Bringing in definitions

A design office does not want the elastic modulus of steel typed into forty worksheets, each free to be wrong on its own. use brings in a pack: a curated set of definitions that lives in one place and arrives by name.

use steel

use constants

The definitions a pack brings are not shown — a worksheet that shows its work should show the work its author did, not fourteen constants nobody typed. nomo packs lists what each one holds.

A bracket in A992, checked against its grade

M

4.2 kip \cdot in

S

0.42 {in}^{3}

σ

\frac{M}{S}

\frac{474.536 J}{6.88257 \times 10^{−6} m^{3}}

68947600 Pa

σ_{allow}

0.6 \cdot {Fy}_{A992}

0.6 \cdot 50 ksi

206843000 Pa

σ

10 ksi

σ_{allow}

30 ksi

check

σ \leq σ_{allow}

68947600 Pa \leq 206843000 Pa

pass

The self-weight of the same section

Density comes from steel and standard gravity from constants, which is what makes them worth having in one place: neither is a number this worksheet should be asserting.

A

6.5 {in}^{2}

w_{self}

ρ_{steel} \cdot g_{earth} \cdot A

7850 m⁻³·kg \cdot 9.80665 {m·s}^{−2} \cdot 0.00419354 m^{2}

322.828 {kg·s}^{−2}

w_{self}

22.1207 lbf/ft

A pack's names are visible everywhere in the worksheet

They are global definitions, so where the use line sits does not change what the worksheet means — the same rule as any other global.

E_{ratio}

\frac{E_{steel}}{G_{steel}}

\frac{200 GPa}{77 GPa}

2.5974