Midspan span load under Elastic Deflection

[Abrar_1512]

I have a beam fixed at both ends with tubular cross section, length 10m, yield strength 250Mpa, Dia 250mm, Wall thickness 5mm. I want to find the value of point load at centre for is elastic limit. Elastic Deflection will be Wl3/192EI and strain limit is 0.2% but how to find the maximum load at which the deflection is within elasticity of beam?

 

[robyengIT]

sigma_yield = Moment_max * y/Inertia

that is

250 = (W*L/8)*125/Inertia