A stabilized nodally integrated meshfree formulation for fully coupled hydro-mechanical analysis of fluid-saturated porous media

Numerical modeling of reservoirs with low permeability or under undrained conditions often suffers from spurious fluid pressure oscillations due to the improper construction of approximation spaces. To address this issue, a fully coupled, stabilized meshfree formulation is developed based on a fluid pressure projection method, in which an additional stabilization term is added to the variational equation to correct the deficiency of the equal-order u-p reproducing kernel approximation. The projection scheme is formulated under the framework of the stabilized conforming nodal integration which enables a significant enhancement of the computational efficiency and accuracy, and the spurious low-energy modes of nodal integration are also eliminated. The effectiveness of the proposed stabilized meshfree formulation is demonstrated by solving several benchmark problems.