Computer simulation of airplane landing onto water based on the Lagrange method

The dynamics of the airplane impacting on water was investigated. The Lagrange approach was employed to describe this fluid-structure interaction problem. The penalty method was employed to calculate contact force. The movement of airplane after landing was researched by analyzing the head and tail velocities; the structure response after landing was researched by different vertical velocities. The head and tail velocities change rapidly in the initial stage of entering water, then they keep stabilization. The stress wave transfer of airplane during landing was investigated, stress concentration appears at the tail and the middle of the plane successively, the tress transfers to other parts of plane gradually, stress concentration appears at the head of plane at last, its transfer is not clearly. The von Mises stress reaches the peak value in the initial stage, then it decreases rapidly, finally it keeps stabilization. The maximal structural deformation is achieved also in the hundreds milliseconds after landing, and then it relapses rapidly.