Roger D. Hart

Bio: Roger D. Hart is an academic researcher. The author has contributed to research in topics: Discrete element method & Rock mechanics. The author has an hindex of 5, co-authored 6 publications receiving 1222 citations.

Numerical modelling of discontinua

Abstract: Discrete element methods are numerical procedures for simulating the complete behaviour of systems of discrete, interacting bodies. Three important aspects of discrete element programs are examined: (1) the representation of contacts; (2) the representation of solid material; and (3) the scheme used to detect and revise the set of contacts. A proposal is made to define what constitutes a discrete element program, and four classes of such programs are described: the distinct element method, modal methods, discontinuous deformation analysis and the momentum‐exchange method. Several applications and examples are presented, and a list is given of suggestions for future developments.

Development of generalized 2-D and 3-D distinct element programs for modeling jointed rock

Abstract: : The capabilities of the UDEC computer program have been improved to provide full generality of the program for modeling jointed rock. Complete features exist for simulating variable rock deformability, nonlinear behavior of distinct joints and intact rock, dynamic cracking, projectile impaction, and fluid flow and fluid pressure generation in joints and voids. Further, the first stage in the development of a three-dimensional distinct element code has been completed. A new data structure has been designed and a test-bed code produced for three-dimensional analysis. Additional keywords: Computations; Rock mechanics; UDEC(Universal Distinct Element Code); Mathematical models.

9 – Numerical Modeling of Discontinua

Abstract: Publisher Summary This chapter focuses on numerical modeling of discontinua. It discusses the important aspects in the modeling of systems of discrete bodies—both physical and numerical aspects— and explains the diversity of applications. A discontinuous medium is distinguished from a continuous one by the existence of contacts or interfaces between the discrete bodies that comprise the system. An important component of any discrete element method is the formulation for representing contacts. In the direct method of introducing deformability, the body is divided into internal elements or boundary elements to increase the number of degrees of freedom. The possible complexity of deformation depends on the number of elements into which the body is divided. A complex deformation pattern can also be achieved in a body by the superposition of several mode shapes for the whole body. In the naive approach, each body is checked against every other body to determine if contact can occur. Many finite element, boundary element and Lagrangian finite difference programs have interface elements or slide lines that enable them to model a discontinuous material to some extent.

Numerical modelling of discontinua

Abstract: Discrete element methods are numerical procedures for simulating the complete behaviour of systems of discrete, interacting bodies. Three important aspects of discrete element programs are examined: (1) the representation of contacts; (2) the representation of solid material; and (3) the scheme used to detect and revise the set of contacts. A proposal is made to define what constitutes a discrete element program, and four classes of such programs are described: the distinct element method, modal methods, discontinuous deformation analysis and the momentum‐exchange method. Several applications and examples are presented, and a list is given of suggestions for future developments.