Crosswise tensile resistance of masonry patterns due to contact friction

The presented research focuses on masonry shells with dry (cohesionless) contacts. In the mechanical analysis of such structures, the material is often assumed to have zero resistance to tension. This simplification can be questioned in light of the fact that due to the frictional resistance between masonry layers compressed to each other, significant tension can be carried perpendicularly to the direction of the compression. The effect can be so considerable that the typical orange-slice cracking of masonry domes can be prevented purely by choosing a suitable brick shape and bond pattern. Based on preliminary 3DEC discrete element simulations with realistic and experimentally validated material parameters in order to understand the failure modes, the phenomenon is quantified in the present paper for the two main types of bond patterns applied in masonry shells: (i) different versions of the running bond pattern, and (ii) two versions of the herringbone pattern. The theoretically predicted failure tensile stresses are checked and validated with 3DEC discrete element simulations.

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A reply to the discussion on a calibration methodology to obtain material parameters for the representation of fracture mechanics based on discrete element simulations

Computers and Geotechnics ◽

10.1016/j.compgeo.2017.03.011 ◽

2017 ◽

Vol 86 ◽

pp. 249-251

Author(s):

Somayeh Behraftar ◽

Sergio Galindo Torres ◽

Alexander Scheuermann ◽

David J. Williams ◽

Eduardoantonio G. Marques ◽

...

Keyword(s):

Fracture Mechanics ◽

Discrete Element ◽

Material Parameters ◽

Discrete Element Simulations

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Mechanical Analysis of Fracturing String with Double Packers in Horizontal Well

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.325-326.800 ◽

2013 ◽

Vol 325-326 ◽

pp. 800-803

Author(s):

Zhi Miao Li ◽

Qian Bei Yue ◽

Ju Bao Liu

Keyword(s):

Horizontal Well ◽

Reaction Force ◽

Frictional Resistance ◽

Mechanical Analysis ◽

Contact Friction ◽

Curvature Effect ◽

Technical Problems ◽

Precise Calculation ◽

Gap Element ◽

Space Beam Element

The design and mechanical analysis of fracturing string was one of the key technical problems in fracturing operation. Considering contact friction and curvature effect, contact nonlinear problem of fracturing string was solved by space beam element and multidirectional contact gap element method. Contact state, contact reaction force and corresponding frictional resistance between the fracturing string and borehole or inside casing wall could be accurately described by gap element, which generated less simplification in the mechanical model and more precise calculation of force and deformation. The calculations of field examples has shown that while the distance is 10 m, 20 m or 30 m between two packers of fracturing string, maximum axial sliding displacement of the first packer is 0.19 mm and sliding displacement of the second packer is 11.17mm, 23.78mm , or 36.46 mm. The theory basis is provided for the decision of reasonable distance between two packers.

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Discussion on “A calibration methodology to obtain material parameters for the representation of fracture mechanics based on discrete element simulations”

Computers and Geotechnics ◽

10.1016/j.compgeo.2017.03.001 ◽

2017 ◽

Vol 86 ◽

pp. 246-248 ◽

Cited By ~ 2

Author(s):

M.D. Wei ◽

F. Dai ◽

N.W. Xu ◽

Y. Liu

Keyword(s):

Fracture Mechanics ◽

Discrete Element ◽

Material Parameters ◽

Discrete Element Simulations

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Discrete element simulations of gravitational volcanic deformation: 2. Mechanical analysis

Journal of Geophysical Research Atmospheres ◽

10.1029/2004jb003253 ◽

2005 ◽

Vol 110 (B5) ◽

Cited By ~ 13

Author(s):

Julia K. Morgan

Keyword(s):

Discrete Element ◽

Mechanical Analysis ◽

Discrete Element Simulations

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A calibration methodology to obtain material parameters for the representation of fracture mechanics based on discrete element simulations

Computers and Geotechnics ◽

10.1016/j.compgeo.2016.08.029 ◽

2017 ◽

Vol 81 ◽

pp. 274-283 ◽

Cited By ~ 14

Author(s):

S. Behraftar ◽

S.A. Galindo Torres ◽

A. Scheuermann ◽

D.J. Williams ◽

E.A.G. Marques ◽

...

