Material Point Method Modelling of Granular Flow in Inclined Channels

2014 ◽  
Vol 553 ◽  
pp. 501-506 ◽  
Author(s):  
Wojciech Tomasz Sołowski ◽  
Scott William Sloan
Keyword(s):  
Constitutive Model ◽  
Granular Material ◽  
Granular Flow ◽  
Numerical Technique ◽  
Material Point Method ◽  
Material Point ◽  
Point Method ◽  
Experimental Results ◽  
Inclined Channels

The material point method is a novel numerical technique which is especially well-suited to solving problems involving large or extreme deformations. This paper shows the results of the modelling of flow of granular material in inclined channels. During the calculations the granular material is approximated by a Mohr-Coulomb constitutive model. The computed flow is subsequently compared to experimental results published in the literature.

scholarly journals Simulation of size segregation in granular flow with material point method

2017 ◽  
Vol 140 ◽  
pp. 11010
Author(s):  
Minglong Fei ◽  
Qicheng Sun ◽  
Kimberly Hill ◽  
Gordon G. D. Zhou
Keyword(s):  
Granular Flow ◽  
Material Point Method ◽  
Material Point ◽  
Point Method ◽  
Size Segregation

scholarly journals Analysis of the Slope Response to an Increase in Pore Water Pressure Using the Material Point Method

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1446 ◽  
Author(s):  
Troncone ◽  
Conte ◽  
Pugliese
Keyword(s):  
Pore Water ◽  
Slip Surface ◽  
Pore Water Pressure ◽  
Numerical Technique ◽  
Water Pressure ◽  
Material Point Method ◽  
Material Point ◽  
Point Method ◽  
Major Influence ◽  
Preliminary Evaluation

Traditional numerical methods, such as the finite element method or the finite difference method, are generally used to analyze the slope response in the pre-failure and failure stages. The post-failure phase is often ignored due to the unsuitability of these methods for dealing with problems involving large deformations. However, an adequate analysis of this latter stage and a reliable prediction of the landslide kinematics after failure are very useful for minimizing the risk of catastrophic damage. This is generally the case of the landslides triggered by an excess in pore water pressure, which are often characterized by high velocity and long run-out distance. In the present paper, the deformation processes occurring in an ideal slope owing to an increase in pore water pressure are analyzed using the material point method (MPM) that is a numerical technique capable of overcoming the limitations of the above-mentioned traditional methods. In particular, this study is aimed to investigate the influence of the main involved parameters on the development of a slip surface within the slope, and on the kinematics of the consequent landslide. The obtained results show that, among these parameters, the excess water pressure exerts the major influence on the slope response. A simple equation is also proposed for a preliminary evaluation of the run-out distance of the displaced soil mass.

Hierarchical multiscale simulations of crystalline β-octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (β-HMX): Generalized interpolation material point method simulations of brittle fracture using an elastodamage model derived from molecular dynamics

2017 ◽  
Vol 26 (2) ◽  
pp. 293-313 ◽  
Author(s):  
Shan Jiang ◽  
Jun Tao ◽  
Thomas D Sewell ◽  
Zhen Chen
Keyword(s):  
Molecular Dynamics ◽  
Constitutive Model ◽  
Material Point Method ◽  
Material Point ◽  
Point Method ◽  
External Loading ◽  
Multiscale Approach ◽  
Loading Conditions ◽  
Strain Relationship ◽  
Hierarchical Multiscale

