A simple model was constructed to convince the analytical solution and a numerical results.
For instance, the instability of an Euler column was investigated under uniform pressure with magnitude equal to 1 on the top surface. The FEM calculation (Abaqus) exhibits that the eigenvalue for mode 1 is negative and the minus value cann't be transformed to positive though I have try to variate the mesh size and category as well as calculative measures with Lanczos or subspace.
BTW: the step for this model is applied with Buckle in Linear perturbation
It will be the most delightful to attain an instruction.
Thanks in advance!
Detailed explanation: the
Detailed explanation:
the base feature of the model is: 3D, deformable,and solid, which will induce negative eigenvalue at mode 1
if i choose the model with 3D, deformable,and wire( the dimension of the across section is same with the above), the numerical results are consistent with the analytic consequence.
Anyone could help me?