Rectangle geometry vs material stiffness

A $200\text{ mm}\times400\text{ mm}$ rectangular section is assigned two different elastic moduli. Compute the geometric properties first.

Isotropic shear modulus

For a linear isotropic material with $E=200{,}000\text{ MPa}$ and $\nu=0.30$, calculate $G$.

Thin-walled open-section torsion screen

An idealized built-up open section consists of two $200\times15\text{ mm}$ flange strips and one $300\times10\text{ mm}$ web strip. Estimate the Saint-Venant torsional constant using the thin-rectangle approximation.

Beta-angle / orientation diagnosis

A rectangular or I-shaped member appears to bend about its weak direction under a lateral load even though the physical design intended strong-axis bending.

Truss idealization vs end releases

A roof-truss web is intended to carry axial force only. Should the model rely on many manually assigned moment releases or use an axial/truss member idealization?

Concrete elastic modulus is a design-basis input, not a universal strength conversion

A project needs an elastic modulus for a concrete analysis model. How should an empirical code equation be used?