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.

Three-dimensional face stability analysis of shallow tunnels using numerical limit analysis and material point method

2021 ◽  
Vol 112 ◽  
pp. 103904
Author(s):  
Fabricio Fernández ◽  
Jhonatan E.G. Rojas ◽  
Eurípedes A. Vargas ◽  
Raquel Q. Velloso ◽  
Daniel Dias
Keyword(s):  
Stability Analysis ◽  
Limit Analysis ◽  
Three Dimensional ◽  
Material Point Method ◽  
Material Point ◽  
Point Method ◽  
Face Stability ◽  
Shallow Tunnels ◽  
Dimensional Face

scholarly journals Dam Breach Simulation with the Material Point Method

Computation ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 8
Author(s):  
Chendi Cao ◽  
Mitchell Neilsen
Keyword(s):  
Material Point Method ◽  
Mixture Theory ◽  
Material Point ◽  
Point Method ◽  
Internal Erosion ◽  
Dam Breach ◽  
New Model ◽  
Hencky Strain ◽  
The Impact ◽  
Soil And Water

Dam embankment breaches caused by overtopping or internal erosion can impact both life and property downstream. It is important to accurately predict the amount of erosion, peak discharge, and the resulting downstream flow. This paper presents a new model based on the material point method to simulate soil and water interaction and predict failure rate parameters. The model assumes that the dam consists of a homogeneous embankment constructed with cohesive soil, and water inflow is defined by a hydrograph using other readily available reach routing software. The model uses continuum mixture theory to describe each phase where each species individually obeys the conservation of mass and momentum. A two-grid material point method is used to discretize the governing equations. The Drucker–Prager plastic flow model, combined with a Hencky strain-based hyperelasticity model, is used to compute soil stress. Water is modeled as a weakly compressible fluid. Analysis of the model demonstrates the efficacy of our approach for existing examples of overtopping dam breach, dam failures, and collisions. Simulation results from our model are compared with a physical-based breach model, WinDAM C. The new model can capture water and soil interaction at a finer granularity than WinDAM C. The new model gradually removes the granular material during the breach process. The impact of material properties on the dam breach process is also analyzed.

scholarly journals An explicit GPU-based material point method solver for elastoplastic problems (ep2-3De v1.0)

2021 ◽  
Vol 14 (12) ◽  
pp. 7749-7774
Author(s):  
Emmanuel Wyser ◽  
Yury Alkhimenkov ◽  
Michel Jaboyedoff ◽  
Yury Y. Podladchikov
Keyword(s):  
Graphics Processing Units ◽  
High Performance ◽  
Three Dimensional ◽  
Material Point Method ◽  
Failure Surface ◽  
Material Point ◽  
Numerical Results ◽  
Point Method ◽  
Background Mesh ◽  
Material Points

Abstract. We propose an explicit GPU-based solver within the material point method (MPM) framework using graphics processing units (GPUs) to resolve elastoplastic problems under two- and three-dimensional configurations (i.e. granular collapses and slumping mechanics). Modern GPU architectures, including Ampere, Turing and Volta, provide a computational framework that is well suited to the locality of the material point method in view of high-performance computing. For intense and non-local computational aspects (i.e. the back-and-forth mapping between the nodes of the background mesh and the material points), we use straightforward atomic operations (the scattering paradigm). We select the generalized interpolation material point method (GIMPM) to resolve the cell-crossing error, which typically arises in the original MPM, because of the C0 continuity of the linear basis function. We validate our GPU-based in-house solver by comparing numerical results for granular collapses with the available experimental data sets. Good agreement is found between the numerical results and experimental results for the free surface and failure surface. We further evaluate the performance of our GPU-based implementation for the three-dimensional elastoplastic slumping mechanics problem. We report (i) a maximum 200-fold performance gain between a CPU- and a single-GPU-based implementation, provided that (ii) the hardware limit (i.e. the peak memory bandwidth) of the device is reached. Furthermore, our multi-GPU implementation can resolve models with nearly a billion material points. We finally showcase an application to slumping mechanics and demonstrate the importance of a three-dimensional configuration coupled with heterogeneous properties to resolve complex material behaviour.

