Assessment and Implications of Bulk Solid Springback Characteristics

摘要

This paper first describes the behaviour of bulk solids exhibiting spring back. In particular their behaviour during simple uniaxial load and unloading cycle and that occurring during shear testing is discussed. Second a procedure is then presented to predict the spring back generated stress or constraining stress as a function of the sample major consolidation stress. Thirdly the technique to adjust the 'as measured' Flow Function to determine the constant strain or springback adjusted Flow Function is then presented. The latter Flow Function can be confidently used to predict the necessary channel critical outlet dimension for reliable discharge. It is suggested that this procedure is sufficiently accurate for engineering purposes and avoids the need to access purpose built test shear cells. The significance of springback generated stresses in governing the critical outlet dimension of a low rank coal is highlighted by a design case study.