Determination of Trailer Stability Through Simple Analytical Methods and Test Procedures

This paper provides approximate factors, measurement techniques, and test procedures that can be used to determine trailer stability. The recommended performance metric is damping ratio, or an equivalent cycle to half amplitude which is evaluated, via a pulse-steer procedure, at some reference speed. A minimum damping ratio criteria of 0.15 at 55 mph is suggested and compared to the results of recent full scale tests. The approach is useful in selecting a minimum value of hitch load (for various weight tow cars) that will insure a minimum acceptable level of trailer stability at highway speeds.