Simulation On Constrained And Dynamic Buckling Of Structure

This thesis explains the explicit dynamic finite element theory, and numerical analysis of buckling was made to the structures by ANSYS/LS-DYNA and PAMCRASH. This thesis contains three parts:The first part focused on the simulation of the dynamic buckling for rod impacted by dynamic force and rigid body in axial direction, which is hinge joint and uniform cross section, basing on the ANSYS/LS-DYNA and PAMCRASH. The influence of the stress wave was considered in the whole process of the dynamic buckling. It is validated that each order critical force of dynamic buckling is close to the Euler critical force under the static force. The dynamic buckling may excitated multiple modes under a little time dynamic force. The effect of the mass and velocity and momentum of the rigid body on each buckling characteristic parameter was also discussed when the rod was impacted by the rigid body with different mass or different velocity.The second part focused on the numerical analysis of constrained buckling for the thin rectangular plate (delamination of composite) which is affected by fiber bridges, by ANSYS and PAMCRASH. The effects of the stiffness and the distribution of the unbroken fiber on some buckling characteristic parameter, such as critical force and buckling mode and characteristic length and so on are taken into account.The third part was mainly about the simulation of the honeycomb by using PAMCRASH. The compression and the shear test of the honeycomb with and without pre-compacted were simulated, whose numerical result was compared with the experiment's. And the results between the compression and the shear test, with and without pre-compacted respectively, were also compared. Some useful conclusions are achieved.