4. A structural engineer must determine which type of steel to select for a beam, but the
weight limitation cannot exceed 7 tons. The project has narrowed the choices down to
A36 steel (p= 7800 kg/m³) and A992 steel (p= 7850 kg/m³). However, the engineer
needs to determine the load difference between an A36 and A992 steel box beam with an
inertia of 356 in, and has an elastic modulus of 30 x 106 PSI & 35 x 106 PSI, respectively.
The A36 steel is designed to deflect 0.107" while the A992 steel is designed to deflect
0.118". Both beams have a span length of 12.3 meters, a distributed stress of 101.45
kN/m², full length of 15.78 m, and the beam is in a simple load configuration. Determine
the load difference between the two beam options at the design limit.
What is your calculated answer most closely to?
a. 1.5 ton
b. 20.5 tons
c. 104.7 tons
d. 8924.1 tons