data-acquisition techniques of high-speed photography and accelerometer readings compare with theoretical values. It had been assumed that the differentiation of cine data would not be as accurate as integration of accelerometer data for the desired kinematic quantities. However, this was not the case, and it can be concluded from this study that the cine data will yield results that are just as accurate as, and probably more accurate than, the accelerometer data. Of course, considerably more instrumentation is neceassary for retrieval of the accelerometer data and can present undesirable sources of instrument error. Furthermore, inital conditions must be known in the integration process, and the instantaneous direction must be determined if the motion is curvilinear. The high-speed cine retrieval has the advantages of greater simplicity and the self-starting characteristic, but are must be exercised in the differentiation of the data. The errors caused by differentiation of curve fits near the ends of the sampled data can be made less significant if the period of interest can be bracketed on both ends by the data sampling. /Author/

Media Info

  • Features: Figures;
  • Pagination: p. 13-15
  • Monograph Title: Roadside safety appurtenances
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00196613
  • Record Type: Publication
  • ISBN: 0309028248
  • Report/Paper Numbers: HS-026 748
  • Files: TRIS, TRB
  • Created Date: Aug 28 1979 12:00AM