Influence of the Rise Time and Decay Time of Stress Wave on Spalling Process of Rock-Like Material

Abstract

Using numerical code RFPA2D (dynamic version), spallation processes of rock-like medium induced by reflection of stress wave with different rise time and decay time are simulated, and based on description and discussion on the failure area in the document [1], the influence of the rise time and decay time of stress wave on spalling process of rock-like material are numerically analyzed and discussed. Results indicate that the comminution zone is affected little by the duration of stress wave regardless of the rise time or decay time, and the fracture zone is affected to a greater extent by the rise time than the decay time, and the spalling zone is affected to some extent by the duration of stress wave regardless of the rise time or decay time, also, the stability of specimen is affected by the duration of stress wave regardless of the rise time or decay time, and the specimen loses stability at a certain decay time earlier than that at the same rise time. Furthermore, the effects of rise time and decay time on the number of failure elements are also investigated. Results show that a shorter rise and decay time increase the number of radial cracks. At longer rise time and decay time, the number of cracks is reduced and the cracks extend longer. In addition, the spalling increases to some extent as the rise time or decay time decreases.