An Improved Contact Algorithm for the Material Point Method and Application to Stress Propagation in Granular Material

摘要: Contact between deformable bodies is a dif- cult problem in the analysis of engineering systems. A new approach to contact has been implemented us- ing Material Point Method for solid mechanics, Bar- denhagen, Brackbill, and Sulsky (2000a). Here two im- provements algorithm are described. The rst include normal traction logic more appropriately determine free separation crite- rion. second provide numerical stability by scaling impulse when computational grid in- formation suspect, condition which can be expected occur occasionally as material move through grid. modications described preserve important properties original algorithm, namely conservation momentum, use global quantities obviate need neighbor searches result cost linearly with number contacting bodies. demonstrated on several examples. Deformable body so- lutions compare favorably problems which, rigid bodies, have analytical solutions. much demanding simulation stress propagation ide- alized granular material, high delity data obtained, examined detail. Excellent quali- tative agreement found variety con- ditions. Important parameters needed quantitative comparisons identied.