scholarly journals Symplectic Time Integration Methods for the Material Point Method

2021 ◽  
Author(s):  
M. Berzins
Keyword(s):  
Time Integration ◽  
Material Point Method ◽  
Material Point ◽  
Point Method ◽  
Integration Methods ◽  
Time Integration Methods

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.

Axisymmetric Generalized Interpolation Material Point Method for Fully Coupled Thermomechanical Evaluation of Transient Responses

2019 ◽  
Vol 17 (04) ◽  
pp. 1950003
Author(s):  
Jun Tao ◽  
Yonggang Zheng ◽  
Hongwu Zhang ◽  
Zhen Chen
Keyword(s):  
Time Integration ◽  
Three Dimensional ◽  
Material Point Method ◽  
Coupled System ◽  
Thermomechanical Analysis ◽  
Solution Procedure ◽  
Material Point ◽  
Point Method ◽  
Transient Responses ◽  
Fully Coupled

In this paper, an axisymmetric generalized interpolation material point method for fully coupled thermomechanical analysis (AxiCTGIMP) is developed for evaluating the transient responses, where both the thermoelastic and thermoplastic effects are taken into account. The generalized interpolation material point method (GIMP) discretization in space for the coupled governing equations is described in detail. A staggered solution scheme is designed to split the coupled system into the parts related to the temperature and displacement fields, respectively, which are then solved individually with explicit time integration. The AxiCTGIMP is then verified and validated with two benchmark examples: the thick-walled cylinder and the Taylor-bar impact test. The simulation results show good agreements with available analytical solutions, experimental data and other numerical results. In addition, the results indicate that the proposed solution procedure is more accurate than the original MPM while it is much more efficient than the fully three-dimensional simulation for the axisymmetric thermomechanical problems.

scholarly journals A Hybrid Material Point Method for Frictional Contact with Diverse Materials

2019 ◽  
Vol 2 (2) ◽  
pp. 1-24 ◽  
Author(s):  
Xuchen Han ◽  
Theodore F. Gast ◽  
Qi Guo ◽  
Stephanie Wang ◽  
Chenfanfu Jiang ◽  
...  
Keyword(s):  
Hybrid Material ◽  
Frictional Contact ◽  
Material Point Method ◽  
Material Point ◽  
Point Method

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.

Sign in / Sign up

Export Citation Format

Share Document