Vibration Characteristics Analysis of an Elastic Cavity

2015 ◽  
Vol 775 ◽  
pp. 9-13
Author(s):  
Man Kang ◽  
Jing Lu
Keyword(s):  
Structural Design ◽  
Present Method ◽  
Integration Method ◽  
Vibration Characteristics ◽  
The Finite Element Method ◽  
Equilibrium Equations ◽  
Precise Integration ◽  
Design And Optimization ◽  
Characteristics Analysis ◽  
Relationship Of

A semi-analytical method was proposed to analyze the vibration characteristics of an elastic cavity. Combining the precise integration method and bent theory of the beam, the transfer relationship of the ends of the beam was derived. Based on the displacement continuity conditions and equilibrium equations of the junction, the conversion relation of the beams was also established. Then, the dynamics control equations of an elastic cavity were assembled by the above relationship and boundary conditions. The comparison with the FEM had verified the accuracy of the present method. This method avoids the shortage that the calculation accuracy over-depends on the element types and the mesh dividing methods, which is existed in the finite element method. In addition to this, the process of this method is efficient, so it is a useful method to the structural design and optimization of the cavity.

The Vibration Characteristics Analysis of Ship Foundation Based on the Arrangement of Isolators

2011 ◽  
Vol 55-57 ◽  
pp. 2202-2205
Author(s):  
Yu Wang ◽  
Xing Lin Chen ◽  
Guang Min Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Natural Frequency ◽  
Vibration Characteristics ◽  
Force Characteristic ◽  
The Finite Element Method ◽  
Foundation Vibration ◽  
Characteristics Analysis ◽  
Excitation Force ◽  
General Connection

Contrary to the general connection style, the vibration characteristics of the ship foundation vibration is researched under the arrangement style of isolators acted on it. And the influence of the parameters of rigidity and damp to the excitation force characteristic is studied too. Based on the real ship data and the finite element method, the study is shown that the excitation force from the device to the foundation is not only related to the rigidity, damp of isolators and the natural frequency of device-isolator-foundation system but also the related to arrangement style of isolator. When the excited frequency is lower it had little effect on the vibration characteristics relatively. However that the frequency is higher, it had significant effect on the vibration.

Vibration characteristics analysis of disordered two-span beams with numerical and experimental methods

2017 ◽  
Vol 24 (16) ◽  
pp. 3641-3657 ◽  
Author(s):  
Shenglin Zhou ◽  
Fengming Li ◽  
Chuanzeng Zhang
Keyword(s):  
Time History ◽  
Frequency Equation ◽  
Vibration Characteristics ◽  
Experimental Investigations ◽  
Superposition Method ◽  
The Finite Element Method ◽  
Response Curves ◽  
Modal Superposition Method ◽  
Characteristics Analysis ◽  
Good Agreement

Numerical and experimental investigations on the vibration behaviors of the disordered two-span beams have been conducted. The dynamics model of the two-span beam is established and solved by means of the modal superposition method. According to the boundary conditions, the frequency equation of the two-span beam is obtained, and the natural frequencies, vibration modes, frequency response curves, and time-history responses of the structure are also obtained consequently. Considering the structural size disorder due to the two different sub-span lengths of the two-span beam, a disorder ratio is introduced in terms of the two sub-span lengths and its influences on the vibration characteristics of the structure are analyzed. By comparing the results from numerical calculation with those from the finite element method (FEM) and experiments, good agreement is observed, which verifies the validity of the present investigations.

scholarly journals The free vibration characteristics of isotropic coupled conical-cylindrical shells based on the precise integration transfer matrix method

2017 ◽  
Vol 4 (1) ◽  
pp. 272-287
Author(s):  
Fuzhen Pang ◽  
Chuang Wu ◽  
Hongbao Song ◽  
Haichao Li
Keyword(s):  
Free Vibration ◽  
Boundary Conditions ◽  
Transfer Matrix ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Shell Thickness ◽  
Natural Frequencies ◽  
Integration Method ◽  
Vibration Characteristics ◽  
Precise Integration

