Question

Problem 5.1. Axial stress in a reinforced box beamm Figure 5. 12 depicts an aluminum rectangular box beam of height ћ-0.30 m, width b-0.15 m, flange thickness ta-12 mm, and web thickness tw-5 mm. The beam is reinforced by two layers of unidirectional composite material of thickness te - 4 mm. The section is subjected to an axial load i - 600 kN. The Young's moduli for the aluminum and unidirec- tional composite are Ea - 73 GPa and Ec140 GPa, respectively. (1) Find the distribution of axial stress over the cross-section and sketch the distribution around the perimeter of the section. (2) Find the magnitude and location of the maximum axial stress in the aluminum and composite layers. (3) Sketch the distribution of axial strain over the section. How does it vary over the full cross-section? (4) If the allowable stress for the aluminum and unidirectional composite are ơallow-400 MPa and ơallow-1500 MPa, respectively, find the maximum axial force the section can carry t,工 Fig. 5.12. Cross-section of a reinforced rect- angular box beam

Answer 1