Roof Grillage R2.

Research record

The detail behind
the study.

Source-linked work for this revision. Reported checks describe the stated model or test; physical qualification and applicability to the current retrofit remain separate.

Roof frame: shear-deformation sensitivity

The revised calculation includes bending, torsion and optional shear flexibility. It retains the candidate opening geometry and the full 661.115 kN roof-pressure resultant from the rounded Revision C envelope. Formal approval remains deferred.

These are sensitivity predictions, not approved limits or validated upper/lower bounds. The last mesh refinement changes the soft-case sampled maximum by approximately 0.025 mm. Equal sampled maxima in the other cases do not establish continuum or full-product convergence.

The independent benchmark checks a simply supported uniformly loaded beam against bending-plus-shear closed-form displacement and reactions, with both X and Y orientations. Whole-frame vertical equilibrium is checked separately. Numerical checks do not qualify assumed material properties or joint behavior.

The effective shear area is the combined area of the two vertical webs, with a sensitivity multiplier. Actual composite shear behavior, orthotropy, local distortion and joint compliance require further modeling and evidence. The model still omits wall thrust, geometric stiffness, local/global buckling, panel and closure response, joint peel/bearing, support compliance and environmental degradation.

linear-grillage.json contains all nine mesh/property cases, support reactions and element-end forces. sensitivity-summary.json compares the fine-mesh cases. Use these demands to develop joints and bearing interfaces; do not carry the earlier bending-only movement into a gasket or fabrication tolerance requirement.

Method references: Timoshenko stiffness formulation, Euler–Bernoulli reference.