DYNAMICS OF GUARDRAIL SYSTEMS

HIGHWAY-GUARDRAIL SYSTEMS ARE BEING INVESTIGATED BY MEANS OF DYNAMIC ANALYSIS AND SMALL-SCALE LABORATORY MODELS TO OBTAIN A BETTER UNDERSTANDING OF THE DYNAMIC INTERACTION OF THE VEHICLE AND THE GUARDRAIL STRUCTURE AND FROM THIS A MORE COMPLETE BASIS FOR DESIGN. THIS PAPER IS A FIRST REPORT ON THE PROGRESS OF THE INVESTIGATION AND INCLUDES: A GENERAL DISCUSSION OF THE VARIABLES; THE DIFFERENTIAL EQUATIONS OF MOTION OF THE VEHICLE IN CONTACT WITH THE GUARDRAIL; A DERIVATION OF THE LENGTH, FORCE, AND TIME SCALES FOR THE MODEL; THE CONSTRUCTION OF THE FIRST MODEL AND ITS RELATION TO A DEFINITE FULL-SCALE VEHICLE AND GUARDRAIL; AND THE LABORATORY METHODS, INCLUDING THE ADAPTATION OF MULTIPLE-FLASH STILL PHOTOGRAPHY TO THE RECORDING OF THE PATH OF THE VEHICLE AND TRANSVERSE DISPLACEMENTS OF THE GUARDRAIL. IT IS POSSIBLE TO INVESTIGATE A WIDE RANGE OF CONDITIONS OF DESIGN AND OPERATION BY THE USE OF A CONTROLLED LABORATORY MODEL. /AUTHOR/