基于增广拉格朗日乘子法的物质点接触算法

Material point method (MPM) is one kind of meshfree methods and has been attracting much attention in recent years.MPM shows advantages over traditional methods in problems of intensive impact loading, large deformation of rock and soil material and fluid-structure interaction.When MPM is applied in medium-velocity or low-velocity impact problems and fluid-structure interaction problems,special algorithms for contacts between different objects are usually required to ensure good accuracy.A new contact algorithm for MPM is proposed based on the augmented Lagrangian multiplier method.The new method is validated by examples of bar impact and fluid-structure interaction.Results show that interface penetration existing in original contact algorithms can be effectively solved by the new algorithm.Result oscillation aroused by the original contact algorithm can also be suppressed.