scholarly journals Analytical model for flexural damping responses of CFRP cantilever beams in the low-frequency vibration

2018 ◽  
Vol 37 (4) ◽  
pp. 669-681 ◽  
Author(s):  
Mo Yang ◽  
Yefa Hu ◽  
Jinguang Zhang ◽  
Guoping Ding ◽  
Chunsheng Song
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Natural Frequency ◽  
Analytical Model ◽  
Flexural Vibration ◽  
Maximum Error ◽  
Damping Capacity ◽  
Element Analysis ◽  
First Order ◽  
Specific Damping Capacity

In this paper, an analytical model for the flexural vibration damping of Carbon Fiber Reinforced Plastics (CFRP) cantilever beams was proposed, which is based on the Lamination Theory and Euler–Bernoulli Beam Theory. By using a finite element analysis and an analytical model, four sets of specific damping capacity with different pavement schemes were predicted, and flexural vibration test and damping analysis were carried out. Comparing the analytical model, finite element analysis, and test results, it could be found that the analytical model had relatively good accuracy in predicting the first-order natural frequency and specific damping capacity of the bending vibration of CFRP beams. The maximum error of the first-order natural frequency between the analysis result and the experimental result was 7.05%; the maximum specific damping capacity error was only 5.65%. Comparing the finite element analysis method and the experiment results, the maximum error of the first-order natural frequency was 7.8%, the error of the specific damping capacity was bigger, and the [±30°]5S specimen was as high as 18.7%. However, there was a significant error when the analytical model was used to predict the second-order natural frequency and the specific damping capacity of CFRP beam’s flexural vibration.

scholarly journals Detection of Friction Stir Welding Defects of AA1060 Aluminum Alloy Using Specific Damping Capacity

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2437 ◽  
Author(s):  
Waheed AbuShanab ◽  
Essam Moustafa
Keyword(s):  
Finite Element ◽  
Friction Stir Welding ◽  
Natural Frequency ◽  
Dynamic Properties ◽  
Damping Ratio ◽  
Impact Testing ◽  
Damping Capacity ◽  
Element Analysis ◽  
Friction Stir ◽  
Specific Damping Capacity

The demand for nondestructive testing has increased, especially in welding testing. In the current study, AA1060 aluminum plates were jointed using the friction stir welding (FSW) process. The fabricated joints were subjected to free vibration impact testing in order to investigate the dynamic properties of the welded joint. Damping capacity and dynamic modulus were used in the new prediction method to detect FSW defects. The data acquired were processed and analyzed using a dynamic pulse analyzer lab shop and ME’Scope’s post-processing software, respectively. A finite element analysis using ANSYS software was conducted on different types of designed defects to predict the natural frequency. The results revealed that defective welded joints significantly affect the specific damping capacity. As the damping ratio increased, so did the indication of opportunities to increase the presence of defects. The finite element simulation model was consistent with experimental work. It was therefore revealed that natural frequency was insufficient to predict smaller defects.

scholarly journals Investigation of the Damping Capacity of CFRP Raft Frames

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 653
Author(s):  
Jinguang Zhang ◽  
Jun Rao ◽  
Lei Ma ◽  
Xianglong Wen
Keyword(s):  
Natural Frequency ◽  
Simulation Analysis ◽  
Plate Theory ◽  
Damping Ratio ◽  
Great Influence ◽  
Maximum Error ◽  
Bottom Plate ◽  
Damping Capacity ◽  
Element Analysis ◽  
First Order

In this paper, based on the composite laminated plate theory and a strain energy model, the damping capacity of a Carbon Fiber Reinforced Plastics (CFRP) raft frame was studied. According to the finite element analysis (FEA) and damping ratio prediction model, the influences of different layups on the damping capacity of the raft frame and its components (top/bottom plate and I-support) were discussed. Comparing the FEA results with the test results, it can be figured out that the CFRP laminate layup has a great influence on the damping ratio of the raft frame, and the maximum error of the first-order natural frequency and damping ratio of the top/bottom plate were 5.6% and 15.1%, respectively. The maximum error of the first-order natural frequency of the I-support between the FEA result and the test result was 7.5%, suggesting that because of the stress concentration, the error of the damping ratio was relatively large. As for the raft frame, the damping performance was affected by the I-support arrangement and the simulation analysis was in good agreement with the experimental results. This study can provide a useful reference for improving the damping performance of CFRP raft frames.

Investigation of stiffness of small wind turbine blade based on vibration analysis technique

2019 ◽  
Vol 44 (1) ◽  
pp. 49-59
Author(s):  
Nilesh Chandgude ◽  
Nitin Gadhave ◽  
Ganesh Taware ◽  
Nitin Patil
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Wind Turbine ◽  
Natural Frequency ◽  
Vibration Analysis ◽  
Natural Frequencies ◽  
Mode Shapes ◽  
Element Analysis ◽  
Finite Element Software ◽  
Small Wind Turbine

In this article, three small wind turbine blades of different materials were manufactured. Finite element analysis was carried out using finite element software ANSYS 14.5 on modeled blades of National Advisory Committee for Aeronautics 4412 airfoil profile. From finite element analysis, first, two flap-wise natural frequencies and mode shapes of three different blades are obtained. Experimental vibration analysis of manufactured blades was carried out using fast Fourier transform analyzer to find the first two flap-wise natural frequencies. Finally, the results obtained from the finite element analysis and experimental test of three blades are compared. Based on vibration analysis, we found that the natural frequency of glass fiber reinforced plastic blade reinforced with aluminum sheet metal (small) strips increases compared with the remaining blades. An increase in the natural frequency indicates an increase in the stiffness of blade.

