NONLINEAR ANALYSIS OF COMPOSITE STEEL-CONCRETE BEAMS UNDER COMBINED FLEXURE AND TORSION

With prescribed generalized coordinate, the differential equation system for restrained torsion analysis of composite beams is established based on the principle of generalized coordinate method. An extension spring and a slipping spring are introduced to simulate the effect of detachment and slippage on the interface between concrete slab and I-shaped steel beam. The solver of ordinary differential equations (ODEs)--COLSYS is employed to solve the system equations. A practical example is studied to demonstrate the method.