Numerical Simulation Of Rock Constitutive Relation Based On Virtual International Bond Model

With the development of rock engineering, more and more engineering projects arise in the world. The rock engineering’s geological disasters have also occurred, such as not only rock burst, the cavern collapsed, but also landslide, deformation, which is a serious threat to people’s life and property safety. Rock is a kind of complex products which generate by long geological movement and a typical quasi brittle engineering material and consist of defects. In all, rock is a homogeneous, discontinuous and complex material. Because of rock’s complex mechanics properties make the rock failure process is a complex evolution process with unbalanced and nonlinear. Therefore, evaluate the rock engineering’s state of security and stability, understand the support measures of positive and reasonable, research the constitutive relations of different rocks are of great significance theoretical meanings and even of important value engineering projects.(1) The thesis researches the domestic and foreign scholars devote to studying the numerical simulation of the whole process stress-strain curve, then choose VIB model as constitutive relation model, and in this paper from many aspects to introduce VIB model, such as theoretical background, basic idea, function equation and widely application, etc.(2) As the different formations of rock in the nature, selects the typical rock as red sandstone of sedimentary rocks and marble of metamorphic rocks as samples for test. Referring to the requirements of International Society of Rock Mechanics(ISRM) to make the rock specimens, which are under different loads carried out the uni-axial compressive strength tests and tri-axial compressive strength tests. Then introduce the influence of heterogeneity coefficient β, which is make a significant effect on the rock material’s constitutive relation under various confining pressures.(3) By the VIB model to realize the finite element numerical simulation and with Fortran software programming to calculate numerical model, then use Matlab software processing platform to build a multi-scale numerical simulation platform based on VIB model, finally obtains the two-dimensional stress-strain curve under different loading, also including three-dimensional whole process stress-strain curve. Take MTS-150-b experimental system rock mechanics and MTS815.03 electric servo rock mechanics to complete the whole process stress-strain curve for physical test. In comparison with the results, the VIB model can simulate different kinds of rock samples to get the whole process stress-strain curve which can match to the results of physical test. It proved that the application of VIB model to research the rocks’ constitutive relation is effective.In all, VIB model is not only expand the wide application scope, but also provide a new idea for the research of rock constitutive equation, make people know more about the constitutive relation of rock. The research of rock mechanics engineering acquires great theoretical meaning and practical significance.