An efficient thick beam theory and finite element model with zig-zag sublaminate approximations

Author(s):  
R Averill ◽  
Y Yip
2012 ◽  
Vol 04 (01) ◽  
pp. 1250010 ◽  
Author(s):  
V. P. VALLALA ◽  
G. S. PAYETTE ◽  
J. N. REDDY

In this paper, a finite element model for efficient nonlinear analysis of the mechanical response of viscoelastic beams is presented. The principle of virtual work is utilized in conjunction with the third-order beam theory to develop displacement-based, weak-form Galerkin finite element model for both quasi-static and fully-transient analysis. The displacement field is assumed such that the third-order beam theory admits C0 Lagrange interpolation of all dependent variables and the constitutive equation can be that of an isotropic material. Also, higher-order interpolation functions of spectral/hp type are employed to efficiently eliminate numerical locking. The mechanical properties are considered to be linear viscoelastic while the beam may undergo von Kármán nonlinear geometric deformations. The constitutive equations are modeled using Prony exponential series with general n-parameter Kelvin chain as its mechanical analogy for quasi-static cases and a simple two-element Maxwell model for dynamic cases. The fully discretized finite element equations are obtained by approximating the convolution integrals from the viscous part of the constitutive relations using a trapezoidal rule. A two-point recurrence scheme is developed that uses the approximation of relaxation moduli with Prony series. This necessitates the data storage for only the last time step and not for the entire deformation history.


1998 ◽  
Vol 531 ◽  
Author(s):  
J. M. Anderson ◽  
J. F. Malluck ◽  
M. M. Tabaddo ◽  
C. K. Sidbury ◽  
T. E. McNeil

AbstractMany of the broken fibers in optical connectors, especially those that seem to occur over time without apparent provocation are found in the ferrule at the transition from entry cone to alignment capillary. This paper contends that many such breaks are due to local stresses caused by debris or some other relatively rigid imperfection in the transition neighborhood. Stress estimates from beam theory and from a finite-element model are presented along with some indirect experimental observations supporting the contention.


Author(s):  
Matthew Daly ◽  
Armaghan Salehian ◽  
Alireza Doosthoseini

The following paper presents the results of a thermal robustness assessment of a rigidized space inflatable boom. Modal testing is performed at three different environmental temperatures; spanning a range of 38°C, with the purpose of characterizing dynamic behavior and assessing changes in bending frequencies. Experimental results show that the natural frequencies of the boom shift only marginally within the tested bandwidth. A finite element model is developed in parallel with experiments to determine compatibility with beam theory. The resulting simulation shows that linear beam theory can be used to predict bending frequencies and frequency response function magnitudes with very good accuracy.


2008 ◽  
Author(s):  
Mauro Luis Ramalho Sanches ◽  
Sérgio Frascino Müller de Almeida

2012 ◽  
Vol 522 ◽  
pp. 593-597
Author(s):  
Peng Li ◽  
Li Zhi Gu

With its technological development, the CNC embroidery machine rotational speed has increased dramatically. Consequent vibration and noise increase the disconnection rate in the embroidery process and affect the embroidery quality and production efficiency. To solve such problem, by analyzing the vibration causes and comparing the different characteristics of the Timoshenko beam and the Euler-Benouli simply supported beam, the current study indicated the limitation of the traditional vibration analysis method---the widely-used Euler-Bernouli simple beam theory, and constructed a vibration model based on the Timoshenko beam theory. Then a finite element model of the embroidery machine beam was built S and the corresponding experiment were done. Results from the constructed mechanical, mathematical model, and the ANSYS finite element model were compared. It has been verified that the constructed models are consistent with experiment results and that vibration models are constructed reasonably and feasibly. According to these models, the key parameters affecting the beam vibration are identified to work out more accurate and effective structure optimization design and prediction.


Structures ◽  
2020 ◽  
Vol 27 ◽  
pp. 2025-2033
Author(s):  
Md. Alhaz Uddin ◽  
Majed Abdulrahman Alzara ◽  
Noor Mohammad ◽  
Ahmed Yosri

Author(s):  
Sudip Ganguly

In order to evaluate the stiffness and perform detailed stress analysis of thick wall flange and flued expansion joint, a computer program based on finite element method was developed in C++, using 8-node axisymmetric element. Traditionally the analysis of expansion joints had been performed using the plate and beam theory which had several limitations and lead to inaccurate estimation of expansion joint stiffness and stresses. In this paper, initially the finite element mathematical model will be discussed, followed by comparison of the results of the stiffness calculations and stress analysis from the past method and that of the above-mentioned finite element model, and finally summarized by some discussions on the dependency of the accuracy of the results on the mesh density of the finite element model. The aforementioned finite element engine would be integrated to the pressure vessel and heat exchanger mechanical design software, AutoPIPE Vessel in the near future.


Author(s):  
Y. C. Fan ◽  
M. S. Ju ◽  
Y. G. Tsuei

The vibration of a rotating blade is investigated in this work. A rotor system is built and natural frequencies of the rotating blade are measured and compared with the numerical results from a finite element analysis. The experimental setup has a strain gage-based telemetry system and a piezoelectric shaker that rotates with the rotor. The finite element model of the beam is derived based on the Timoshenko beam theory. The effects of varying rotating speeds and stagger angles on the blade natural frequencies are studied. The results indicate that the natural frequencies calculated from the finite element model and the experimental values are in good agreement. It is found that the blade natural frequencies increase with the rotating speed in a nonlinear linear way. The effects of the stagger angle on the measured natural frequencies are not clear.


1994 ◽  
Vol 116 (3) ◽  
pp. 672-677 ◽  
Author(s):  
Y. C. Fan ◽  
M. S. Ju ◽  
Y. G. Tsuei

The vibration of a rotating blade is investigated in this work. A rotor system is built and natural frequencies of the rotating blade are measured and compared with the numerical results from a finite element analysis. The experimental setup has a strain-gage-based telemetry system and a piezoelectric shaker that rotates with the rotor. The finite element model of the beam is derived based on the Timoshenko beam theory. The effects of varying rotating speeds and stagger angles on the blade natural frequencies are studied. The results indicate that the natural frequencies calculated from the finite element model and the experimental values are in good agreement. It is found that the blade natural frequencies increase with the rotating speed in a nonlinear way. The effects of the stagger angle on the measured natural frequencies are not clear.


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