scholarly journals Numerical/Experimental Validation of Thin-Walled Composite Box Beam Optimal Design

Aerospace ◽  
2020 ◽  
Vol 7 (8) ◽  
pp. 111
Author(s):  
Enrico Cestino ◽  
Giacomo Frulla ◽  
Paolo Piana ◽  
Renzo Duella
Keyword(s):  
Optimal Design ◽  
Composite Structures ◽  
Experimental Validation ◽  
Torsional Stiffness ◽  
Beam Model ◽  
Angle Distribution ◽  
Structural Configuration ◽  
Box Beam ◽  
Thin Walled ◽  
Composite Box Beam

Thin-walled composite box beam structural configuration is representative of a specific high aspect ratio wing structure. The optimal design procedure and lay-up definition including appropriate coupling necessary for aerospace applications has been identified by means of “ad hoc” analytical formulation and by application of commercial code. The overall equivalent bending, torsional and coupled stiffness are derived and the accuracy of the simplified beam model is demonstrated by the application of Altair Optistruct. A simple case of a coupled cantilevered beam with load at one end is introduced to demonstrate that stiffness and torsion angle distribution does not always correspond to the trends that one would intuitively expect. The maximum of torsional stiffness is not obtained with fibers arranged at 45° and, at the maximum torsional stiffness, there is no minimum rotation angle. This observation becomes essential in any design process of composite structures where the constraints impose structural couplings. Furthermore, the presented theory is also extended to cases in which it is necessary to include composite/stiffened hybrid configurations. Good agreement has been found between the theoretical simplified beam model and numerical analysis. Finally, the selected composite configuration was compared to an experimental test case. The numerical and experimental validation is presented and discussed. A good correlation was found confirming the validity of the overall optimization for the optimal lay-up selection and structural configuration.

A super-convergent thin-walled 3D beam element for analysis of laminated composite structures with arbitrary cross-section

2021 ◽  
pp. 1-23
Author(s):  
M. Talele ◽  
M. van Tooren ◽  
A. Elham
Keyword(s):  
Cross Sections ◽  
Composite Structures ◽  
Three Dimensional ◽  
Laminated Composite ◽  
Beam Element ◽  
Arbitrary Cross Section ◽  
Beam Model ◽  
Cross Sectional ◽  
Thin Walled ◽  
The Cross

Abstract An efficient, fully coupled beam model is developed to analyse laminated composite thin-walled structures with arbitrary cross-sections. The Euler–Lagrangian equations are derived from the kinematic relationships for a One-Dimensional (1D) beam representing Three-Dimensional (3D) deformations that take into account the cross-sectional stiffness of the composite structure. The formulation of the cross-sectional stiffness includes all the deformation effects and related elastic couplings. To circumvent the problem of shear locking, exact solutions to the approximating Partial Differential Equations (PDEs) are obtained symbolically instead of by numerical integration. The developed locking-free composite beam element results in an exact stiffness matrix and has super-convergent characteristics. The beam model is tested for different types of layup, and the results are validated by comparison with experimental results from literature.

MDO/MSO of Slender Thin Walled Box Beam Model

2017 ◽  
Author(s):  
Francesco Danzi ◽  
Giacomo Frulla ◽  
Enrico Cestino ◽  
James M. Gibert
Keyword(s):  
Beam Model ◽  
Box Beam ◽  
Thin Walled

Dynamic Instability of Cantilever Beams With Open Cross-Section

2016 ◽  
Author(s):  
Júlio C. Coaquira ◽  
Paulo B. Gonçalves ◽  
Eulher C. Carvalho
Keyword(s):  
Composite Structures ◽  
Dynamic Instability ◽  
Nonlinear Oscillations ◽  
Equations Of Motion ◽  
Beam Theory ◽  
Torsional Stiffness ◽  
Phase Portraits ◽  
Large Displacements ◽  
Torsional Coupling ◽  
Thin Walled

