Effect of Reduced Pressure on Thermal-expansion Behavior of Rocks and Its Significance to Thermal Fragmentation.
J Appl Phys 1970 Dec; 41(13):5147-5151
Thermal expansion is a significant parameter for the creation of thermal stresses to fragment rocks by heat. A method for experimentally measuring rock response to induced thermal stresses from cyclic thermal expansion of the rock surface is developed using strain-gage technique. Rock fracture caused by internal thermal stresses during heating and cooling in atmosphere and vacuum environment is examined. The response of rock material to induced thermal stresses is shown to be independent of reduced environmental pressure down to 15-5 torr. The results of reduced environmental pressure on thermal expansion behavior of some simulated lunar rocks are presented. These results provide a new insight on the feasibility of fragmenting the rock with thermal energy in vacuum environment.
J. Appl. Phys., V. 41, No. 13, December 1970, PP. 5147-5151