Tài liệu Kỹ Thuật - Công Nghệ

Multiple crack identification in stepped beam by measurements of natural frequencies
In the present study the well known Rayleigh Quotient has been developed for multi-stepped beam with arbitrary number of cracks and boundary conditions. This is an explicit expression of natural frequencies in term of crack parameters that provides a simplified method for calculating natural frequencies of the beam. Moreover, the Rayleigh Quoti...
16 trang | Chia sẻ: huongthu9 | Ngày: 12/08/2021 | Lượt xem: 515 | Lượt tải: 0
Free vibration analysis of four parameter functionally graded plates accounting transverse shear mode
Classical, symmetric and asymmetric profiles are generated by the suitable assumption of value of power law parameters. It was noticed symmetric profiles exhibits maximum frequency value for certain value of power law exponent (p > 1) and this tendency is irrespective of the plate thickness and boundary condition. Variation of single parameter in ...
18 trang | Chia sẻ: huongthu9 | Ngày: 12/08/2021 | Lượt xem: 518 | Lượt tải: 0
Parameter optimization of tuned mass damper for three-Degree-of-freedom vibration systems
In this paper, the sequential quadratic programming (SQP) method is used to calculating parameter optimization of the tuned mass damper (TMD) for three-degree-offreedom vibration systems. The following concluding remarks have been reached: - If the TMD is attached to the vibration source (excited force or kinematical excitement), the effect of vib...
12 trang | Chia sẻ: huongthu9 | Ngày: 12/08/2021 | Lượt xem: 414 | Lượt tải: 0
Spectral analysis of multiple cracked beam subjected to moving load
load the cracks occurred to symmetric positions affect not symmetrically on the response; amplitude of forced vibration is not monotony increasing with growing number of cracks. The proposed method can be used for dynamic analysis in the case of more complicated moving load and crack detection problem by measurement of dynamic response of beam-l...
12 trang | Chia sẻ: huongthu9 | Ngày: 12/08/2021 | Lượt xem: 489 | Lượt tải: 0
A direct evidence of fatigue damage growth inside silicon mems structures obtained with ebic technique
In this study, EBIC technique was applied successfully to observe the growth of defects inside silicon MEMS structures. The changes of local contrast were successfully observed at the notch tip of the specimens, which remained the same through the hydrofluoric acid treatment after the experiment. The damage, which caused the local contrast change...
12 trang | Chia sẻ: huongthu9 | Ngày: 12/08/2021 | Lượt xem: 467 | Lượt tải: 0
An analytical approach to analyze nonlinear dynamic response of eccentrically stiffened functionally graded circular cylindrical shells subjected to time dependent axial compression and external pressure - Part 1: Governing equations establishment
A formulation of governing equations of eccentrically stiffened functionally graded circular cylindrical thin shells subjected to time dependent axial compression and external pressure based upon the classical shell theory and the smeared stiffeners technique with von Karman-Donnell nonlinear terms is proposed in this paper. An approximate three...
16 trang | Chia sẻ: huongthu9 | Ngày: 12/08/2021 | Lượt xem: 450 | Lượt tải: 0
An analytical approach to analyze nonlinear dynamic response of eccentrically stiffened functionally graded circular cylindrical shells subjected to time dependent axial compression and external pressure - Part 2: Numerical results and discussion
The nonlinear second-order differential three equations system (36-38) in Part 1 is solved by using the Runge-Kutta method and applying the Budiansky-Roth criterion to analyze the nonlinear dynamic response and critical dynamic buckling load. The frequencyamplitude relation of nonlinear vibration is also investigated. Some conclusions can be obtain...
13 trang | Chia sẻ: huongthu9 | Ngày: 12/08/2021 | Lượt xem: 455 | Lượt tải: 0
A coupling successive approximation method for solving duffing equation and its application
Findings of the paper are summarized as follows: 1. An algorithm to solve the Duffing equation is proposed, in which a method to transform the initial equation to the resulting equation and a coupling successive approximation method (CSAM) to solve the resulting equation are presented. 2. Based on the proposed algorithm, the analytic approximate...
19 trang | Chia sẻ: huongthu9 | Ngày: 12/08/2021 | Lượt xem: 497 | Lượt tải: 0
Transient analysis of laminated composite plates using nurbs-Based isogeometric analysis
composite plates is first studied. The displacement field is generally defined and is derived from CPT. The Newmark time-integration algorithm was chosen to approximate the ordinary differential equations in time. We have successfully extended an application of the NURBS-based isogeometric finite element approach to analyze dynamic response for ...
17 trang | Chia sẻ: huongthu9 | Ngày: 12/08/2021 | Lượt xem: 419 | Lượt tải: 0
Calculation of transonic flows around profiles with blunt and angled leading edges
In fact, transonic flows are used for large civil aircraft and other flight objects. The implementation of computational methods and deep understandings of physical nature of the transonic flow are always needed [6, 7]. The above analysis for subsonic-transonic flow and supersonic-transonic flow allows drawing the following conclusions. It is c...
13 trang | Chia sẻ: huongthu9 | Ngày: 12/08/2021 | Lượt xem: 459 | Lượt tải: 0