Structural elements with thin-walled open cross-sections are common in metal and composite structures. These thin-walled beams have generally a good flexural strength with respect to the axis of greatest inertia, but a low flexural stiffness in relation to the second principal axis and a low torsional stiffness. These elements generally have an instability, which leads to a flexural-flexural-torsional coupling. The same applies to the vibration modes. Many of these structures work in a nonlinear regime, and a nonlinear formulation that takes into account large displacements and the flexural-flexural-torsional coupling is required. In this work a nonlinear beam theory that takes into account large displacements, warping and shortening effects, as well as flexural-flexural-torsional coupling is adopted. The governing nonlinear equations of motion are discretized in space using the Galerkin method and the discretized equations of motion are solved by the Runge-Kutta method. Special attention is given to the nonlinear oscillations of beams with low torsional stiffness and its influence on the bifurcations and instabilities of the structure, a problem not tackled in the previous literature on this subject. Time responses, phase portraits and bifurcation diagrams are used to unveil the complex dynamic.

Coupled Mechanism on Interfacial Slip and Shear Lag for Twin-Cell Composite Box Beam Under Even Load

2017 ◽  
Vol 34 (5) ◽  
pp. 601-616 ◽  
Author(s):  
J. Yu ◽  
S. W. Hu ◽  
Y. C. Xu ◽  
B. Fan
Keyword(s):  
Composite Structures ◽  
Structural Features ◽  
Interfacial Slip ◽  
Shear Lag ◽  
Shear Lag Effect ◽  
Closed Form Solutions ◽  
Concrete Plate ◽  
Box Beam ◽  
Lag Effect ◽  
Composite Box Beam

AbstractA model of Twin-cell Composite Box Beam (TCCBB), which is composed of concrete plate and thin-walled steel box beam with twin-cell, is proposed in this paper. Combined with structural features, longitudinal interfacial slip mode (LISM) and related shear hysteresis functions (SHFS) of this TCCBB model are defined respectively; analytical formulation describing combination effect between interfacial slip and shear lag is launched for this TCCBB model under even load. Based on established governing differential equations and its relative boundary conditions (calculated with compatible mechanism of interfacial slip and shear lag effect), closed form solutions of normal stress and shear stress are derived for this TCCBB model, as well as effective shear-lag coefficient and effective coupled behavior coefficient. To obtain more accurate computational results of specific coupled mechanism of this TCCBB model, numerical example is carried out to analyze and predict coupled mechanism of interfacial slip and shear lag effect for this type of composite structures.

Analysis of thin-walled composite box beam under torsional load without external restraint

2002 ◽  
Vol 40 (4) ◽  
pp. 385-397 ◽  
Author(s):  
Yaping Wu ◽  
Yuanlin Zhu ◽  
Yuanming Lai ◽  
Xuefu Zhang ◽  
Shizhong Liu
Keyword(s):  
Torsional Load ◽  
Box Beam ◽  
Thin Walled ◽  
Composite Box Beam

Research on Ultimate Strength and Accumulated Plastic Deflection of Box Beam under Cyclic Loading

2014 ◽  
Vol 496-500 ◽  
pp. 567-570
Author(s):  
Hu Wei Cui ◽  
Ping Yang ◽  
Can Sen ◽  
Liang Zhou
Keyword(s):  
Cyclic Loading ◽  
Numerical Simulations ◽  
Ultimate Strength ◽  
Beam Model ◽  
Thin Wall ◽  
Cyclic Bending ◽  
Box Beam ◽  
Bending Loads ◽  
Thin Walled

The aim of this paper is to study the ultimate strength of a thin-wall box beam under cyclic bending loads. The nonlinear numerical simulations have been performed on the cyclic behaviors of a thin-walled box beam to investigate the ultimate strength and accumulative plastic deflection effect. Four cyclic loading cases are analyzed in the numerical simulations for the Fukumoto B-60-1 box beam model. The results of the simulations by the paper are discussed and they shall provide some valuable information to further study on the problem.

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