Free vibration of thin-walled composite beams with I-shaped cross-sections

2002 ◽  
Vol 55 (2) ◽  
pp. 205-215 ◽  
Author(s):  
Jaehong Lee ◽  
Seung-Eock Kim
Keyword(s):  
Free Vibration ◽  
Cross Sections ◽  
Composite Beams ◽  
Thin Walled

Modal Analysis of Thin Walled Multi-Cell Multi-Tapered Composite Beams of Closed Cross Sections

2014 ◽  
Vol 629 ◽  
pp. 82-88 ◽  
Author(s):  
Sohail Ahmed ◽  
M.N. Ahmed
Keyword(s):  
Modal Analysis ◽  
Cross Sections ◽  
Natural Frequencies ◽  
Aerospace Industry ◽  
Composite Beams ◽  
Wind Gust ◽  
Aircraft Wing ◽  
Model Accuracy ◽  
Finite Element Package ◽  
Thin Walled

This paper explicitly highlights the modal analysis of thin walled multi-cell multi-tapered composite beams in cantilever configurations, using MSC Patran / Nastran finite element package. Initially, the verification of the model was done with the analytical results in order to ensure the model accuracy. All the multi-tapered beams under examination are composed of closed section and three cell configuration. There is a vivid description of all the effects of composite material and stacking sequence on the modal frequencies. It also suggests the ways to shift the natural frequencies of the multi-tapered beams. This paper verifies the effects of different geometrical configurations of beams (tapered angles, lengths and point of variation of tapered angles) on the modal frequencies. This research is also useful in aerospace industry while designing the aircraft wing, which would experience the vibrations due to wind gust and engine cycles.

Free vibration and dynamic stability of rotating thin-walled composite beams

2011 ◽  
Vol 30 (3) ◽  
pp. 432-441 ◽  
Author(s):  
C. Martín Saravia ◽  
Sebastián P. Machado ◽  
Víctor H. Cortínez
Keyword(s):  
Free Vibration ◽  
Dynamic Stability ◽  
Composite Beams ◽  
Thin Walled

Geometrically Nonlinear Vibration Analysis of Thin-Walled Composite Beams

2013 ◽  
Author(s):  
Seher Durmaz ◽  
Metin O. Kaya
Keyword(s):  
Linear Model ◽  
Cross Sections ◽  
Transverse Shear ◽  
Composite Beams ◽  
Beam Model ◽  
Geometrically Nonlinear ◽  
Sweep Angle ◽  
Wide Range ◽  
Thin Walled ◽  
Displacement Based

In this study, accounting for large displacements a geometrically nonlinear theory, which is valid for laminated thin-walled composite beams of open and closed cross sections, is developed. The beam model incorporates a number of non-classical effects such as material anisotropy, transverse shear deformation and warping restraint. Moreover, the directionality property of thin-walled composite beams produces a wide range of elastic couplings. In this respect, symmetric lay-up configuration i.e. Circumferentially Asymmetric Stiffness (CAS) is adapted to this model to generate coupled motion of flapwise bending-torsion-flapwise transverse shear. Initially, free vibration analyses are carried out for the linear model of the shearable and the non-shearable thin-walled composite beams. Similar to the linear model, the displacement-based nonlinear equations are derived by the variational formulation, considering the geometric non-linearity in the von Karman sense. Finally, the static and the dynamic analyses for the nonlinear beam model are carried out addressing the effects of transverse shear, fiber-orientation and sweep angle on the nonlinear frequencies and the static response of the beam.

Nonclassical Behavior of Thin‐Walled Composite Beams with Closed Cross Sections

1990 ◽  
Vol 35 (2) ◽  
pp. 42-50 ◽  
Author(s):  
Lawrence W. Rehfield ◽  
Ali R. Atilgan ◽  
Dewey H. Hodges
Keyword(s):  
Cross Sections ◽  
Transverse Shear ◽  
Composite Beams ◽  
Cross Sectional ◽  
Elastic Bending ◽  
Composite Blade ◽  
Beam Displacement ◽  
Thin Walled ◽  
Cantilevered Beams ◽  
Shear Coupling

This paper focuses on two nonclassical effects in the behavior of thin‐walled composite beams: elastic bending‐shear coupling and restrained torsional warping. These nonclassical effects are clarified and analyzed in some simple examples involving cantilevered beams. First, elastic bending‐transverse shear coupling is shown to be important in the analysis of beams designed for extension‐twist coupling. It is found that the lateral deflections ran be off by more than a factor of two if this coupling is ignored. This coupling stems from plies with off‐axis fibers in the beam. The presence of these plies affects significantly the modeling approach (i.e., determination of the constitutive equations) in that transverse shear must appear in the kinematics so that its coupling with bending will he exhibited in the elastic constants. This finding is in accord with “exact” beam theories which develop the beam displacement and cross sectional orientation in terms of six kinematical variables instead of the three or four found in some previously published works on composite blade modeling. A second nonclassical effect, torsional warping rigidity, is shown to be important far certain box beams having a thin‐walled, closed cross section. The importance of including these nonclassical phenomena in a complete theory is discussed in light of the magnitude of their effects for various values of configuration parameters.

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