Numerical Investigation On The Dynamic Response Of Rock And Steel Structures Under Impact Loading

This thesis investigates the fluid-solid coupling problem under impact loads. Using the total variation diminishing scheme to solve the Euler equations, the numerical solutions of the explosive flow fields were obtained, while the numerical solutions concerned with the solid body response were obtained by the constant-parameter finite element method in the Lagrange coordinate system with respect to the spurious-work principle. On the basis of the present simulator, focusing on the impact loads, the computational subroutines for the elastico-plastic constitution and the rock constitution were inserted, and the elemental invalidation method used in the LS_DYNA software was introduced in the present simulator, in order to realize the finite element simulation of the fractural problem so that the present simulator has the preliminary function of simulating the propagation of stress waves and the spreading of the cracks. Choosing the spreading of elastico-plastic waves In a long pole and the dynamic extension of cracks at different inclined angles in thin plate as the research problems, this thesis validates the calculation method and the computational simulator, then conducts the numerical studies of the fluid-solid coupling problems, where, the premixed hydrogen-air mixture deflagration was occurred in a component imbedded pipe, and the working process of the single shoot of hole-pellet in an underground oil-well.The contents of this paper can be briefly described below:(1) The introduction of the research background, the corresponding advancement and the primary contents of the thesis was given in the first Chapter.(2) The description of the governing equations, numerical methods, and solution conditions was shown in the second Chapter.(3) In the third Chapter, the elastico-plastic and rock constitutions were described and the treatment of the numerical application of these constitutions was introduced, with the brief introduction of the break criterion and the element invalidation method.(4) In the fourth Chapter, the stress propagation and the cracks at different inclined angles in a long pole were chosen as sample problems to validate the numerical method and the calculation simulator.(5) In fifth Chapter, the shock wave impact related, and typical fluid-solid coupling problems were solved.â‘ The premixed hydrogen-air mixture was filled and ignited in an component-imbedded pipe to generate shock waves after deflagration, the process of the dynamic response concerned with the interaction between the explosive flow fields and shock waves and the pre-imbedded component and the pipe was numerically calculated.â‘¡Focus on the single shoot of hole pellet in an underground oil well, high pressure and temperature gas can be generated after ignition, numerical simulation was carried out for the process of interaction between the shock waves and the steel pipe and the rock (hole shooting).