Abstract Based on the transfer matrix theory and precise integration method, the precise integration transfer matrix method (PITMM) is implemented to investigate the free vibration characteristics of isotropic coupled conicalcylindrical shells. The influence on the boundary conditions, the shell thickness and the semi-vertex conical angle on the vibration characteristics are discussed. Based on the Flügge thin shell theory and the transfer matrix method, the field transfer matrix of cylindrical and conical shells is obtained. Taking continuity conditions at the junction of the coupled conical-cylindrical shell into consideration, the field transfer matrix of the coupled shell is constructed. According to the boundary conditions at the ends of the coupled shell, the natural frequencies of the coupled shell are solved by the precise integration method. An approach for studying the free vibration characteristics of isotropic coupled conical-cylindrical shells is obtained. Comparison of the natural frequencies obtained using the present method with those from literature confirms the validity of the proposed approach. The effects of the boundary conditions, the shell thickness and the semivertex conical angle on vibration characteristics are presented.

Analysis on Vibration Characteristics of PSM Induction Synchronization Segment Based on Finite Element

2014 ◽  
Vol 556-562 ◽  
pp. 763-766
Author(s):  
Wei Chen ◽  
Qing Xuan Jia ◽  
Han Xu Sun ◽  
Si Cheng Nian
Keyword(s):  
Finite Element ◽  
Natural Frequency ◽  
Structural Design ◽  
Simulation Analysis ◽  
Vibration Characteristics ◽  
The Finite Element Method ◽  
Sorting Machine ◽  
Vibration Model ◽  
The Relationship ◽  
Operation Frequency

The vibration of the induction synchronization segment (ISS) have an important influence on the parcel loading accuracy and the service life of the parcel sorting machine (PSM). The vibration model of the ISS is established by using the finite element method. And the analysis of the structural design impact on the natural frequency of the ISS is provided. The relationship between the operation frequency and the natural frequency of the ISS is obtained by means of the modal simulation analysis. The vibration characteristics of the ISS can provide reference frame for the design.

scholarly journals Research on the Manufacturing Quality of Co-Cured Hat-Stiffened Composite Structure

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2747
Author(s):  
Xiangwen Ju ◽  
Jun Xiao ◽  
Dongli Wang ◽  
Cong Zhao ◽  
Xianfeng Wang
Keyword(s):  
Composite Structures ◽  
Sound Pressure ◽  
Integration Method ◽  
Complex Geometry ◽  
Sound Field ◽  
Thickness Measurement ◽  
Curing Process ◽  
The Finite Element Method ◽  
Manufacturing Quality

The stringer-stiffened structure is widely used due to its excellent mechanical properties. Improving the manufacturing quality of stringer-stiffened structure which have complex geometry is important to ensure the bearing capacity of aviation components. Herein, composite hat-stiffened composite structures were manufactured by different filling forms and bladders with various properties, the deformation of silicone rubber bladder in co-curing process was studied by using the finite element method. The thickness measurement at different positions of the hat-stiffened structure was performed to determine the best filling form and bladder property. Moreover, in view of the detection difficulties in R-zone of stringer, numerical simulation was performed to get the sound pressure and impulse response of at the R-zone of stringer by Rayleigh integration method, and an effective equipment which could stably detect the manufacturing quality of R-zone was designed to verify the correctness of sound field simulation and realize the detection of stringer. With the optimum filling form and bladder properties, hat-stiffened composites can be manufactured integrally with improved surface quality and geometric accuracy, based on co-curing process.

