Effective Moment of Inertia of a Reinforced Concrete BeamNOTE: Because reinforced concrete...

Effective Moment of Inertia of a Reinforced Concrete Beam

NOTE: Because reinforced concrete beams crack due to tensile stresses created by moment and shear, initial elastic deflections are based on an empirical equation for moment of inertia established from experimental studies of full-size beams (provided in the ACI Code). This equation produces an effective moment of inertia I_e that varies from about 0.35 to 0.5 of the moment of inertia I_G based on the gross area of the cross section. The additional deflection due to creep and shrinkage that occurs over time, which can exceed the initial deflection, is not considered.

Using a finite summation, compute the initial deflection at point C for the tapered beam in Figure P8.43. E = 24 GPa. Base your analysis on the properties of 0.5I_G.

Figure P8.43: