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Thermal-mechanical methods of fragmenting rock were investigated to determine their feasibility and to evaluate parameters for possible application of such processes. Theories of temperature distribution and thermoelastic stresses were applied where possible. Most equations involving temperature dependent properties, moving heat sources, and more than one dimension are not susceptible to solution or to mathematical evaluation. The current theory of indentors was extended by means of the theory of plasticity to include factors such as bit shape and friction between the bit and rock. Application of a modified equation for the Rittinger crushing theory based upon surface energy particle size relationships was found to be useful in evaluating the surface energy for thermal-mechanical fragmentation.

Various tests were performed to determine the capabilities and limits of piezoresistive accelerometers. Macroscopic, static, and dynamic tests were conducted on all accelerometers before and after the environmental tests (electrical, humidity, and temperature). The accelerometers were overranged to check their overrange performance characteristics.