文档介绍：dyna沙漏控制（该沙漏控制）
1. definition of hourglass
Hourglass hourglassing generally occurs when a reduced integration unit is hell units, the hourglass energy density cloud can be plotted, but SHGE=2 is set in advance in the *database_extent_binary card. Then select Fcomp>Misc>hourglass energy in LS-Prepost.
2. hourglass control method in LS-DYNA
refine the model mesh: good modeling prevents the generation of excessive hourglass: the basic principle is the use of a homogeneous mesh, (in general, the overall mesh refinement significantly reduces the effect of the hourglass.)
avoiding concentrated loading on a single point: due to the activation of the unit the hourglass modes to the adjacent unit, so the loading should be extended to a surface composed of several adjacent nodes, the pressure load is better than in single point loading.
use the full integration unit: This is a complete way to eliminate the hourglass, [but they cost more CPU time than other cell algorithms, and for some incompressible behavior, metal plasticity and bending problems, they can lead to unrealistic stiffness results (locking).]
the internal hourglass control of the software: follows.
ANSYS/LS-DYNA provides some internal hourglass controls. The idea of these methods is that..:
The internal hourglass control of software:
increase the stiffness of the hourglass model, but not the rigid body motion and