Study On Static Contact Behaviors And Dynamical Characteristics Of Wedge-Ring Connection Structure

Wedge-ring connection, has been gained some practical utilizations in some specific structures, such as torpedoes, mines, for such connection form, comparing with bolt connection, tube nipple connection, possesses some advantages of making connection surface of the shells smoother, case size smaller, additional mass lighter, connection structure tighter, assembly processing simpler and disassembling more convenient. Wedge-ring connection structure is a multi-deformable-body combined structure with its components contacting with each other, and the nonlinear factors in it are physical, geometrical, contact, clearance, dissipative, motive nonlinearities, which makes the mechanical behaviors of the structure far more complicated than linear ones. Consequently, to study and illustrate the mechanisms of the phenomena in nonlinear mechanics, to research the corresponding numerical calculating methods, not only have an important scientific significance for the development of mechanics, but also possess an important practical engineering value by supplying a theoretical support for the design and use of the structure. In this paper, the nonlinear static contact behaviors and dynamic characteristics of a wedge-ring connection structure are studied by theoretical analysis, finite element (FE) numerical simulation and experimental approaches. These studies span a wide variety of applications (form nonlinear static contact behaviors of the structure to nonlinear vibrations and shock response of the structure with contact feature), and solve a series of technical difficulties meeting with in the course of static and dynamic analysis of the structure (from parametrical identifications of a simplified single degree of freedom dynamic model to studies on the nonlinear static behaviors and dynamic responses of a three-dimensional (3D), multiple-component assembly featuring structure). Some important conclusions are obtained, and these conclusions give some available references for the theoretical analysis, numerical simulations and experimental studies of the wedge-ring connection structure and other similar complex structures, and provide some valuable technical supports for the design and use of engineering structures.Firstly, the developments of the nonlinear contact theory and the studying actualities are summarized, then the advances of the static contact behaviors, the FE numerical simulations of the vibrations and shock responses of the connection structures are simply introduced, the studies on the modeling and parameter identifications of the nonlinear systems are synthesized, and some previous achievements on the theoretical analysis, FE numerical simulations, experimental studies, and the designs and uses of the wedge-ring connectionstructure are surveyed and reviewed as well. The basic theories of nonlinear FE on the static contact questions are given in Chapter 2, the mathematical descriptions in the form of integral and the iteration equations in the discrete form of the contact equations are given.The mechanical behaviors of the wedge-ring connection structure with deformable contact under uniaxial tension load are studied by the methods of FE numerical simulations, theoretical analysis and experimental studies in Chapter 3. In the experimental studies, the strains are recorded using resistance strain gages, the in-surface displacements and off-surface ones of the connection location of the structure are measured using laser holography, and the load vs. total displacement curve is recorded by the measuring system of the MTS810 Material Test Machine. A 3D FE model with deformable friction contact of the wedge-ring connection structure is constructed for calculating the axial and circumferential stresses at the connection location of the structure, and simulating the breakpoint occurring on the load vs. displacement curve. The experiment and FE numerical calculations indicate that the quasi-symmetric property of the wedge-ring connection structure causes asymmetric deformation. The larger the axial loads an...