Effect of fine particles on the flow behavior ofpolycrystalline ice and glaciers——(Ⅰ) a dislocationbased relaxation model
微粒对多晶冰及冰川流变行为的影响——(Ⅰ) 基于位错的弛豫模型

A dislocation-based nonlinear relaxation model has been developed to quantify the variations of dislocation density in ice and glaciers as a function of flow stress during flow processes.The calculation based on the model indicates that during the power-law creep stage,the stress/strain hysteresis loop width and area increase linearly with the creep stress,and dislocation density increases as a second-power with the creep stress;while during the linear creep stage,the stress/strain hysteresis loop width,area and dislocation density remain constant.