Modeling of the impact of rigid ellipsoidal blocks by means of an elastic-visco-plastic constitutive model 

2021 ◽  
Author(s):  
Giuseppe Dattola ◽  
Giovanni Battista Crosta ◽  
Claudio Giulio di Prisco
Keyword(s):  
Constitutive Model ◽  
Three Dimensional ◽  
Impact Angle ◽  
Material Point ◽  
Lumped Mass ◽  
Mountain Areas ◽  
Block Motion ◽  
The Impact ◽  
Constitutive Parameters

<p>Rockfall is one of the most common hazards in mountain areas causing severe damages to structures/infrastructures and, human lives. For this reason, numerous are the papers published in the last decades on this subject, both introducing reliable approaches to simulate the boulder trajectory and defining design methods for sheltering structures. As is well known, the most popular strategy to simulate the block trajectory and velocity is based on the lumped mass material point approach. This is capable of describing the block trajectory, before either its natural arrest or impact against an artificial/natural obstacle, by suitably considering its interaction with soil/rock materials, interaction always dynamic, very often highly dissipative and defined, according to its nature, as sliding, rolling or impact.</p><p>In this framework, this study focusses on impacts and, in particular, on the role of block geometry in affecting the block kinematic response. The problem is approached numerically; by modifying a previously conceived elastic-viscoplastic constitutive model, based on the macro-element concept. and capable of satisfactorily simulating impacts of spherical blocks.</p><p>The modified constitutive model relaxes the assumption of spherical block by assuming an ellipsoidal shape and by allowing for the boulder rotation. These two changes make the problem more complex but allow to model more realistically the impact. For the sake of simplicity, the results shown in this work consider the block motion to be planar, but the model already allows to include general three dimensional conditions.</p><p>In this work, the model is briefly outlined and the procedure for calibrating the model constitutive parameters described. Then, the results of an extensive parametric analysis, employing constitutive parameters calibrated on experimental data taken from the literature, are discussed. In particular, the role of (i) the inner block orientation, and (ii) the inner impact angle is considered in terms of both kinematic variables and restitution coefficients. Finally, interpolation functions to compute restitution coefficients, once both block shape and inner impact block orientation are known, are provided.</p>

Three-dimensional material point method modeling of runout behavior of the Hongshiyan landslide

2019 ◽  
Vol 56 (9) ◽  
pp. 1318-1337 ◽  
Author(s):  
Xiaorong Xu ◽  
Feng Jin ◽  
Qicheng Sun ◽  
Kenichi Soga ◽  
Gordon G.D. Zhou
Keyword(s):  
Progressive Failure ◽  
Three Dimensional ◽  
Material Point Method ◽  
Numerical Approach ◽  
Flow Speed ◽  
Material Point ◽  
Point Method ◽  
Field Scale ◽  
Rate Dependent ◽  
Depth Direction

This study presents a field-scale simulation of the Hongshiyan landslide in China. It uses an advanced numerical approach (material point method (MPM)) and a constitutive model (the Drucker–Prager model + μ(I) rheological relation) for the three-dimensional (3D) simulation. The performance of the developed MPM model is validated with laboratory-scale experimental data on granular collapse before being applied to field-scale analyses. ArcGIS data are used to create a 3D MPM model of the soil body with complicated geometry. Although the developed model can describe the multiple phases of granular flow, it focuses on the runout behavior of the landslide in this work. The landslide is assumed to have occurred suddenly due to an earthquake, and global sudden failure rather than progressive failure is modeled. The MPM simulation results match reasonably well with the measured post-earthquake topography (e.g., deposit height of about 120 m and stretch length of about 900 m in the river) and landslide duration of about 1 min. The velocity of the sliding mass increases rapidly during flow, especially in the first 20 s. The velocity profiles along the depth direction at different locations of the sliding body exhibit an exponential distribution similar to that of a Bagnold-type profile, indicating that the sliding body is fully mobilized. The rate-dependent dissipation parameter β used in the model significantly influences the runout behavior (e.g., flow speed, velocity distribution, and deposit shape).

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 An investigation of stress inaccuracies and proposed solution in the material point method

2019 ◽  
Vol 65 (2) ◽  
pp. 555-581 ◽  
Author(s):  
José Leόn González Acosta ◽  
Philip J. Vardon ◽  
Guido Remmerswaal ◽  
Michael A. Hicks
Keyword(s):  
Shape Function ◽  
Time Integration ◽  
Three Dimensional ◽  
Constitutive Models ◽  
Material Point Method ◽  
Material Point ◽  
Point Method ◽  
Implicit Time ◽  
Integration Scheme ◽  
Time Integration Scheme

AbstractStress inaccuracies (oscillations) are one of the main problems in the material point method (MPM), especially when advanced constitutive models are used. The origins of such oscillations are a combination of poor force and stiffness integration, stress recovery inaccuracies, and cell crossing problems. These are caused mainly by the use of shape function gradients and the use of material points for integration in MPM. The most common techniques developed to reduce stress oscillations consider adapting the shape function gradients so that they are continuous at the nodes. These techniques improve MPM, but problems remain, particularly in two and three dimensional cases. In this paper, the stress inaccuracies are investigated in detail, with particular reference to an implicit time integration scheme. Three modifications to MPM are implemented, and together these are able to remove almost all of the observed oscillations.

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.

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