In this study, three IEA Wind 15MW offshore reference wind turbines with monopile support structures, are placed at a distance of eight rotor diameters in the prevailing wind direction. FAST. Farm responses are simulated under different wind conditions and sea states. The outputs suggest that for downstream turbines the effect of partial wake impingement is higher on tower bending moments than on blade bending moments. The downstream wind turbines have higher energy spectra around the tower natural frequency, which may potentially affect the fatigue loads and cut down the turbine lifetime. This study provides references for structural load analysis of downstream wind turbines in large-scale fixed-bottom offshore wind farms.