A predictive constitutive model for single-crystal β-octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (β-HMX) under simple loading conditions was developed using a hierarchical multiscale approach based on molecular dynamics and the generalized interpolation material point method. Basic mechanical behaviors, such as elastic and damage responses to external loading conditions, were predicted at the molecular level using molecular dynamics. The molecular dynamics results were used to construct a preliminary elastodamage model for the generalized interpolation material point (GIMP) simulations. Anisotropy of the β-HMX crystal, which affects the secant elastodamage stiffness tensor in the constitutive model, was taken into account. The GIMP method was used to deal with large deformation and fracture. GIMP results predicted using the hierarchically obtained elastodamage model are shown to be in close agreement with the molecular dynamics predictions. Although the evolution of local damage surfaces from GIMP is not as detailed as that from molecular dynamics, the main features of nonlinear elastodamage in the stress–strain relationship are captured by GIMP at reduced computational expense. Thus, this preliminary hierarchical multiscale procedure can be considered as useful for simulations of elastodamage behaviors in brittle materials for engineering purposes.

scholarly journals Numerical Simulation of Mesodamage Behavior of Concrete Based on Material Point Method

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Aihua Liu ◽  
Jiaqiang Zou ◽  
Wei Hu ◽  
Ming Liu ◽  
Peitong Cong ◽  
...  
Keyword(s):  
Numerical Model ◽  
Constitutive Model ◽  
Mechanical Behavior ◽  
Uniaxial Tension ◽  
Material Point Method ◽  
Material Point ◽  
Point Method ◽  
Damage Initiation ◽  
Numerical Tests ◽  
Random Aggregate

Concrete consists of coarse aggregates, mortar matrix, and interfacial transition zone (ITZ) between them at the mesoscale. Considering these three phases, many numerical tests have been conducted to study the mesodamage behavior of concrete, in which a variety of numerical methods have also been adopted. These methods are mainly based on the finite element method (FEM); however, some other methods have been proven to be helpful as well. For example, the material point method (MPM) has the advantage of building a numerical model based on pixel or voxel of the image and is capable of solving large deformation problems. In view of this, MPM is introduced in this paper. Firstly, a method for establishing the numerical specimen is put forward, considering the original sample of its mesoscopic geometric character. Then, a stochastic damage constitutive model considering the heterogeneity of the concrete is proposed. Next, the numerical model and the constitutive model are incorporated into an MPM code to conduct numerical tests. The uniaxial tension and compression tests of a random-aggregate model and a double-aggregate specimen under uniaxial tension are then simulated numerically to validate the proposed method. Results show that the proposed method can well capture the main macroscopic mechanical behavior of concrete and the mesoscopic damage initiation and propagation. It is also found that MPM can save the time of model establishing and improve calculation efficiency. The influences of different parameters of the proposed constitutive model are also clarified through a parametric study. The proposed method can provide a useful tool for concrete numerical testing and for studying the mechanical behavior of concrete at mesoscale.

scholarly journals Modeling of the Split-Hopkinson-Pressure-Bar experiment with the explicit material point method

2021 ◽  
Author(s):  
S. F. Maassen ◽  
R. Niekamp ◽  
J. A. Bergmann ◽  
F. Pöhl ◽  
J. Schröder ◽  
...  
Keyword(s):  
Split Hopkinson Pressure Bar ◽  
Material Point Method ◽  
Material Point ◽  
Point Method ◽  
Experimental Results ◽  
Hopkinson Pressure Bar ◽  
Solution Approach ◽  
High Deformation ◽  
Split Hopkinson ◽  
Pressure Bar

AbstractThe material point method (MPM) represents an alternative discretization method for numerical simulations. It aims to combine the benefits of a Lagrangian representation of bodies and an Eulerian numerical solution approach. Therefore, especially at high material deformations the method is not prone to mesh distortions such as the finite element method (FEM). For this reason, the MPM is used to a great extent for modeling granular materials as in geo-mechanics. However, high deformations occur in many industrial processes on metallic materials. The Split-Hopkinson-Pressure-Bar (SHPB) experiment is used to characterize material properties at high deformation rates. Although widely used, this experiment is not yet standardized and shows a variety of sensitivities, e.g. to friction. Inter alia for this reason, simulations are conducted with the experiment to allow for a better evaluation of the measured data. The purpose of this work from an engineering point of view is to analyze the performance of the MPM on an SHPB experiment. In order to validate the experimental results for the material characterization under dynamic loading conditions we introduce frictional contact. We use arbitrary tri-linear brick domains in a 3D CPDI1 scheme, instead of originally used parallelepipeds. This allows for a more flexible geometry approximation using standard meshes. The results of the method are analyzed with respect to discretization sensitivity and discussed in the context of the experimental results for a 42CrMo4 steel. We were able to show that the method is capable to reproduce the SHPB experiment. Additionally the method shows convergency in the results with finer discretizations. Thus, the MPM has underlined its importance as an alternative simulation technique for problems with high deformation.

NUMERICAL SIMULATION OF HUMAN HEAD IMPACT USING THE MATERIAL POINT METHOD

2013 ◽  
Vol 10 (04) ◽  
pp. 1350014 ◽  
Author(s):  
SHUANGZHEN ZHOU ◽  
XIONG ZHANG ◽  
HONGLEI MA
Keyword(s):  
Constitutive Model ◽  
Brain Tissue ◽  
Three Dimensional ◽  
Material Point Method ◽  
Human Head ◽  
Material Point ◽  
Point Method ◽  
Skull Bone ◽  
Ball Impact ◽  
The Impact

In this paper, a three-dimensional material point human head model is constructed from the computed tomography (CT) scanned images of an adult male volunteer, and used to study the dynamic response of human head under the impact of a three-dimensional cylindrical lead projectile with a speed of 6.4 m/s. The model consists of skull bone, brain tissue and membrane of human head, which is close to the real one. The skull and membrane are modeled by an elastic constitutive model, and the brain tissue is modeled by an anisotropic viscoelastic constitutive model. These constitutive models have been implemented in our three-dimensional explicit material point method code, MPM3D, and is verified by comparing its numerical results for a ball impact problem with those obtained by LS-DYNA. The simulation results help illustrate the response of skull bone, membrane and brain tissues subjected to impact, which contributes to the understanding of the biomechanics and mechanisms of head injury.

Simulation of Soft Tissue Failure Using the Material Point Method

2006 ◽  
Vol 128 (6) ◽  
pp. 917-924 ◽  
Author(s):  
Irina Ionescu ◽  
James E. Guilkey ◽  
Martin Berzins ◽  
Robert M. Kirby ◽  
Jeffrey A. Weiss
Keyword(s):  
Soft Tissue ◽  
Constitutive Model ◽  
Simple Shear ◽  
Solid Mechanics ◽  
Soft Tissues ◽  
Material Point Method ◽  
Material Point ◽  
Point Method ◽  
Time Step ◽  
Soft Tissue Failure

Understanding the factors that control the extent of tissue damage as a result of material failure in soft tissues may provide means to improve diagnosis and treatment of soft tissue injuries. The objective of this research was to develop and test a computational framework for the study of the failure of anisotropic soft tissues subjected to finite deformation. An anisotropic constitutive model incorporating strain-based failure criteria was implemented in an existing computational solid mechanics software based on the material point method (MPM), a quasi-meshless particle method for simulations in computational mechanics. The constitutive model and the strain-based failure formulations were tested using simulations of simple shear and tensile mechanical tests. The model was then applied to investigate a scenario of a penetrating injury: a low-speed projectile was released through a myocardial material slab. Sensitivity studies were performed to establish the necessary grid resolution and time-step size. Results of the simple shear and tensile test simulations demonstrated the correct implementation of the constitutive model and the influence of both fiber family and matrix failure on predictions of overall tissue failure. The slab penetration simulations produced physically realistic wound tracts, exhibiting diameter increase from entrance to exit. Simulations examining the effect of bullet initial velocity showed that the anisotropy influenced the shape and size of the exit wound more at lower velocities. Furthermore, the size and taper of the wound cavity was smaller for the higher bullet velocity. It was concluded that these effects were due to the amount of momentum transfer. The results demonstrate the feasibility of using MPM and the associated failure model for large-scale numerical simulations of soft tissue failure.

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