Finite strain and stability · VNV-TET4-TL-BUCKLING-002

TET4 linearized buckling refinement

A fixed-free column study tracks the critical eigenvalue as a linear TET4 mesh is refined and compares one case with CalculiX.

Research scope · discretization trend onlyCampaign version 0.2.0

Read the recorded results ← All calculation cases

TET4 buckling critical load against mesh refinement with CalculiX and Euler references. — Critical load trend through the 98,304-element refinement. The plotted load unit is not stated in the source report.

Recorded values

Main observables and references

Values come from the linked campaign record. Acceptance thresholds are shown separately from observed results.

QF Solver critical load818.415402Largest recorded mesh; source does not state units

CalculiX critical load818.696000Same connectivity; source does not state units

Relative QF / CalculiX difference0.0343%Largest mesh

Relative difference to Euler reference1.896%803.190462, source unit not stated

Model and execution

What was calculated?

A weak preloaded state is used to obtain the geometric stiffness contribution.
The first critical load is compared with the Euler fixed-free reference of 803.190462 in the source report.
The largest plotted mesh contains 98,304 TET4 elements and 56,355 degrees of freedom.

How to read the evidence

What the results say

At the largest mesh, QF Solver reports 818.415402 and CalculiX reports 818.696 on the same connectivity. The relative difference is 0.0343%.
QF Solver remains 1.896% above the Euler reference at the largest level. The source attributes the slow approach to linear tetrahedron bending discretization.
The source does not declare the load unit, so the reported values are shown without an inferred unit.

Additional figures from this calculation

Select a figure to inspect it at full size. Captions state the quantity, comparison and any display amplification available in the source.

First TET4 tangent buckling mode with initial and amplified modal shapes. — First tangent buckling mode. The mode display is normalized and amplified for visibility.

Scope boundary

Where this case stops

Buckling remains a research scope in this case; a close same-mesh correlation does not qualify the critical load.
The report compares the eigenproblem with CalculiX; it does not claim a matching Code_Aster solid buckling operator.

Open the calculation method

These white box sheets explain the element, constitutive law or numerical method used by this case.

White box sheetTET4 element formulation White box sheetLinearized buckling pencil White box sheetSt. Venant–Kirchhoff law

Reproduce and inspect the source

The source paths below are pinned to one repository commit. Opening the current site does not rerun the original calculation.

Controlled V&V reviewdocs/verification/tet4_total_lagrangian_structural_v2.mdBuckling campaign scriptscripts/run_tet4_tl_buckling_vnv.pyMesh refinement scriptscripts/run_tet4_tl_buckling_refinement.py

Figure and source snapshot e367fe58b2b9ebb4aef321424ca775e80e82d9ca. Campaign execution version: 0.2.0. Current site release and original calculation version identify different events.

Related cases

Other recorded calculations in this family.

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