Keyword(s):

Fracture Mechanics ◽

Discrete Element ◽

Material Parameters ◽

Discrete Element Simulations

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Fracture Mechanical Analysis of Thin-Walled Cylindrical Shells with Cracks

Metals ◽

10.3390/met11040592 ◽

2021 ◽

Vol 11 (4) ◽

pp. 592

Author(s):

Feng Yue ◽

Ziyan Wu

Keyword(s):

Fracture Mechanics ◽

Tensile Stress ◽

Failure Modes ◽

Cylindrical Shells ◽

Crack Tip ◽

Mechanical Analysis ◽

J Integral ◽

Thin Walled Structures ◽

Circumferential Tensile Stress ◽

Thin Walled

The fracture mechanical behaviour of thin-walled structures with cracks is highly significant for structural strength design, safety and reliability analysis, and defect evaluation. In this study, the effects of various factors on the fracture parameters, crack initiation angles and plastic zones of thin-walled cylindrical shells with cracks are investigated. First, based on the J-integral and displacement extrapolation methods, the stress intensity factors of thin-walled cylindrical shells with circumferential cracks and compound cracks are studied using linear elastic fracture mechanics, respectively. Second, based on the theory of maximum circumferential tensile stress of compound cracks, the number of singular elements at a crack tip is varied to determine the node of the element corresponding to the maximum circumferential tensile stress, and the initiation angle for a compound crack is predicted. Third, based on the J-integral theory, the size of the plastic zone and J-integral of a thin-walled cylindrical shell with a circumferential crack are analysed, using elastic-plastic fracture mechanics. The results show that the stress in front of a crack tip does not increase after reaching the yield strength and enters the stage of plastic development, and the predicted initiation angle of an oblique crack mainly depends on its original inclination angle. The conclusions have theoretical and engineering significance for the selection of the fracture criteria and determination of the failure modes of thin-walled structures with cracks.

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Assimilation of Dynamic Combined Finite Discrete Element Methods Using the Ensemble Kalman Filter

Applied Sciences ◽

10.3390/app11072898 ◽

2021 ◽

Vol 11 (7) ◽

pp. 2898

Author(s):

Humberto C. Godinez ◽

Esteban Rougier

Keyword(s):

Kalman Filter ◽

Ensemble Kalman Filter ◽

Failure Modes ◽

Split Hopkinson Pressure Bar ◽

Peak Stress ◽

Discrete Element ◽

Material Behavior ◽

Model Parameters ◽

Hopkinson Pressure Bar ◽

Parameter Values

Simulation of fracture initiation, propagation, and arrest is a problem of interest for many applications in the scientific community. There are a number of numerical methods used for this purpose, and among the most widely accepted is the combined finite-discrete element method (FDEM). To model fracture with FDEM, material behavior is described by specifying a combination of elastic properties, strengths (in the normal and tangential directions), and energy dissipated in failure modes I and II, which are modeled by incorporating a parameterized softening curve defining a post-peak stress-displacement relationship unique to each material. In this work, we implement a data assimilation method to estimate key model parameter values with the objective of improving the calibration processes for FDEM fracture simulations. Specifically, we implement the ensemble Kalman filter assimilation method to the Hybrid Optimization Software Suite (HOSS), a FDEM-based code which was developed for the simulation of fracture and fragmentation behavior. We present a set of assimilation experiments to match the numerical results obtained for a Split Hopkinson Pressure Bar (SHPB) model with experimental observations for granite. We achieved this by calibrating a subset of model parameters. The results show a steady convergence of the assimilated parameter values towards observed time/stress curves from the SHPB observations. In particular, both tensile and shear strengths seem to be converging faster than the other parameters considered.

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