Drop weight impact test and numerical simulation of high-strength steel hull grillage

  Objectives   The numerical simulation analysis accuracy of hull structure under impact test, based on nonlinear finite element method(FEM), is affected by a series of simulation control parameters such as material constitution and failure definition, contact definition, element mesh size, etc., and the definitions of the aforementioned parameters require to be calibrated through model tests. In order to fully simulate the response characteristics of main energy-absorbing members on the side grillage structure of the real ship during the impact test, and make the calibration of the numerical simulation model test effective,

  Methods   a model structure with structural member dimensions close to the real ship and made of high-strength low alloy steel material is used, and a drop weight impact test of side grillage structure is carried out here. Then according to the resulting test records, we analyze the mechanism and mode of damage and deformation of the grillage under impact load, then accordingly conduct the numerical simulation analysis, and compare the finite element simulation results with the model test results.

  Results  The results show that the damage and deformation mode obtained from the numerical simulation is consistent with the model test result, and tearing failure, membrane tensile deformation, frame fracture and instability of shell plate are well simulated, and the impact acceleration curve is in good agreement with the test.

  Conclusions   The results herein can provide a verification reference for the impact simulation and analytical calculation of surface ship structure.