It is an explicit finite difference code for solving a variety of nonlinear problems in solid, fluid, and gas dynamics.
Solve Waves Center Crack Propagation ByShow citation Numerical Study on Crack Propagation by Using Softening Model under Blasting Rong Hu, 1 Zheming Zhu, 1 Jun Xie, 1 and Dingjun Xiao 1, 2 1 College of Architecture and Environment, Sichuan University, Chengdu, Sichuan 610065, China 2 College of Environment and Resources, Southwest University of Science and Technology, Mianyang, Sichuan 621010, China Show more Academic Editor: Cristina Leonelli Received 12 Apr 2015 Revised 16 Jul 2015 Accepted 21 Jul 2015 Published 02 Aug 2015 Abstract A mixed failure criterion, which combined the modified maximum principal stress criterion with the damage model of tensile crack softening, was developed to simulate crack propagation of rock under blasting loads.
Solve Waves Center Code For SolvingIn order to validate the proposed model, a set of blasting models with a crack and a borehole with different incident angles with the crack were established. By using this model, the property of crack propagation was investigated. ![]() In order to validate the numerical simulation results, experiments by using PMMA (polymethyl methacrylate) with a crack and a borehole were carried out. The charge structure and incident angle of the blasting experimental model were the same as those in the numerical models. The experiment results agree with the numerical simulation results. Introduction Blasting is an economic and efficient excavation method and is widely used in engineering of quarrying, mining, and tunnel excavation. Solve Waves Center Cracked Rock MassThe propagation of blasting-induced stress wave in cracked rock mass would introduce crack expansion and failure, which would possibly induce destructively geologic hazards, such as rock burst and slope slump. ![]() It is an important topic in rock dynamics and relevant disciplines to study the way cracks propagate under dynamic loading so as to know how the wing cracks develop at crack tips 1 as the case in static compressive loading, which has been well investigated by using complex function method 2 5. This research helps with predicting the dynamic strength and structural stability of cracked rock mass and provides theoretical basis for blasting design, improving blasting efficiency. The time taken by the explosive loading is extremely short, ranging, usually, from a couple of microseconds to dozens of microseconds. That renders the recording of the whole physical field impossible experimentally, whereas the state of the field can be described by means of numerical simulation, which is less expensive, and can be easily realized. However, the numerical simulation accuracy depends largely on the quality of the numerical model employed. Hence, a combined use of numerical simulation and experiment was carried out in this paper. In the numerical study, Preece and Thorne 6 used 3D finite element techniques and a damage constitutive model to study the detonation timing and fragmentation. Donz et al. 7 applied a model based on the discrete element to investigate the importance of stress waves on the initiation and propagation of radial fractures during the dynamic loading phase of explosion. By using UEDC code, Chen and Zhao 8 have simulated blasting wave propagation in joint rock mass. Using AUTODYN code and the modified maximum principal stress, Zhu et al. However, brittle materials, such as rock, act in inelastic way, which is caused by the nucleation, propagation, and connection of microcracks. Softening models are often used to describe the inelasticity of brittle material 13, 14. In this paper, the softening model applied is a function of fracture energy, plastic strain, and the grid size, and it can limit the results of the calculation of grid sensitivity to a certain extent. In experimental study, Rossmanith et al. PMMA is similar to that of rock under dynamic loading. The dynamic fracture mechanism of it has been widely studied by researchers 18 20. A numerical code, AUTODYN 21, 22, is applied in this study.
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