This is a Javascript calculator to compute the defection of hollow rectangular beams. It assumes the beam is supported on one end and the force is applied to the other end perpendicular to the width. (Like a diving board) Bending stress is also calculated. If bending stress exceeds the materials yield strength it will be permamently deformed and not return to its original shape. Enter the length, width, height and wall thickness and then select the material from the drop down menu. Click COMPUTE and read the deflection value in the output panel.
The formula is: Deflection =W*L^ 3/ 3*E*I Where W is force, L is length, E is Modulas of Elasticity in psi, and I is Second Moment of Inertia. Moment of inertia is calculated by ((width * height^3)  (inside_width * inside_height^3)) / 12 .
Bending stress is computed by: (Force*Length) / (I / (0.5*height))
