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Based on ANSYS/LS-DYNA code, the finite-element models were created to simulate the response of the aircraft panel structure impacted by high velocity projectile. The models proved to be effective through the comparison between the results of simulation and relative experiments. Then the impact process was simulated respectively considering the states of various types of stress in the panel. Through analyzing the simulation results, the influence of various stress states in the panel on impact response and damage mechanism was summed up. The conclusions indicated that the stress and particularly compression stress in aircraft panel structure can facilitate much more deformation and damage when the panel suffers high velocity impact.

The electronic structure of ZnO is calculated by using an accurate full-potential linear plane-wave based on the density function theory and WIN2K package. The curves of energy band and density of states of ZnO are gained. The energy gap is 0.9eV that is better some of the computed results by theory approaches and smaller than the experimental value obtained by X spectra. After analyzing it is known that the coulomb repulsion between 3d state of Zn and 2p state of O is very strong leading to the increase in the energy of O2p and the energy gap become smaller.

In order to research the aircraft impact damage, one symbolic fitting method for analyzing and forecasting the damage data is proposed based on genetic programming (GP). The method can be used to forecast the impact damage by recognizing the rule in some groups of actual data including impact parameters and damage hole size. The principle of GP symbolic fitting method is briefly introduced. The fitting model is created with some sample data respectively for training and testing from Sorenson experiential equation. The computation with Matlab program indicates the model has a good performance to fit and forecast the damage data with avoiding the noise. The application of GP symbolic fitting method can help to decrease the times of fire experiments. Since the method can recognize the complicated nonlinear relationship between the impact parameters and damage data, it is more applicable than theoretical analysis and experiential equation to forecast the aircraft impact damage.

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