This paper presents the vibration control problem of the single-link flexible composite manipulators. Two different materials of composite which are epoxy-glass and carbon-fiber are considered for both simulation and experimental analyses. Manipulators are obliged to perform a job such as pick and place applications and machining a workpiece. Therefore, a payload is attached to the manipulators. If the system is suitable for loading applications, the improved vibration control method is used to suppress the residual vibrations of the manipulators. The simulation results are verified with experimental results and it is observed that the proposed vibration control method significantly reduces the residual vibrations compared to passive vibration control method in literature. Additionally, the stresses during motion are analyzed for both simulation and experiment and the effectiveness of the proposed method on the stresses is investigated. Results showed that only the carbon-fiber manipulator is suitable for payload applications and its utilization efficiency can be greatly improved by the proposed method.