Capability In The Research Of High Strength Hydraulic Bolt For Marine Shafting System

Hydraulic bolt is a novel type of joint part for the application in shaft flange of modern ship, especially used in the case of high strength and large torque for shaft system of military vessels. It overcomes the shortcoming of the traditional hinge bolt system, and meets the requirement of the high-intensity performance of bolt materials for shaft system; it has been a new revolution of connector. It is of great application and economic values to perform research on this subject, beneficial reference can also be provided for domestic research in this field.In this thesis, on the basis of force analysis of hydraulic bolt, starting from the Lame formula in Elasticity, the elastic model of hydraulic bolt is developed in which the state of hydraulic bolt, sleeve and flange are all taken into account. Strength analysis of hydraulic bolt and sleeve structure and force analysis of bolt hydraulic are all theoretically analyzed. The optimal preload is also investigated analytically. A set of accurate and reliable hydraulic bolt design formulas are presented, software which is extremely convenient for the practical application is established. Based on the investigation on design, experiments on tension, assembly and disassembly, shear and materials performance test are all carried out on hydraulic bolts of which diameter is 90mm, then the validity of the theoretical design have been verified. In addition, some useful reference will be provided for the engineering application.Using of nonlinear contacting analysis approach, according to the structure feature of hydraulic bolt, the plane and space 3-D finite element analysis of hydraulic bolt are conducted by ANSYS software, then the correctness of theoretical analysis is verified. Analyzing the simulation data through comparison, suggestion for improvement of the hydraulic bolt structure has been proposed.Studies presented in this thesis show that: at the optimal preload, anti-shear torque is about 95 percent of the total for hydraulic bolts, and flange surface frictional torque accounts for about 5 percent of the total; In the elastic range, the maximum gap between sleeve and flange hole can be 0.18% D (did not consider the surface roughness effects); Non-linear 3D finite element analysis of hydraulic bolt is achieved for the first time, can supply a more realistic and effective analytical method for domestic research in this field; some experiments are also performed to study the performance of hydraulic bolts, they will piay a important significance role in the engineering scene.