Big Beam LVL or Glu Lam load capacity to support a gymnast

If you can approximate it as isotropic material, then you can use Euler beam theory to find the stress and compare it to the yield stress:

$ sigma = My/I$

• $ sigma $ = normal stress

• $ y $ = distance from neutral plane (midplane of symmetric section beam). Maximum stress occurs at the outside edge so use $y=h/2$ where $h$ is the height of the beam (12 in).

• $ I $ = 2nd moment of area of the section about the axis perpendicular to y and also in the plane of the section. For a rectangular section, $I=b h^3/12$. $b$ is the width of the beam. For other shapes like I-beam, see Google.

• $ M $ is the bending moment. For a simply-supported beam (is it simply supported?) with point load at the center, the bending moment at the center (where it's maximum), is $ M = FL/4 $. $F$=load (1000 lb_f) and $L$ = length (20 ft).

Beware that there might be other failure modes too.