Accession Number:

ADA393288

Title:

Failure of Tank Track Pads, Investigation into the Technical Report for FY-79 and FY-80

Descriptive Note:

Final rept. Oct 1978-Oct 1980

Corporate Author:

LAWRENCE LIVERMORE NATIONAL LAB CA

Report Date:

1980-10-29

Pagination or Media Count:

137.0

Abstract:

This report describes a two-year study into the failure of tank track pads. Emphasis here is primarily on pads associated with the T-142 track. Temperature was recognized as an important parameter, and a thermal model has been developed which employs a finite element thermal analysis code at LLNL. The model involves a plane section of T-142 track and utilizes convective boundary conditions. The model does an excellent job of predicting temperature data obtained in the field on the T-142 track. The maximum predicted temperature at the center of the pad after 6,000 s 1.67 hr. of continuous operation is 132 deg C 270 deg F. The structural response of the pad to the loading provided by the tank has also been analyzed using a mechanical model which includes a section of T-142 track, a roadwheel, and supporting terrain. The output of the model has been presented in the form of stress contour plots showing the normal stress and effective stress generated in the pad. Field data relevant to the problem has been collected at the Yuma Proving Grounds. Surface and internal pad temperatures have been measured on an M-103 tank as a function of running time and pad manufacturer. Experimental work has also been done to assess crack growth, fatigue strength, and residual tear strength after fatigue. In addition, material properties required for the structural and thermal models were evaluated. We also examined the changes in physical properties and chemical characteristics brought about by running pads on a tank at the Yuma Proving Grounds. The thermal diffusivity was observed to decrease by about 20 due to field testing, while the tear strength decreased between 20 and 30 depending upon the terrain.

Subject Categories:

  • Combat Vehicles
  • Explosions
  • Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE