====== Buckling in FE simulations ======

[[https://en.wikipedia.org/wiki/Euler%27s_critical_load|Buckling what?]]
===== Euler column buckling =====

base model: {{ :wikifemfuchde2019:400mm_supported_bar.mfd |}}
{{ :wikifemfuchde2020:400mm_supported_bar_worked.mfd |}}
{{ :wikifemfuchde2020:perturbed400mm_supported_bar.mfd |}}
{{ :wikifemfuchde2020:perturbed400mm_supported_bar_worked.mfd |}}

buckling load theoretical evaluation: {{ :wikifemfuchde2019:400mm_supported_bar.wxmx |}}


steps:
  * nonlinear loadcase, unperturbed ([[https://en.wikipedia.org/wiki/Newton%27s_method|N-R method]])
  * preloaded structure natural modes
  * nonlinear loadcase, perturbed
  * linearized pre-buckling analysis


===== Flexural-torsional buckling example =====

{{ :wikifemfuchde2019:simplisupportedprofile_v000.mud |}}

{{ :wikifemfuchde2020:simplisupportedprofile_v001.mud |}}

profile made in s235jr steel

thickness:
{{tablelayout?rowsHeaderSource=Auto}}
^                            ^ thickness  ^
| flanges                    | 4 mm       |
| web                        | 2mm        |
| gusset plates at supports  | 4 mm       |

simply supported in the vertical (//y//) direction the at gusset plate - lower flange intersection nodes (''support_me'' node set).

100kN load, uniformly distributed along the intersection line between the upper flange and the web spanning from support to supports (''load_me'' node set).
Please note that in MSC.Marc the supplied point load value is applied to **each** associated node.

Evaluate the peak equivalent von Mises stress along the structure according to the linear elastic modeling.

Due to the compressive state of the profile web, a check with respect to buckling is also required.

===== Post-buckling analysis of a complex structure =====
{{ :wikipaom2018:piramide_buckling_base.mfd |}}

{{ :wikipaom2018:piramide_buckling_neotiranti.mfd |}}

{{ :wikipaom2018:piramide_buckling_neopannelli.mfd |}}