Meshfree method for 2-D forward modeling of gravity anomaly

Meshfree method as a kind of new numerical method has the advantages of high precision, high order function structure and convenient loading of physical properties, is widely applied in the field of computational mechanics. The meshfree method including PIM, RPIM and EFGM was used in the two-dimensional forward calculation of gravity anomaly field. Firstly, from the 2-D variational problem of gravity anomaly, the corresponding meshfree discrete system matrix expression was deduced by combining Galerkin method and Gauss integral formula. Then suggested values of the shape parameters of RPIM-MQ, RPIM-exp and EFGM-exp were obtained by numerical experiments, the calculation results of different meshfree methods under optimal shape parameters were compared and analyzed. The conclusions are verified as follow:Meshfree method is suitable for 2-D forward modeling of gravity anomaly with big variation of the distribution of medium physical properties, the optimal interval of exponential function shape parameter α_c is in range of 1.5 to 1.7, the proposed value of β is 0.6 and the proposed interval of q in MQ function is in range of-4.1 to 1.9, EFGM has higher computational accuracy than PIM and RPIM.