Experimental analysis of dynamic behavior of hot forging proccessed shafts

Rotating shaft system is employed in a wide variety of industrial applications including automobiles, machine tools, and machinery. The performance of any rotating shaft system is very dependent on vibrations generated by the shaft. The dynamic behaviors of a rotating shaft system are influenced by a number of parameters which include shaft material, the system geometry, inertial properties, and the mass and stiffness distribution of the rotating assemblies. The selection of the shaft material is crucial to meet the enormous demand of industrial users on the capability of vibration resistance of the rotating shaft system. Incorrect shaft material selection can lead to system failure. Treatment of material has received much attention over the last few decades. The studies to date have headed to focus on material properties for resistance and strength rather than dynamic behavior. On the other hand a substantial amount of extant literatures have reported on dynamics behavior of rotating shaft system regardless shaft material. Because of its fundamental importance in the rotating shaft systems, rotating shaft dynamics will persists as an active area of study for foreseeable future. The main objective of this study is to experimentally show that the material properties of shaft have a significant influence on the vibration response within operating range of the rotating shaft system. The role of rolling, forging, and tempering treatments to AISI 4140, AISI 4340, and AISI 5140 steel shaft effects on the rotating shaft system dynamic behavior is investigated. Treatable AISI 4140, AISI 4340, and AISI 5140 steel are among the most widely used in industrial applications requiring more resistance and strength. Rolling, rolling and forging, rolling and tempering, and rolling, forging, and tempering treatments are utilized to sustain the service life by increasing vibration reliability for each of AISI 4140, AISI 4340, and AISI 5140 steel shaft materials. Since treatments of shaft material play a very important part in stability of rotating shaft, four different treatments are employed. The results showed that rolling treatment surprisingly and positively affects the dynamic behavior of AISI 5140 steel shaft compare to AISI 4140 and AISI 4340 steel shaft with rolling, rolling and forging, rolling and tempering, and rolling, forging, and tempering treatments. It can be concluded that the performance of the rotating shaft system is very dependent on vibrations generated by the rotating shaft subject to properties of its material.