Heng Liu

Bio: Heng Liu is an academic researcher from Xi'an Jiaotong University. The author has contributed to research in topics: Rotor (electric) & Bearing (mechanical). The author has an hindex of 9, co-authored 57 publications receiving 299 citations. Previous affiliations of Heng Liu include General Electric.

Dynamic modelling for vibration analysis of a cylindrical roller bearing due to localized defects on raceways

Abstract: The current study presents a multi-body dynamic model for investigating the vibration responses of a cylindrical roller bearing with localized surface defects such as dents on raceways. This model ...

Investigation on the stability and bifurcation of a rod-fastening rotor bearing system:

Abstract: The stability and bifurcation of a flexible rod-fastening rotor bearing system (RBS) is investigated in this paper. The rod-fastening rotor has two kinds of special structural features – rods and interfaces. The circumferentially distributed rods are modeled as a constant stiffness matrix and an add-on moment vector, which is caused by the unbalanced pre-tightening forces. The stiffness matrix of interface is composed of normal and tangential contact stiffness, which are determined by the pre-tightening forces. After the shaft is discretized by Timoshenko elements, the system is reduced by a component mode synthesis. Periodic motions and stability margins are obtained by using the shooting method and path-following technique, and the local stability of system is obtained by using the Floquet theory. Comparisons indicate that the rod-fastening and complete RBS have a general resemblance in the bifurcation characteristics when mass eccentricity and rotating speed are changed. The unbalanced over-tightening ...

The Design and Analysis of Experiments

Abstract: THE DESIGN AND ANALYSIS OF EXPERIMENTS. By Oscar Kempthorne. New York, John Wiley and Sons, Inc., 1952. 631 pp. $8.50. This book by a teacher of statistics (as well as a consultant for \"experimenters\") is a comprehensive study of the philosophical background for the statistical design of experiment. It is necessary to have some facility with algebraic notation and manipulation to be able to use the volume intelligently. The problems are presented from the theoretical point of view, without such practical examples as would be helpful for those not acquainted with mathematics. The mathematical justification for the techniques is given. As a somewhat advanced treatment of the design and analysis of experiments, this volume will be interesting and helpful for many who approach statistics theoretically as well as practically. With emphasis on the \"why,\" and with description given broadly, the author relates the subject matter to the general theory of statistics and to the general problem of experimental inference. MARGARET J. ROBERTSON

The concept and progress of intelligent spindles: A review

Abstract: Intelligent spindles are core components of the next-generation of intelligent/smart machine tools in the Industry 4.0 Era. The purpose of this paper is to clarify the concept of intelligent spindles and provide an in-depth review of the state-of-the-art of related technologies. A new integrated concept for intelligent spindles is proposed, followed by descriptions of required characteristics, key enabling technologies and expected intelligent functions. Relevant research that may be beneficial to the development of intelligent spindles is reviewed from six thrust areas, which include monitoring and control of tool condition, chatter, spindle collision, temperature/thermal error, spindle balance, and spindle health. Finally, current limitations and challenges are discussed, and future trends of intelligent spindles are prospected from various perspectives.