This book contains the proceedings of a workshop on the Theoretical Founda­ tion for Large-Scale Computations of Nonlinear Material Behavior, held under the auspices of the National Science Foundation (NSF) and the Defense Advance Re­ search Projects Agency (DARPA), at Northwestern University, October 24-26, 1983. The main objective of this workshop was to provide a forum for the exchange of information and views on major issues relating to the fundamentals of character­ izing the inelastic constitutive material behavior. Comments on the Aims of the Workshop, by Drs. William Snowden and Thomas Bache, pp. 1-5, outline reasons for holding this workshop, and provide further background. The format of the workshop was designed to optimize the interaction between researchers whose primary interest is material characterization and numerical analysts whose primary interest is the development and practical use of large computer codes. The program of the workshop and a list of the workshop partic­ ipants are found at the end of these proceedings.

This book contains the proceedings of a workshop on the Theoretical Founda­ tion for Large-Scale Computations of Nonlinear Material Behavior, held under the auspices of the National Science Foundation (NSF) and the Defense Advance Re­ search Projects Agency (DARPA), at Northwestern University, October 24-26, 1983. The main objective of this workshop was to provide a forum for the exchange of information and views on major issues relating to the fundamentals of character­ izing the inelastic constitutive material behavior. Comments on the Aims of the Workshop, by Drs. William Snowden and Thomas Bache, pp. 1-5, outline reasons for holding this workshop, and provide further background. The format of the workshop was designed to optimize the interaction between researchers whose primary interest is material characterization and numerical analysts whose primary interest is the development and practical use of large computer codes. The program of the workshop and a list of the workshop partic­ ipants are found at the end of these proceedings.

Hydraulic fracturing has been and continues to be a major techno­ logical tool in oil and gas recovery, nuclear and other waste disposal, mining and particularly in-situ coal gasification, and, more recently, in geothermal heat recovery, particularly extracting heat from hot dry rock masses. The understanding of the fracture process under the ac­ tion of pressurized fluid at various temperatures is of fundamental scientific importance, which requires an adequate description of thermomechanical properties of subsurface rock, fluid-solid interaction effects, as well as degradation of the host rock due to temperature gradients introduced by heat extraction. Considerable progress has been made over the past several years in laboratory experiments, analytical and numerical modeling, and in-situ field studies in various aspects of hydraulic fracturing and geothermal energy extraction, by researchers in the United States and Japan and also elsewhere. However, the results have been scattered throughout the literature. Therefore, the time seemed ripe for bringing together selected researchers from the two countries, as well as observers from other countries, in order to survey the state of the art, exchange scientific information, and establish closer collaboration for further, better coordinated scientific effort in this important area of research and exploration.

This book contains the proceedings of a workshop on the Theoretical Founda­ tion for Large-Scale Computations of Nonlinear Material Behavior, held under the auspices of the National Science Foundation (NSF) and the Defense Advance Re­ search Projects Agency (DARPA), at Northwestern University, October 24-26, 1983. The main objective of this workshop was to provide a forum for the exchange of information and views on major issues relating to the fundamentals of character­ izing the inelastic constitutive material behavior. Comments on the Aims of the Workshop, by Drs. William Snowden and Thomas Bache, pp. 1-5, outline reasons for holding this workshop, and provide further background. The format of the workshop was designed to optimize the interaction between researchers whose primary interest is material characterization and numerical analysts whose primary interest is the development and practical use of large computer codes. The program of the workshop and a list of the workshop partic­ ipants are found at the end of these proceedings.

This book contains the proceedings of a workshop on the Theoretical Founda­ tion for Large-Scale Computations of Nonlinear Material Behavior, held under the auspices of the National Science Foundation (NSF) and the Defense Advance Re­ search Projects Agency (DARPA), at Northwestern University, October 24-26, 1983. The main objective of this workshop was to provide a forum for the exchange of information and views on major issues relating to the fundamentals of character­ izing the inelastic constitutive material behavior. Comments on the Aims of the Workshop, by Drs. William Snowden and Thomas Bache, pp. 1-5, outline reasons for holding this workshop, and provide further background. The format of the workshop was designed to optimize the interaction between researchers whose primary interest is material characterization and numerical analysts whose primary interest is the development and practical use of large computer codes. The program of the workshop and a list of the workshop partic­ ipants are found at the end of these proceedings.

Hydraulic fracturing has been and continues to be a major techno­ logical tool in oil and gas recovery, nuclear and other waste disposal, mining and particularly in-situ coal gasification, and, more recently, in geothermal heat recovery, particularly extracting heat from hot dry rock masses. The understanding of the fracture process under the ac­ tion of pressurized fluid at various temperatures is of fundamental scientific importance, which requires an adequate description of thermomechanical properties of subsurface rock, fluid-solid interaction effects, as well as degradation of the host rock due to temperature gradients introduced by heat extraction. Considerable progress has been made over the past several years in laboratory experiments, analytical and numerical modeling, and in-situ field studies in various aspects of hydraulic fracturing and geothermal energy extraction, by researchers in the United States and Japan and also elsewhere. However, the results have been scattered throughout the literature. Therefore, the time seemed ripe for bringing together selected researchers from the two countries, as well as observers from other countries, in order to survey the state of the art, exchange scientific information, and establish closer collaboration for further, better coordinated scientific effort in this important area of research and exploration.