Semi-inverse method for predicting stress–strain relationship from cone indentations

2003 ◽  
Vol 18 (9) ◽  
pp. 2068-2078 ◽  
Author(s):  
A. DiCarlo ◽  
H. T. Y. Yang ◽  
S. Chandrasekar
Keyword(s):  
A Priori ◽  
Model Material ◽  
Material Behavior ◽  
The Finite Element Method ◽  
Stress Strain ◽  
Indentation Tests ◽  
Strain Relationship ◽  
Initial Force ◽  
Relationship Of ◽  
Force Displacement

A method for determining the stress–strain relationship of a material from hardness values H obtained from cone indentation tests with various apical angles is presented. The materials studied were assumed to exhibit power-law hardening. As a result, the properties of importance are the Young's modulus E, yield strength Y, and the work-hardening exponent n. Previous work [W.C. Oliver and G.M. Pharr, J. Mater. Res. 7, 1564 (1992)] showed that E can be determined from initial force–displacement data collected while unloading the indenter from the material. Consequently, the properties that need to be determined are Y and n. Dimensional analysis was used to generalize H/E so that it was a function of Y/E and n [Y-T. Cheng and C-M. Cheng, J. Appl. Phys. 84, 1284 (1999); Philos. Mag. Lett. 77, 39 (1998)]. A parametric study of Y/E and n was conducted using the finite element method to model material behavior. Regression analysis was used to correlate the H/E findings from the simulations to Y/E and n. With the a priori knowledge of E, this correlation was used to estimate Y and n.

scholarly journals Precise Integration Method for Solving Noncooperative LQ Differential Game

2013 ◽  
Vol 2013 ◽  
pp. 1-9
Author(s):  
Hai-Jun Peng ◽  
Sheng Zhang ◽  
Zhi-Gang Wu ◽  
Biao-Song Chen
Keyword(s):  
Differential Equation ◽  
Differential Game ◽  
Integration Method ◽  
Transformation Method ◽  
Linear Quadratic ◽  
Riccati Differential Equation ◽  
Precise Integration ◽  
Precise Integration Method ◽  
Direct Integration Method ◽  
Two Parameters

The key of solving the noncooperative linear quadratic (LQ) differential game is to solve the coupled matrix Riccati differential equation. The precise integration method based on the adaptive choosing of the two parameters is expanded from the traditional symmetric Riccati differential equation to the coupled asymmetric Riccati differential equation in this paper. The proposed expanded precise integration method can overcome the difficulty of the singularity point and the ill-conditioned matrix in the solving of coupled asymmetric Riccati differential equation. The numerical examples show that the expanded precise integration method gives more stable and accurate numerical results than the “direct integration method” and the “linear transformation method”.

Affected Characteristics Analysis of the Pulsed Laser Forming of Metal Sheet

2008 ◽  
Vol 375-376 ◽  
pp. 333-337
Author(s):  
Li Jun Yang ◽  
Yang Wang
Keyword(s):  
Laser Beam ◽  
Pulsed Laser ◽  
Metal Sheet ◽  
Grain Structure ◽  
Experimental Result ◽  
Laser Forming ◽  
Forming Process ◽  
Grain Orientations ◽  
Characteristics Analysis ◽  
Relationship Of

Laser forming of metal sheet is a forming technology of sheet without a die that the sheet is deformed by internal thermal stress induced by partially irradiation of a laser beam. In this paper, the bending behavior of common stainless steel 1Cr18Ni9 sheet is studied after being irradiated by straight line with a Nd:YAG pulsed laser beam. The aim of the investigation is to find out the relationship of the physical behaviors of heat affected zone (HAZ) with the pulse parameters of the laser. Through the analysis of the fundamental theory of pulsed laser affected, this paper shows the affected characteristics of metal sheet with pulsed laser forming. The results show that the microstructure of HAZ of pulsed laser scanned is layered, and the micro-hardness is improved than that in matrix. The microstructures show that the deformed grain structure is inhomogeneous, that caused the grain sizes and grain orientations in HAZ to become different. By qualitative analysis of experimental result, the conclusion obtained may provide basis for theoretical investigation and possible industrial application of laser forming process in the future.

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