A damaging beam-lattice model for quasi-brittle fracture

2022 ◽  
pp. 111404
Author(s):  
Margaux Sage ◽  
Jérémie Girardot ◽  
Jean-Benoît Kopp ◽  
Stéphane Morel
Keyword(s):  
Brittle Fracture ◽  
Lattice Model ◽  
Beam Lattice

3D Generalized Beam (GB) Lattice Model for Analysis of the Failure of Concrete

2013 ◽  
Vol 652-654 ◽  
pp. 1455-1465
Author(s):  
Han Wang ◽  
Ming Hao Zhao ◽  
Ji Gao ◽  
Guang Yuan Wang
Keyword(s):  
Lattice Model ◽  
Peak Load ◽  
Computational Effort ◽  
Numerical Results ◽  
Particle Content ◽  
Three Phase ◽  
3D Effects ◽  
Fracture Processes ◽  
Beam Lattice

Concrete is usually described as a three-phase material, where matrix, aggregate and interface zones are distinguished. The beam lattice model has been applied widely by many investigators to simulate fracture processes in concrete. Due to the extremely large computational effort, however, the beam lattice model faces practical difficulties. Moreover, real fracture processes are 3D and not 2D. In our investigation, a new 3D lattice called generalized beam (GB) lattice is developed to reduce computational effort. Numerical results obtained by the model are in agreement to what are observed in tests. The 3D effects of the particle content on the peak load and ductility are discussed as well as the 3D fracturing phenomenon.

A BEAM LATTICE MODEL TO INVESTIGATE BASIC ASPECTS OF BONE REMODELING

2012 ◽  
Vol 45 ◽  
pp. S116
Author(s):  
Davide Ruffoni ◽  
Manfred M. Maurer ◽  
Richard Weinkamer ◽  
Ralph Müller
Keyword(s):  
Bone Remodeling ◽  
Lattice Model ◽  
Beam Lattice

scholarly journals Discrete Lattice Model of Quasi-Brittle Fracture in Porous Graphite

2014 ◽  
Vol 3 (3) ◽  
pp. 20130077l ◽  
Author(s):  
Craig N. Morrison ◽  
Mingzhong Zhang ◽  
Andrey P. Jivkov ◽  
John R. Yates
Keyword(s):  
Brittle Fracture ◽  
Lattice Model ◽  
Porous Graphite

scholarly journals Study of Dynamic Brittle Fracture of Composite Lamina Using a Bond-Based Peridynamic Lattice Model

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Jushang Guo ◽  
Weicheng Gao ◽  
Zhenyu Liu ◽  
Xiongwu Yang ◽  
Fengshou Li
Keyword(s):  
Brittle Fracture ◽  
Lattice Model ◽  
Composite Laminates ◽  
Lattice Structure ◽  
Numerical Implementation ◽  
Energy Equivalence ◽  
Topological Lattice ◽  
Proposed Model ◽  
Dynamic Brittle Fracture ◽  
Orthogonal Anisotropy

We proposed a bond-based peridynamic lattice model for simulating dynamic brittle fracture of 2D composite lamina. Material orthogonal anisotropy was represented by rotating topological lattice structure instead of fiber directions. Analytical derivation and numerical implementation of the proposed model were given based on energy equivalence. Benchmark composite lamina tests are used to validate the capability of modeling dynamic fracture of the method. The peridynamic lattice model is found to be robust and successful in modeling dynamic brittle fracture of 2D composite lamina and can be extended to composite laminates by applying 3D lattice structure.

7-beam lattice images of (110) oriented Ge

1978 ◽  
Vol 36 (1) ◽  
pp. 290-291
Author(s):  
J.R. Parsons ◽  
C.W. Hoelke
Keyword(s):  
Image Features ◽  
Objective Lens ◽  
Lattice Plane ◽  
Lattice Image ◽  
Crystalline Defects ◽  
Transmission Electron ◽  
Lattice Images ◽  
Electron Microscopes ◽  
Structural Aspects ◽  
Beam Lattice

The direct imaging of a crystal lattice has intrigued electron microscopists for many years. What is of interest, of course, is the way in which defects perturb their atomic regularity. There are problems, however, when one wishes to relate aperiodic image features to structural aspects of crystalline defects. If the defect is inclined to the foil plane and if, as is the case with present 100 kV transmission electron microscopes, the objective lens is not perfect, then terminating fringes and fringe bending seen in the image cannot be related in a simple way to lattice plane geometry in the specimen (1).The purpose of the present work was to devise an experimental test which could be used to confirm, or not, the existence of a one-to-one correspondence between lattice image and specimen structure over the desired range of specimen spacings. Through a study of computed images the following test emerged.

Calculation of structure images of crystalline defects

1978 ◽  
Vol 36 (1) ◽  
pp. 282-283
Author(s):  
M.A. O'Keefe ◽  
Sumio Iijima
Keyword(s):  
Diffuse Scattering ◽  
Computing Time ◽  
Continuous Distribution ◽  
Sampling Interval ◽  
Reciprocal Space ◽  
Objective Lens ◽  
Lattice Images ◽  
Slice Method ◽  
Space Cell ◽  
Beam Lattice

We have extended the multi-slice method of computating many-beam lattice images of perfect crystals to calculations for imperfect crystals using the artificial superlattice approach. Electron waves scattered from faulted regions of crystals are distributed continuously in reciprocal space, and all these waves interact dynamically with each other to give diffuse scattering patterns.In the computation, this continuous distribution can be sampled only at a finite number of regularly spaced points in reciprocal space, and thus finer sampling gives an improved approximation. The larger cell also allows us to defocus the objective lens further before adjacent defect images overlap, producing spurious computational Fourier images. However, smaller cells allow us to sample the direct space cell more finely; since the two-dimensional arrays in our program are limited to 128X128 and the sampling interval shoud be less than 1/2Å (and preferably only 1/4Å), superlattice sizes are limited to 40 to 60Å. Apart from finding a compromis superlattice cell size, computing time must be conserved.

Point and planar defects in the iron sulfide compounds Fe1-xS

1984 ◽  
Vol 42 ◽  
pp. 434-435
Author(s):  
Thao A. Nguyen
Keyword(s):  
Low Temperatures ◽  
Direct Evidence ◽  
Iron Sulfide ◽  
Planar Defects ◽  
Selective Area ◽  
Vacancy Ordering ◽  
Different Types ◽  
Lattice Images ◽  
The Subject ◽  
Beam Lattice

It is well known that the large deviations from stoichiometry in iron sulfide compounds, Fe1-xS (0≤x≤0.125), are accommodated by iron vacancies which order and form superstructures at low temperatures. Although the ordering of the iron vacancies has been well established, the modes of vacancy ordering, hence superstructures, as a function of composition and temperature are still the subject of much controversy. This investigation gives direct evidence from many-beam lattice images of Fe1-xS that the 4C superstructure transforms into the 3C superstructure (Fig. 1) rather than the MC phase as previously suggested. Also observed are an intrinsic stacking fault in the sulfur sublattice and two different types of vacancy-ordering antiphase boundaries. Evidence from selective area optical diffractograms suggests that these planar defects complicate the diffraction pattern greatly.

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