Automated 3-D crack growth simulation

Abstract

Automated simulation of arbitrary, non-planar, 3-D crack growth in real-life engineered structures requires two key components: crack representation and crack growth mechanics. A model environment for representing the evolving 3-D crack geometry and for testing various crack growth mechanics is presented. Reference is made to a speci"c implementation of the model, called FRANC3D. Computational geometry and topology are used to represent the evolution of crack growth in a structure. Current 3-D crack growth mechanics are insu$cient; however, the model allows for the implementation of new mechanics. A speci"c numerical analysis program is not an intrinsic part of the model, i.e. "nite and boundary elements are both supported. For demonstration purposes, a 3-D hypersingular boundary element code is used for two example simulations. The simulations support the conclusion that automatic propagation of a 3-D crack in a real-life structure is feasible. Automated simulation lessens the tedious and time-consuming operations that are usually associated with crack growth analyses. Speci"cally, modi"cations to the geometry of the structure due to crack growth, remeshing of the modi"ed portion of the structure after crack growth and reapplication of boundary conditions proceeds without user intervention.

Spiral to flat fracture transition for notched rods under torsional loading

“…Other challenges arise from the complexity of implementing computational procedures for fracture surface evolution, such as remeshing of complex and evolving fracture surfaces (Carter et al 2000), phase field methods (Hakim and Karma 2009), cohesive zone models (Park et al 2012), atomistic (Coffman et al 2008), peridynamics (Youn and Bobaru 2010) and other discrete approaches.…”

Three-dimensional crack growth with hp-generalized finite element and face offsetting methods

“…Although Erdogan-Sih's [20] criterion considers only modes I and I I to predict the crack growth orientation, this criterion is broadly applied in three-dimensional simulations to provide the growth direction along the crack front. The works of Carter et al [8], Krysl et al [33] and Gravouil et al [26] are among the works that apply Erdogan-Sih's criterion for crack growth orientation in three-dimensional simulations. Figure 21 illustrates the results for the same inclined penny-shaped crack example presented in this Section with the crack growth methodology proposed in this paper but considering K I I I = 0 in Eqs.…”

“…• Otherwise, update crack front position using either PAE or PAS and break while loop. A similar sequence of steps is also performed in the research codes that use the standard FEM for fatigue crack growth assessment such as FRANC3D [8], ADAP-CRACK3D [61] and Zencrack [80]. The main difference is that, in this work, we explore the flexibility of the hp-GFEM to efficiently build accurate approximations at each crack step and evolve the crack surface without the mesh topology issues usually found in crack growth simulations with standard FEM [77].…”

Application of Particle Methods to Static Fracture of Reinforced Concrete Structures

“…The Cornell group of Ingraffea have developed remeshing to a high degree of robustness (see e.g. (Potyondy et al, 1995;Bittencourt et al, 1996;Carter et al, 2000)), but three dimensional problems with multiple cracks appear to be very challenging by these methods. Recently, discrete crack methods were developed where the crack can propagate arbitrary in an element without remeshing.…”