Numerical Evaluation of the Active Earth Pressure Acting on Rigid Retaining Walls

2012 ◽  
Vol 204-208 ◽  
pp. 410-413
Author(s):  
Shi Lun Feng ◽  
Jun Li ◽  
Pu Lin Li
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Retaining Wall ◽  
Earth Pressure ◽  
Maximum Error ◽  
Active Earth Pressure ◽  
Element Analysis ◽  
Finite Element Software ◽  
Strain Behaviour ◽  
The Finite Element Analysis

The active earth pressure on rigid retaining wall is analyzed using the finite element software ABAQUS. The fill behind the wall is sand and the Mohr–Coulomb constitutive model was used to model the stress–strain behaviour of soils.The finite element analysis results were compared with the Rankine results. The maximum error of the results is about 10% and the finite element analysis result is bigger. So the result obtained from the finite element method could safely be used in actual projects.

Simulations and Experiment Analysis of a Piezoelectric Micropump

2012 ◽  
Vol 229-231 ◽  
pp. 1688-1692 ◽  
Author(s):  
Yan Fang Guan ◽  
Ming Gang Shen ◽  
Li Li Han
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Flow Rate ◽  
Piezoelectric Transducer ◽  
Working Condition ◽  
Coupling Analysis ◽  
Element Analysis ◽  
Deep Reactive Ion Etching ◽  
First Order ◽  
Experiment Analysis

The application of micropump in microanalytical reagent is widely. In this paper a piezoelectric micropump model that looks like a sandwitch has been put forward. The main structures of the micropump include inlet and outlet pipe, silicon substrate pump body, piezoelectric transducer. In order to find the excellent driving performance, the modals and piezoelectric-stress coupling analysis of the piezoelectric transducer has been carried out with finite element analysis methods. The result proves that the optimal working condition of the micropump is the 1st mode. Finally the micropump model has been fabricated with silicon deep reactive ion etching and UV irreversible irradiation. Through experiment the flow rate and pressure of the micropump reach the maximum in first-order modal that is less than 1000 Hz, and this is accord with the modal analysis.

Collapse characteristics of a circular-cross-section CFRP pipe structure member using finite element analysis

e-Polymers ◽  
2018 ◽  
Vol 18 (1) ◽  
pp. 27-33
Author(s):  
Dae Young Kim ◽  
Hee Seong Kim ◽  
Ji Hoon Kim
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Composite Materials ◽  
Carbon Fibers ◽  
Error Rate ◽  
Material Properties ◽  
Structural Characteristics ◽  
Circular Cross Section ◽  
Maximum Error ◽  
Element Analysis

AbstractCarbon fiber reinforced plastics (CFRPs) are advanced composite materials that have been used as lightweight structural materials for vehicles. Unlike general isotropic materials, the structural characteristics of composite materials are strongly influenced by the stacking directions and sequences of the composite laminates. In this study, finite element analysis was used to predict the material properties of the carbon fibers and the resin composing a CFRP in cases of laminated carbon fibers and modified external angles. The results verify the approach’s reliability by comparing the simulation results and the real test results related to the material properties of the carbon fibers and the resin. The results of the finite element analysis and the experimental results were compared with the load-displacement curves and the maximum load. The [02/902]S, [902/02]2, and [0/90]2S specimens showed a maximum error rate of 8.6%, whereas the [902/02]S, [02/902]2, and [90/0]2S specimens showed a maximum error rate of approximately 12.93%. By applying CFRP static collapse analysis of fiber properties and resin properties through basic experiments and basic theory, we predicted the properties of CFRPs through finite element analysis; an error rate of approximately 10% indicated that our approach is effective.

Development of Hybrid Semi-Analytical and Finite Element Analysis to Calculate Sound Radiation from Vibrating Structure

2013 ◽  
Vol 845 ◽  
pp. 71-75 ◽  
Author(s):  
Azma Putra ◽  
Nurain Shyafina ◽  
Noryani Muhammad ◽  
Hairul Bakri ◽  
Noor Fariza Saari
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Boundary Conditions ◽  
Rectangular Plate ◽  
Analytical Model ◽  
Complex Geometry ◽  
Sound Radiation ◽  
Vibration Velocity ◽  
Rectangular Plates ◽  
Element Analysis

Simple analytical model of plate dynamics usually applies for rectangular plate with simply supported edges. Analytical model of sound radiation from rectangular plate is also convenient, but not for other geometries and other boundary conditions. This paper presents a hybrid mathematical model which combines a semi-analytical model with the Finite Element Analysis (FEA) method to determine sound radiation from a vibrating structure. The latter is employed to calculate the vibration velocity of a structure with a rather complex geometry. The results are then used as the input in the semi-analytical model to calculate the radiated sound pressure through the Rayleigh integral. Results from the proposed model are presented here for the radiation efficiency of rectangular plates with different boundary conditions.

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