Multiobjective Of Buffer Absorbing Energy Optimization For Foam-filled Thin-walled Structures Subjected To High Gvalue Impact

In high speed hard target penetration of projectile and projectile explosive dispersion process missile control circuits will withstand the impact acceleration effect of tens of thousands of g which has far beyond the bearing range of the test circuit and needs buffer to protect control circuit modules. Under the axial impact, thin shell structure through the plastic deformation can be very good to play the role in buffer energy absorption. However, the average load of the structure in the compression process is relatively small, the energy absorption efficiency is not enough. Foam metal have some advantages, such as small density, strong shock absorption and so on, can be compressed in a certain stress platform to produce a larger deformation, so it play the important role in the buffer energy absorption. But the stress platform of the foam aluminum is so lower, the cushioning effect is limited, so it is not suitable for the load bearing structure alone. Therefore, the aluminum foam-filled shell structure present, it can give full play to the advantages of the two materials, make up the lack of material in the energy absorption.In order to reduce the initial load peak, In this paper, propose a shell structure with induced indentation.Using explicit dynamic finite element software LS-DYNA, by considering the 4 factors, the shock isolation efficiency, acceleration response stability, the total absorption and structural compression unit displacement energy absorption to analyzing the number of indentation and the shape of indentation in energy absorption effect of the structure. Results show that V2 structure shock isolation efficiency was the highest, reaching the 71.0%, has three indentation of the shell structure shock isolation efficiency is relatively low, even lower than the no indentation structure. The structure acceleration response instability degree increased with the increasing number of indentation, the acceleration curve becomes smooth, not conducive to the protection of the buffer. The energy absorption increases with the increase of the number of impressions, and the total energy absorbed of the structure is determined by the displacement of the compression unit and the collapse displacement.Because the single shell structure in energy absorption less than the filling structure, and in order to get the energy absorbing filling shell structure with good performance. Multi objective optimization design of aluminum foam filled shell structure based on surrogate model technology. In this paper, polynomial response surface and radial basis function two approximate agent model are proposed, through a full factorial experimental design method selected sample points, using LS-DYNA finite element technique to obtain the design sample point collision information to construct agent model of approximate expressions. Finally use ideal point method and NSGA-II algorithm for multi-objective optimization problem is solved.