Showing papers on "Skyline published in 1989"

The dynamic behavior of a cable logging skyline and its effects on the tailspar

Abstract: Approved: Harold I. Laursen Initially, a small experimental study was undertaken to examine the influence of incline on the frequency of taut cables. The experiments consisted of exciting a short cable at angles of incline from zero to 90 degrees and at various tensions. The results from these experiments shows a small effect due to the incline as the cable approaches the vertical. However, this influence is small enough that the theoretical equation for the frequencies of a horizontal cable could be used to determine the frequencies of a taut, inclined cable. A computer model intended to simulate the dynamic behavior of a cable logging system skyline is the main thrust of this paper. In developing the computer model both finite element and finite difference methods were considered. The finite difference method was selected based on its efficiency in achieving the desired solution. A nine point implicit finite difference scheme, which guarantees stability of the solution, was employed. Computer model output for skyline frequencies and tensions were compared with a number of field tests. The results were encouraging and indicated the model to be reliable in simulating the dynamic behavior of a skyline with a log load. This information can be used to determine the influence of dynamic skyline behavior on loads experienced by the tailspar. The Dynamic Behavior of a Cable Logging Skyline and its Effect on the Tailspar by Kevin C. Womnack A THESIS submitted to Oregon State University in partial fulfillment of the requirements for the degree of Doctor of Philosophy Completed June 6, 1989 Commencement June 1990