Section 4. Inelastic and composite beams 4.1. Bending of inhomogeneous cross section 4.2. Shear of inhomogeneous cross sectio 4.3. Composite cross section 4.4. Cracking moment 4.5. Deflection of RC beam 4.6. Moment resistance of RC cross section 4.7. Effect of compressed steel bars in elastic stage 4.8. Effect of compressed steel bars on plastic resistance 4.9. Eccentrically compressed masonry walls 4.10. Shear resistance of masonry walls 4.11. Stresses of soil under square foundation 4.12. Elastic and plastic reistance of circular cross sections 4.13. Failure envelop