Identification of dynamic stiffness matrix of bearing joint region

Abstract

The paper proposes an identification method of the dynamic stiffness matrix of a bearing joint region on the basis of theoretical analysis and experiments. The author deduces an identification model of the dynamic stiffness matrix from the synthetic substructure method. The dynamic stiffness matrix of the bearing joint region can be identified by measuring the matrix of frequency response function (FRFs) of the substructure (axle) and whole structure (assembly of the axle, bearing, and bearing housing) in different positions. Considering difficulty in measuring angular displacement, applying moment, and directly measuring relevant FRFs of rotational degree of freedom, the author employs an accurately calibrated finite element model of the unconstrained structure for indirect estimation. With experiments and simulation analysis, FRFs related with translational degree of freedom, which is estimated through the finite element model, agrees with experimental results, and there is very high reliability in the identified dynamic stiffness matrix of the bearing joint region.

Dynamic parameters identification of rolling joints based on the digital twin dynamic model of an assembled ball screw feed system

“…The dynamic inertia coefficient w determines the influence of the particle's speed at the previous moment on the current speed, which is related to the population, denoted as w = w(t, N ). Generally, the particle's speed is limited to a certain range, as shown in equation (12). The v max determines the maximum flight distance in one iteration.…”

“…11 Therefore, accurately identifying the radial dynamic parameters of rolling joints in the ball screw feed system is also of great significance to improve the machining accuracy. Hu et al 12 deduced the stiffness identification model of bearing joint by the synthetic substructure method on the basis of theoretical analysis and experiments, and then identified the radial stiffness through measuring the frequency response functions (FRFs) of the lead screw in different positions as well as the whole structure. Dhupia et al 13 established parametric model of the dynamic parameters of the linear guide in the supported direction of the feed system based on Hertz Contact Theory and 2-dimensional Chebyshev polynomials.…”

Joints Parameters Identification in Numerical Modeling of Structural Dynamics

“…The updated quantities of rigidity, mass, or damping through such pair of -element can be solved by (12), (14), or (16). The updated quantities of rigidity matrices, mass matrices, or damping matrices through some pairs of local elements can be solved by general solution (11), (13), or (15).…”

“…In practice, the validation of finite element dynamic models was mainly through comparing experimental modal analysis results with analytical predictions [7]. Joint parameters could be experimentally determined by the frequency response functions measured, respectively, with and without the joints [8][9][10][11][12][13][14]. However, only use of natural frequencies in a model updating process is probably advantageous for a couple of reasons: (1) natural frequencies are usually more sensitive to the variations of model parameters, and (2) they are normally measured with higher accuracy in a modal test [15].…”

Cold Forging Process Analysis and Precision Progressive Die for Cam of Low-Carbon Steel

“…Moreover, considerable efforts and cost have been required for the powder metallurgy process, The cold forging is a precise deforming technology that suits to the mass production with high efficiency and can be taken as the final forming method [2][3][4]. Therefore, in this investigation, a new process to produce the cam based on cold forging technology was proposed to improve part qualities and process efficiencies, and the progressive die design of newly positon device was discussed [5][6][7].…”