Shiwei Zhao^1,*, Hao Chen², Jidong Zhao¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.25, No.2, pp. 1-1, 2023, DOI:10.32604/icces.2023.09965

Abstract With global warming, thaw-induced landslides occur more frequently in permafrost, which not only threaten the safety of infrastructures as general geohazards but also worsen global warming due to carbon release. This work presents a novel computational framework to model thaw-induced landslides from a multiscale perspective. The proposed approach can capture the thermal-mechanical (TM) response of frozen soils at the particulate scale by using discrete element method (DEM). The micromechanics-based TM model is superior to capturing the sudden crash of soil skeletons caused by thaw-induced cementation loss between soil grains. The DEM-simulated TM response is then homogenized and directly fed into… More >

S. G. Bardenhagen^1,2, E. M. Kober³

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.6, pp. 477-496, 2004, DOI:10.3970/cmes.2004.005.477

Abstract The Material Point Method (MPM) discrete solution procedure for computational solid mechanics is generalized using a variational form and a Petrov–Galerkin discretization scheme, resulting in a family of methods named the Generalized Interpolation Material Point(GIMP) methods. The generalizationpermits identification with aspects of other point or node based discrete solution techniques which do not use a body–fixed grid, i.e. the “meshless methods”. Similarities are noted and some practical advantages relative to some of these methods are identified. Examples are used to demonstrate and explain numerical artifact noise which can be expected inMPM calculations. Thisnoiseresultsin non-physical local variations at the material points,… More >

Zhen Chen^1,2

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.3, pp. 48-48, 2019, DOI:10.32604/icces.2019.06164

Abstract Multi-phase transient interactions play an important role in modern engineering applications such as additive manufacturing, drilling, hydrofracturing, impact and penetration. It has been shown that the evolution of interfacial failure between different material phases has the nonlocal feature [1], namely, the stress state at a material point depends on the strain distribution around that point in a representative volume of certain size. Hence, local constitutive models cannot predict the real physics associated with interfacial failure evolution. On the other hand, the mesh-based methods cannot describe the real physics involved in the interfacial problems, due to the use of master/slave nodes… More >

Luming Shen¹, Zhen Chen²

CMES-Computer Modeling in Engineering & Sciences, Vol.7, No.3, pp. 305-320, 2005, DOI:10.3970/cmes.2005.007.305

Abstract To simulate the dynamic responses involving different material phases in a finite computational domain without discretizing the whole problem domain, a silent boundary scheme is proposed within the framework of the material point method (MPM) that is an extension from Computational Fluid Dynamics to Computational Solid Dynamics. Because the MPM does not employ fixed mesh connectivity, a robust spatial discretization procedure in the moving domain of influence could be designed by applying viscous damping forces along the computational boundary. To establish a simple interface between the discretization procedures with and without fixed mesh connectivity, a boundary layer is introduced to… More >

Y.J. Guo¹, J.A. Nairn²

CMES-Computer Modeling in Engineering & Sciences, Vol.113, No.4, pp. 389-410, 2017, DOI:10.3970/cmes.2017.113.389

Abstract This paper presents the principles and algorithms for simulation of dynamic crack propagation in elastic bodies by the material point method (MPM), from relatively simple two-dimensional cases to full three-dimensional, mixed-mode crack propagation. The paper is intended to give a summary of the latest achievements on simulation of three-dimensional dynamic crack propagation, which is essentially an unexplored area. Application of the methodology presented in this paper to several dynamic crack propagation problems has shown that the MPM is a reliable and powerful approach for simulating three-dimensional, mixed-mode crack propagation. More >

J. A. Nairn¹

CMES-Computer Modeling in Engineering & Sciences, Vol.92, No.3, pp. 271-299, 2013, DOI:10.32604/cmes.2013.092.271

Abstract The “multimaterial” version of the material point method (MPM) extrapolates each material to its own velocity field on a background grid. By reconciling momenta on nodes interacting with two or more materials, MPM is able to automatically handle contact without any need for special contact elements. This paper extends multimaterial MPM to automatically handle imperfect interfaces between materials as well. The approach is to evaluate displacement discontinuity on multimaterial nodes and then add internal forces and interfacial energy determined by an imperfect interface traction law. The concept is simple, but implementation required numerous corrections to make the analysis mesh independent,… More >

Y. J. Guo¹, J. A. Nairn²

CMES-Computer Modeling in Engineering & Sciences, Vol.16, No.3, pp. 141-156, 2006, DOI:10.3970/cmes.2006.016.141

Abstract This paper describes algorithms for three-dimensional dynamic stress and fracture analysis using the material point method (MPM). By allowing dual velocity fields at background grid nodes, the method provides exact numerical implementation of explicit cracks in a predominantly meshless method. Crack contact schemes were included for automatically preventing crack surfaces from interpenetration. Crack-tip parameters, dynamic$J$-integral vector and mode I, II, and III stress intensity factors, were calculated from the dynamic stress solution. Comparisons to finite difference method (FDM), finite element method (FEM), and boundary element method (BEM), as well as to static theories showed that MPM can efficiently and accurately… More >

Jin Ma, Hongbing Lu, Ranga Komanduri¹

CMES-Computer Modeling in Engineering & Sciences, Vol.12, No.3, pp. 213-228, 2006, DOI:10.3970/cmes.2006.012.213

Abstract The generalized interpolation material point (GIMP) method, recently developed using a C¹ continuous weighting function, has solved the numerical noise problem associated with material points just crossing the cell borders, so that it is suitable for simulation of relatively large deformation problems. However, this method typically uses a uniform mesh in computation when one level of material points is used, thus limiting its effectiveness in dealing with structures involving areas of high stress gradients. In this paper, a spatial refinement scheme of the structured grid for GIMP is presented for simulations with highly localized stress gradients. A uniform structured background… More >

Jin Ma¹, Jay C. Hanan¹, Ranga Komanduri¹, Hongbing Lu²

CMES-Computer Modeling in Engineering & Sciences, Vol.86, No.4, pp. 349-384, 2012, DOI:10.3970/cmes.2012.086.349

Abstract Amorphous metallic foams are an exciting class of materials for an array of high impact absorption applications, the mechanical behavior of which is only beginning to be characterized. To determine mechanical properties, guide processing, and engineer the microstructure for impact absorption, simulation of the mechanical properties is necessary as experimental determination alone can be expensive and time consuming. In this investigation, the material point method (MPM) with C1 continuous shape function is used to simulate the response of a bulk metallic glass (BMG) closed-cell foam (Pd42.5Cu30Ni7.5P20) under compression. The BMG foam was also tested experimentally under compression for validation of… More >

L. Chen¹ J. H. Lee¹, C.-f. Chen¹

CMES-Computer Modeling in Engineering & Sciences, Vol.86, No.3, pp. 199-224, 2012, DOI:10.3970/cmes.2012.086.199

Abstract This paper presents a numerical procedure to model surface tension using the Generalized Interpolation Material Point (GIMP) method which employs a background mesh in solving the equations of motion. The force due to surface tension is formulated at the mesh grid points by using the continuum surface force (CSF) model and then added to the equations of motion at each grid point. In GIMP, we use the grid mass as the color function in CSF and apply a moving average smoothing scheme to the grid mass to improve the accuracy in calculating the surface interface. The algorithm, named as GIMP-CSF,… More >