Maximum deflection: D = (Fx(L)cubed)/(76.8xExI)
Wall thickness X 50%: D= (Fx(1.14L)cubed)/(76.8xEx1.5xI)
Steel beam at 10% I: D = (Fx(1.98 L)cubed)/(76.8xEx7.8xI)
I = moment of Inertia, D = deflection, F = uniform load, L = beam length: Diagram Available
Conclusion: Increasing wall thickness is an inefficient method to increase bending strength in vinyl windows. However, weld strength, impact resistance, and screw hold will limit minimum thickness.
(c)1989 Plastmo Ltd.
