This study uses three-dimensional finite element models to simulation composite beams with simple (shear) connections subjected to combined gravity and thermal loads. A partial floor assembly is modeled including the columns, beam, slab, wire mesh, shear studs, and connection to applicably apply forces to the connection that are present during real building fires. Three different simple (shear) connections are modeled: shear-tab, single-angle, and double-angle connections. Varying geometric parameters (coped bottom flanges, slotted holes, and a metal deck); fire resistance ratings (1hr FRR, 2hr FRR); and fire loading scenarios (1hr fire with cooling, 2hr fire with cooling, ASTM E119 fire) are simulated to determine cost effective solutions to improved fire performance of composite beams with simple connections. The results of these simulations showed that the cooling phase of a fire creates large axial tensile forces in the connections which can cause damage. However, the composite beams with simple connections did not collapse during a 1hr or 2hr fire with cooling with appropriate FRR.