基于有限幅度法的岩石高温损伤试验研究

he main objective of this study is to develop a damage assessment method for sandstone materials. Damage of moderately weathered granite subjected to different heating level is estimated by finite amplitude method of nonlinear ultrasonic in conjunction with two typical linear methods i.e. ultrasonic pulse velocity method and dynamic elastic modulus method. A damage index B which is based on nonlinear parameter β defined in nonlinear ultrasonic theory is proposed in this study. By comparing the results of nonlinear and linear parameters measured for different damage of sandstones, it is found that damage index B is more sensitive to the damage occurrence and development in sandstones and nonlinear ultrasonic techniques may be a better method in damage assessment of rock materials.