With the aid of Hu Washinzu variational principle, hourglass control is provided to suppress spurious modes via the assumed strain method, and the accuracy of the element is enhanced.

After a series of study of numerical method related to impact dynamics, such as the transient finite element discretization method of conservation equations, numerical quadrature and hourglass control, the identification and redefinition of sliding interface and so on, the dissertation is aimed at to study a high efficient.

According to the ratio of kinematic energy to internal energy and the ratio of hourglass energy to internal energy,a criterion of virtual punch velocity selection wasproposed.

The experimental results show that the equal axial ultrafine microstructures can be introduced to the bulk test material during sandglass extrusion.

In this paper we did experiments on ingot Zn\|5%Al alloy,to find the effect of sandglass extrusion technology on the microstructures and properties of the test mate.

The computation region of the sand funnel is treated by special means so that some reasonable boundary conditions can be adopted.

Combining the theoretical analysis and the existing experimental achievement,the important role of secondary flow for sediment ejection in sand funnel is researched for the first time.