An Investigation of Power Flow in the Mid-Frequency Range for Systems of Co-Linear Beams Based on a Hybrid Finite Element Formulation

2000 ◽  
Author(s):  
Xi Zhao ◽  
Nickolas Vlahopoulos
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Power Flow ◽  
Radiation Effects ◽  
Flow Characteristics ◽  
Element Formulation ◽  
Damping Properties ◽  
Frequency Range ◽  
Element Analysis ◽  
Hybrid Finite Element

Abstract A hybrid finite element analysis (hybrid FEA) is employed for investigating power flow characteristics for systems of co-linear beams in the mid-frequency range. The importance of capturing power re-injection and power re-radiation effects in the solution is demonstrated. The dependency of the power flow characteristics of a system in the mid-frequency range on the rigidity, mass, and damping properties of its components is determined. Both the hybrid FEA and analytical solutions are employed for analyses in order to establish the viability of the hybrid FEA as a simulation technology in the mid-frequency range.

A Hybrid Finite Element Method for Calculating the Vibration of Co-Linear Beams in the Mid-Frequency Range

1999 ◽  
Author(s):  
Xi Zhao ◽  
Nickolas Vlahopoulos
Keyword(s):  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Theoretical Development ◽  
Frequency Range ◽  
Element Analysis ◽  
Hybrid Finite Element Method ◽  
Hybrid Finite Element ◽  
New Formulation ◽  
Element Method

Abstract The theoretical development of a hybrid finite element method is presented. It combines conventional Finite Element Analysis (FEA) with Energy Finite Element Analysis (EFEA) in order to achieve a numerical solution to mid-frequency vibrations. In the mid-frequency range a system is comprised by some members that contain several wavelengths and some members that contain a small number of wavelengths. The former are considered long members and they are modeled by the EFEA. The latter are considered short and they are modeled by the FEA. The new formulation is based on deriving appropriate interface conditions at the joints between sections modeled by the EFEA and the FEA methods. Since the work presented in this paper constitutes a fundamental step in the development of a hybrid method for mid-frequency analysis, the formulation for one flexural degree of freedom in co-linear beams is presented. The excitation is considered to be applied on a long member and the response of the entire system is computed. Uncertainty effects are imposed only on the long members of the system. Validation cases for several configurations are presented.

A Hybrid Finite Element Formulation for Mid-Frequency Analysis of Systems With Excitation Applied on Short Members

2000 ◽  
Author(s):  
Xi Zhao ◽  
Nickolas Vlahopoulos
Keyword(s):  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Input Power ◽  
Element Formulation ◽  
Element Analysis ◽  
Theoretical Formulation ◽  
Hybrid Finite Element Method ◽  
Hybrid Finite Element ◽  
Element Method

Abstract A hybrid finite element method for computing mid-frequency vibrations is presented. In the mid-frequency region a system is comprised by some members that contain several wavelengths and some members that contain a small number of wavelengths within their dimensions. The former are considered long members and they are modeled by the Energy Finite Element Analysis (EFEA). The latter are considered short and they are modeled by the Finite Element Analysis (FEA). In this paper the excitation is considered to be applied on the short members. The hybrid formulation computes the response of the entire system. The characteristics of the long members affect the behavior of the short members and the amount of power flow between the members of the system. The resonant characteristics of the short members and the boundary conditions imposed by the long members determine the amount of input power into the system. The interaction between members is described by a set of equations between the FEA and the EFEA primary variables at the interfaces between long and short members. The equations for the short and the long members and the interface equations are solved simultaneously. A theoretical formulation and a numerical implementation for systems that contain one wave type is presented. Analytical solutions for several co-linear beam configurations are compared to numerical results produced by the hybrid finite element method. Good correlation is observed for all analyses.

Bond Thickness Effects upon Dynamic Behaviour in Adhesive Joints

2010 ◽  
Vol 97-101 ◽  
pp. 3920-3923 ◽  
Author(s):  
Xiao Cong He
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Dynamic Behaviour ◽  
Adhesive Layer ◽  
Adhesive Joints ◽  
Response Functions ◽  
Frequency Range ◽  
Element Analysis ◽  
Cantilevered Beam ◽  
Different Thickness

The influence of adhesive layer thickness on the dynamic behaviour of the single-lap adhesive joints is investigated in this paper. The ABAQUS finite element analysis (FEA) software was used to predict the frequency response functions (FRFs) of the single-lap adhesive joints of different thickness of the adhesive layer. As a reference, the FRFs of a cantilevered beam without joint were investigated as well. It is clear that the FRFs of the four beams are close to each other within the frequency range 0~1000 Hz. It is also found that the composite damping of the single-lap adhesive joint increases as the thickness of the adhesive layer increases.

Fabrication and finite element analysis of vibrating parallel film actuator made with cellulose acetate for potential haptic application

2016 ◽  
Vol 230 (15) ◽  
pp. 2720-2727 ◽  
Author(s):  
Md Mohiuddin ◽  
Asma Akther ◽  
Eun Byul Jo ◽  
Hyun Chan Kim ◽  
Jaehwan Kim
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cellulose Acetate ◽  
Vibration Characteristics ◽  
Experimental Results ◽  
Vibration Velocity ◽  
Frequency Range ◽  
Actuation Frequency ◽  
Element Analysis ◽  
Wide Range

The present study investigates a film actuator made with dielectric cellulose acetate films separated by narrow spacers as a means of electrostatic actuation for potential haptic application. Fabrication process for the actuator is explained along with experiments conducted over a wide frequency range of actuation frequency. A valid finite element simulation of the actuator is made on the quarter section of the actuator by using full 3D finite elements. Vibration characteristics such as fundamental natural frequency, mode shape and output velocity in the frequency range for haptic feeling generation are obtained from the finite element analysis and compared with the experimental results. Experimental results demonstrate that the finite element model is practical and effective enough in predicting the vibration characteristics of the actuator for haptic application. The film actuator shows many promising properties like high transparency, wide range of actuation frequency and high vibration velocity for instance.

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