NON LINEAR DYNAMIC ANALYSIS OF THIN-WALLED STRUCTURES ADOPTING A MIXED BEAM FINITE ELEMENT MODEL WITH OUT-OF-PLANE CROSS-SECTION WARPING

2019 ◽  
Author(s):  
Paolo Di Re ◽  
Daniela Addessi ◽  
Achille Paolone
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Dynamic Analysis ◽  
Cross Section ◽  
Element Model ◽  
Linear Dynamic ◽  
Thin Walled Structures ◽  
Mixed Beam ◽  
Out Of Plane ◽  
Thin Walled

scholarly journals Dynamic Analysis of Tapered Thin-Walled Beams Using Spectral Finite Element Method

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Yiping Shen ◽  
Zhijun Zhu ◽  
Songlai Wang ◽  
Gang Wang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Wind Turbine ◽  
Element Model ◽  
Rotor Blades ◽  
Mode Shapes ◽  
Modal Frequency ◽  
Thin Walled Structures ◽  
Thin Walled ◽  
Spectral Finite Element

Tapered thin-walled structures have been widely used in wind turbine and rotor blade. In this paper, a spectral finite element model is developed to investigate tapered thin-walled beam structures, in which torsion related warping effect is included. First, a set of fully coupled governing equations are derived using Hamilton’s principle to account for axial, bending, and torsion motion. Then, the differential transform method (DTM) is applied to obtain the semianalytical solutions in order to formulate the spectral finite element. Finally, numerical simulations are conducted for tapered thin-walled wind turbine rotor blades and validated by the ANSYS. Modal frequency results agree well with the ANSYS predictions, in which approximate 30,000 shell elements were used. In the SFEM, one single spectral finite element is needed to perform such calculations because the interpolation functions are deduced from the exact semianalytical solutions. Coupled axial-bending-torsion mode shapes are obtained as well. In summary, the proposed spectral finite element model is able to accurately and efficiently to perform the modal analysis for tapered thin-walled rotor blades. These modal frequency and mode shape results are important to carry out design and performance evaluation of the tapered thin-walled structures.

Influence of the Subtended Angle on the Behavior of Folded Tape Springs

2018 ◽  
Author(s):  
Marinus G. de Jong ◽  
Werner W. P. J. van de Sande ◽  
Just L. Herder
Keyword(s):  
Finite Element ◽  
Cross Section ◽  
Strain Energy ◽  
Element Model ◽  
Constant Cross Section ◽  
Curvature Analysis ◽  
Thin Walled Structures ◽  
Constant Radius ◽  
Thin Walled ◽  
Force Generator

Tape springs are thin-walled structures with zero longitudinal and constant transverse curvature. Folding them twice and connecting both ends creates a tape loop which acts as a linear guide. When using a tape spring with a non-constant cross-section, a force generator can be created. At this time there is insufficient understanding of the influence of the tape spring’s cross-section on its behavior. This study investigates the influence of the subtended angle on the tape spring’s behavior, especially the energy distribution and the fold radius. A tape spring is once folded in a finite element model. By performing a curvature analysis of this folded geometry, the different regions within a tape spring are identified. This information is used to identify the amount of strain energy of each region. Finally, the fold radius and fold angle are determined by analyzing the geometry of the bent region. The analysis showed that the energy within the transition regions cannot be neglected. The energy within these regions as ratio of the total energy and the length of the transition regions both increase with the subtended angle. It is also shown that the fold radius is not constant when the subtended angle is small. Therefore, when designing a force generator using tape loops, the energy within the transition regions should be taken into account. The subtended angle should not be small to ensure a constant radius.

scholarly journals Finite element shear models of thin-walled structures of water management systems of agro-industrial complex

2020 ◽  
Vol 17 ◽  
pp. 00133
Author(s):  
Yuriy Klochkov ◽  
Tlek Ishchanov ◽  
Alexandr Andreev ◽  
Mikhail Klochkov
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Vector Fields ◽  
Rotation Angle ◽  
Displacement Vector ◽  
Element Model ◽  
Curvilinear Coordinates ◽  
Industrial Complex ◽  
Thin Walled Structures ◽  
Thin Walled

The article presents an algorithm for constructing a finite element model of deformation of thin-walled structures such as pipelines, tanks, bunkers included in the structure of the agro-industrial complex. The proposed model takes into account the deformation of the transverse shear. As a finite element, it is proposed to use a quadrangular fragment of the middle surface of a thin-walled structure of the agro-industrial complex with nodes located at its vertices. The components of the displacement vector and their partial derivatives of the first order with respect to curvilinear coordinates, as well as the components of the normal rotation angle vector, were chosen as the required unknowns. In the construction of the finite element model, the developed interpolation procedure was used for the components of the displacement vector and the component of the normal rotation angle vector as components of vector fields. The efficiency of the proposed finite element models in terms of a significant increase in the accuracy of calculations, the convergence of the computational process and the adequacy of the results to the physical meaning of the problem was proved on the numerical example of the calculation of the pipeline fragment.

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