Abstract:Jump phenomenon is a representative nonlinear behavior of inclined cable. Although it has been discovered both in theory and experiment, jumping course is yet to be observed. An experiment was carried out to directly observe the jumping course and to ascertain nonlinear behaviors in this course. An automatic jump was directly observed by continuously repeat the sweep testing to make one of the excitation frequencies just right equal to the threshold frequency. Attributes of spatial motion during the jumping course were investigated. It is found that the spatial motion goes through three stages in the course, no merely sharp changes of the response amplitude as traditionally believed. These stages are: sharp changes of the response amplitude, dominative motion alternate between the out-of-plane and in-plane vibrations, and balloon motion alternate between the clockwise and anticlockwise directions.