Method for solving nonlinear mechanics problem of continuous medium member by applying three-dimensional discrete entity

Abstract

The invention discloses a method for solving a nonlinear mechanics problem of a continuous medium member by applying a three-dimensional discrete entity. For the limitation of a conventional discrete unit method for calculating a continuous medium problem, discrete element models of two three-dimensional discrete entities are built by taking energy equivalence as a principle based on a mechanics theory of a continuous medium; by adding a contact spring between particle units, the Poisson ratio effect of a material is reflected; and an analytic relationship between a mesoscopic model parameter (spring stiffness) and macroscopic elastic constants (an elastic modulus and a Poisson ratio) is derived, so that a great breakthrough is achieved in simulation of the continuous medium with a large Poisson ratio in PFC software. In addition, a plastic part is added in a contact constitutive equation between the particle units. According to the method, the elastic-plastic problem of the continuous medium can be effectively subjected to simulative calculation analysis by adopting a discrete entity unit method; and the method is suitable for nonlinear mechanics problems of large deformation, damage fracture, collapse destruction and the like of a structure or the member.

Description

technical field [0001] The invention relates to a three-dimensional discrete element calculation and simulation method, in particular to a three-dimensional discrete solid element method for simulating continuous media, which is used to solve nonlinear mechanical problems such as large deformation, damage, fracture, and collapse of structures or components, and belongs to limited The field of meta-analysis techniques. Background technique [0002] The traditional finite element method has some difficulties in simulating steel structures, such as fabricated nodes: contact pairs need to be set for the surface-to-surface contact between bolts and nodes, stress concentration is likely to occur at the bolts during the actual loading process, and mesh division during simulation When densification is required, large deformation of the rod will lead to non-convergence and fracture. Therefore, it is necessary to find new numerical analysis methods. [0003] Since the discrete eleme...

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Problems solved by technology

However, the calculation accuracy of the traditional discrete element method is far inferior to that of the finite element method when calculating the continuum problem, and the parameters reflecting the force relationship of the unit often need to be determined through experiments, which seriously restricts the application of the discrete element method.

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