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Meshfree and particle methods and their applications - TAM ...

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18 Li <strong>and</strong> Liu: <strong>Meshfree</strong> <strong>and</strong> <strong>particle</strong> <strong>methods</strong> <strong>and</strong> <strong>applications</strong> Appl Mech Rev vol 55, no 1, January 2002<br />

It is worth mentioning that Hao et al 280 used RKPM<br />

combined with finite element method in a micro-mechanics<br />

damage simulation. In that study, a multiple scale RKPM is<br />

used to simulate a ductile fracture process involving damage<br />

evolution, <strong>and</strong> multiresolution analysis has also been performed<br />

on shear b<strong>and</strong>s formation. The numerical results<br />

show that the multiple scale RKPM possesses a strong ability<br />

to capture physical phenomena such as shear b<strong>and</strong>, large<br />

deformation, <strong>and</strong> the material instability during damage evolution.<br />

Zhang et al 283 used EFG to model the jointed rock<br />

structures; Aluru 96 used RKPM to analyze microelectromechanical<br />

system. Danielson et al 284,285 has been developing<br />

a new communication scheme for parallel implementation<br />

of RKPM formulation. They have tested a quarter<br />

million <strong>particle</strong> computations in Cray T3E supercomputer in<br />

simulations of shear b<strong>and</strong> <strong>and</strong> fracture. Recently, Zhang et al<br />

286 have developed a parallel version of 3D RKPM code<br />

in implicit CFD calculation, which has the capacity to deal<br />

with more than one million <strong>particle</strong>s. A novel procedure of<br />

implementing the essential boundary condition by using the<br />

bridging scale hierarchical enrichment, <strong>and</strong> the associated<br />

parallel communication with different processors is presented<br />

in that paper.<br />

A simple illustration of the multiresolution meshfree<br />

method is given in Figs. 12 <strong>and</strong> 13. Figure 12 depicts the<br />

analysis of large deformation solids <strong>and</strong> the plastic deformation<br />

of a notched bar. The high scale solution Fig. 12c is an<br />

extraction from the total solution Fig. 12b. It shows the<br />

crack tip field <strong>and</strong> the localized shear b<strong>and</strong>s. The quantitative<br />

experimental result is given in Fig. 12a. Similarly, Fig. 13a<br />

depicts the high scale solution obtained by wavelets decomposition<br />

of the total scale solution for the pressure from the<br />

analysis of the compressible flow-structure interaction. This<br />

figure, labeled High scale clearly indicates the shock location<br />

<strong>and</strong> this solution can be used as an error indicator to guide<br />

the adaptivity which is simply implemented by addition of<br />

appropriately placed <strong>particle</strong>s in the meshfree method. The<br />

total solution is given in Fig. 13b.<br />

Due to the difficulties in imposing essential boundary<br />

conditions, a special meshfree contact algorithm is needed<br />

Fig. 11<br />

<strong>Meshfree</strong> simulation of curved dynamic shear b<strong>and</strong>: a experimental observation; b meshfree calculation 248<br />

Fig. 12<br />

Multi-scale <strong>Meshfree</strong> Simulation of strain localization of three point bending test

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