Parametric Vibration Characteristics Extraction of a High-Power Turbo-Generator Anchor Bolt Utilizing Analytical and Finite Element Methods
پذیرفته شده برای ارائه شفاهی
کد مقاله : 1069-ISAV2025 (R1)
نویسندگان
گروه استاتیک
چکیده
In this paper the vibrational behavior of a turbo-generator (TG) anchor bolt is investigated, and its natural frequencies and mode shapes are evaluated by means of two different solution approaches including analytical and finite element (FE) methods. Firstly, the FE solution implemented, and then according to mode shapes, an appropriate boundary condition selected and applied in theoretical solution, and the results of two techniques are compared together. The modal FE analysis is implemented as pre-stress modal approach; because the modal eigenvalues are affected of axial stress resulted by tightening the anchor bolt. In this approach, prime a strength analysis is executed, and all connections, loads, boundary conditions, etc. are considered as their reality. Mesh controls and the other settings are applied properly, to reach the best run time and reliable results. In modal analysis, pre-process settings remained the same, and the contact status, and stress resultants are imported from strength analysis. In analytical method, governing equation is yielded based on Euler-Bernoulli beam theory. Then the natural frequencies, and mode shapes are extracted and explicated. Keeping a safe frequency margin from the excitation force, prevents from any oscillations when the device is running. In this study after vibrational analysis, the effective parameters are introduced, and sensitivity analyses versus important parameters are checked.
کلیدواژه ها
Title
Parametric Vibration Characteristics Extraction of a High-Power Turbo-Generator Anchor Bolt Utilizing Analytical and Finite Element Methods
Authors
Saeed Rostami, Peyman Shoreshi, Mohsen Nikfar
Abstract
In this paper the vibrational behavior of a turbo-generator (TG) anchor bolt is investigated, and its natural frequencies and mode shapes are evaluated by means of two different solution approaches including analytical and finite element (FE) methods. Firstly, the FE solution implemented, and then according to mode shapes, an appropriate boundary condition selected and applied in theoretical solution, and the results of two techniques are compared together. The modal FE analysis is implemented as pre-stress modal approach; because the modal eigenvalues are affected of axial stress resulted by tightening the anchor bolt. In this approach, prime a strength analysis is executed, and all connections, loads, boundary conditions, etc. are considered as their reality. Mesh controls and the other settings are applied properly, to reach the best run time and reliable results. In modal analysis, pre-process settings remained the same, and the contact status, and stress resultants are imported from strength analysis. In analytical method, governing equation is yielded based on Euler-Bernoulli beam theory. Then the natural frequencies, and mode shapes are extracted and explicated. Keeping a safe frequency margin from the excitation force, prevents from any oscillations when the device is running. In this study after vibrational analysis, the effective parameters are introduced, and sensitivity analyses versus important parameters are checked.
Keywords
turbo-generator, anchor bolt, finite element, analytical method, Modal Analysis