scholarly journals Impact Fracture and Fragmentation of Glass via the 3D Combined Finite-Discrete Element Method

2021 ◽  
Vol 11 (6) ◽  
pp. 2484
Author(s):  
Zhou Lei ◽  
Esteban Rougier ◽  
Earl E. Knight ◽  
Mengyan Zang ◽  
Antonio Munjiza
Keyword(s):  
Discrete Element Method ◽  
Automobile Industry ◽  
Glass Plate ◽  
Discrete Element ◽  
Impact Fracture ◽  
Constitutive Relationship ◽  
Laminated Glass ◽  
Fracture Patterns ◽  
Fracture Processes ◽  
Element Method

A driving technical concern for the automobile industry is their assurance that developed windshield products meet Federal safety standards. Besides conducting innumerable glass breakage experiments, product developers also have the option of utilizing numerical approaches that can provide further insight into glass impact breakage, fracture, and fragmentation. The combined finite-discrete element method (FDEM) is one such tool and was used in this study to investigate 3D impact glass fracture processes. To enable this analysis, a generalized traction-separation model, which defines the constitutive relationship between the traction and separation in FDEM cohesive zone models, was introduced. The mechanical responses of a laminated glass and a glass plate under impact were then analyzed. For laminated glass, an impact fracture process was investigated and results were compared against corresponding experiments. Correspondingly, two glass plate impact fracture patterns, i.e., concentric fractures and radial fractures, were simulated. The results show that for both cases, FDEM simulated fracture processes and fracture patterns are in good agreement with the experimental observations. The work demonstrates that FDEM is an effective tool for modeling of fracture and fragmentation in glass.

Structural Optimization of Laminated Glass Plate Using Discrete Element Method

2015 ◽  
Vol 1088 ◽  
pp. 716-720 ◽  
Author(s):  
Shinobu Sakai ◽  
Kensuke Maenaka ◽  
Koetsu Yamazaki
Keyword(s):  
Tensile Strength ◽  
Discrete Element Method ◽  
Adhesive Strength ◽  
Fracture Behavior ◽  
Glass Plate ◽  
Discrete Element ◽  
Impact Fracture ◽  
Laminated Glass ◽  
Impact Fracture Behavior ◽  
The Impact

Laminated glass is widely used to enhance structural functions. The impact fracture behavior of laminated glass is more complicated than that of single glass, because of the combined influences of the large deformation and delamination strengths. In this study, the impact fracture behavior of a laminated glass plate intended for the outside surface of a modern building has been studied by numerical simulations and experiments. This fracture simulation was calculated using a Discrete Element Method (DEM) based on non-continuum mechanics. The laminated glass structures have been optimized for attaining maximum durability against impact fracture based on the response surface method. In the optimum problem, the tensile strength of the interlayer and the adhesive strength between two pieces of glass and the interlayer are taken as the design variables. From the results of the optimization, it has been observed that the laminated glass difficult to break in the case that the tensile strength was high and that the adhesive strength was a little light. The penetration performance of an optimized laminated glass plate was noticeably better in comparison with a commercial laminated glass plate.

scholarly journals A discrete element method model of corn stalk and its mechanical characteristic parameters

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 9337-9350
Author(s):  
Tao Zhang ◽  
Manquan Zhao ◽  
Fei Liu ◽  
Haiqing Tian ◽  
Tuya Wulan ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Discrete Element Method ◽  
Compression Fracture ◽  
Discrete Element ◽  
Optimal Combination ◽  
Impact Fracture ◽  
Corn Stalk ◽  
Corn Straw ◽  
Bending Fracture ◽  
Element Method

In a simulation model of the process of corn straw crushing, its physical parameters and the model itself influence the accuracy of the numerical calculations of the discrete element method. This study attempts to improve the simulation accuracy of the crushing process and to find the optimal combination of parameters. Based on the Hertz-Mindlin with Bonding contact model, multiple particle replacement and bonding programs written using Visual Studio were imported through the application programming interface (API) of a discrete element method (DEM) model to establish three particle-bonding materials for a numerical simulation of the crushing process. Using results of mechanical corn stalk tests, DEM simulations of impact fracture, compression fracture, and bending fracture were conducted to determine the optimal combination of parameters. The resultant DEM-parameter combination led to simulation errors of 3.83%, 5.95%, and 7.86% in numerical simulations of impact fracture, bending fracture, and compression fracture of corn stalks, respectively. The performance of the corn stalk DEM using the proposed optimal parameter combination was validated using a 9RS-60 corn stalk crusher, revealing that the numerical simulation error was 8.77%. This study can improve the accuracy of the discrete element method in the simulation of the corn straw breaking process.

Influence of mesh orientation in discrete element method simulations of fracture processes

2018 ◽  
Vol 53 (6) ◽  
pp. 400-407 ◽  
Author(s):  
Gabriel Birck ◽  
Ignacio Iturrioz ◽  
Jorge D Riera ◽  
Letícia FF Miguel
Keyword(s):  
Discrete Element Method ◽  
Failure Modes ◽  
Discrete Element ◽  
Tensile Fracture ◽  
Unconfined Compression ◽  
Numerical Predictions ◽  
Homogeneous Stress ◽  
Cylindrical Samples ◽  
Fracture Processes ◽  
Element Method

The lattice discrete element method was employed by the authors in numerical determinations of the pre and post peak-failure response of quasi-brittle systems in which tensile fracture typically controls the dominant failure modes. In previous publications, the approach has also been applied to structures that fail by shear or unconfined compression. It was also verified that discrete element method models predict the strength of cubic and cylindrical samples subjected to confining lateral pressures up to about 20% of the vertical stress, although overestimating the effect of confinement. One of the factors responsible for this overestimation may be associated to the restraints on the fracture paths introduced by numerical methods such as discrete element method or finite element method . In order to determine a bound on model error in discrete element method numerical predictions, in this article, the influence of the mesh orientation on simulations of fracture propagation in quasi-brittle materials is examined in case of a plate subjected to a nominally homogeneous stress state.

Discrete element method to model cracking for two layer systems

TAPPI Journal ◽  
2019 ◽  
Vol 18 (2) ◽  
pp. 101-108
Author(s):  
Daniel Varney ◽  
Douglas Bousfield
Keyword(s):  
Discrete Element Method ◽  
Flexural Modulus ◽  
Single Layer ◽  
Discrete Element ◽  
Flexural Stress ◽  
Layer System ◽  
Three Point Bending ◽  
Moving Force ◽  
Coating Layers ◽  
Element Method

Cracking at the fold is a serious issue for many grades of coated paper and coated board. Some recent work has suggested methods to minimize this problem by using two or more coating layers of different properties. A discrete element method (DEM) has been used to model deformation events for single layer coating systems such as in-plain and out-of-plain tension, three-point bending, and a novel moving force picking simulation, but nothing has been reported related to multiple coating layers. In this paper, a DEM model has been expanded to predict the three-point bending response of a two-layer system. The main factors evaluated include the use of different binder systems in each layer and the ratio of the bottom and top layer weights. As in the past, the properties of the binder and the binder concentration are input parameters. The model can predict crack formation that is a function of these two sets of factors. In addition, the model can predict the flexural modulus, the maximum flexural stress, and the strain-at-failure. The predictions are qualitatively compared with experimental results reported in the literature.

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