In the present paper, forming of clamped triangular plates by means of water has been investigated. The plates were made of st-12 and had the thicknesses of 1 and 2 millimeters. The experimental tests were performed at the impact laboratory of Guilan University using drop hammer system. Various aspects of numerical investigation were simulated by Abaqus software. As mentioned above, using drop hammer system as a hydrodynamic loading tool and carrying out different empirical tests in this study, the effect of factors such as thickness, standoff distance of hammer and its weight, i.e. the applied momentum to the system have been studied. In the numerical simulations, the deformations of triangular plates were simulated by smoothed-particle hydrodynamics method. Also, the Fluid-Structure Interaction was considered for simulating the fluid phase and the plate deformation was modeled using finite element method in the form of coupled SPH/FEM. Furthermore, the ultimate deformation, stress distribution, stress concentration of plates and position of maximum deformation on triangular plate have been investigated. Agreement between the obtained data from numerical simulations and experiments guarantied the accuracy of simulations.