Question

Beams require _____ inches of solid bearing at each support point if resting on concrete or masonry, and _____ inches if resting on wood or metal.

Answer 1

To design a structure with a constant length difference of 0.500 meters between a steel beam and an aluminum beam, the engineer must calculate the initial lengths based on the specific coefficients of thermal expansion for the materials and the expected temperature range.

Step-by-step explanation:

A student needs to design a structure where the difference in length between a steel beam and an aluminum beam remains constant at 0.500 meters regardless of temperature changes. To achieve this, the engineer must consider the coefficients of thermal expansion for steel and aluminum, as well as the range of ordinary temperatures the structure will be exposed to.

If we let αsteel represent the coefficient of thermal expansion for steel, αaluminum for aluminum, Lsteel the initial length of the steel beam, and Laluminum the initial length of the aluminum beam, then the design condition can be expressed as:

Laluminum + αaluminumΔT Laluminum - (Lsteel + αsteelΔT Lsteel) = 0.500 meters

For any given temperature change ΔT, the lengths can be calculated so that this condition is met.