Shear strain effects on flexure and torsion of thin-walled pultruded composite beams

1999 ◽  
Vol 26 (6) ◽  
pp. 852-868 ◽  
Author(s):  
Mohammad Z Kabir ◽  
Archibald N Sherbourne
Keyword(s):  
Shear Strain ◽  
Theoretical Study ◽  
Fibre Orientation ◽  
Twist Angle ◽  
Structural Response ◽  
Beam Theory ◽  
Composite Beams ◽  
Vertical Deflection ◽  
Vertical Displacements ◽  
Thin Walled

The paper presents a theoretical study on the static structural response of thin-walled composite open-section beams. Based on a Vlasov-type linear hypothesis, a beam theory is formulated in terms of in-plane elastic properties to analyze composite I and channel section pultruded beams which includes the transverse shear deformation of the beam cross section. The importance of the shear influence on the total vertical deflection is reported. Symmetric lay-up composite beams result in a bending-twisting structural coupling. The optimal fibre orientation for minimizing vertical displacements and twist angle is also investigated.Key words: pultruded, shear strain, composite beams, twist.

Generalised Beam Theory for composite beams with longitudinal and transverse partial interaction

2016 ◽  
Vol 22 (10) ◽  
pp. 2011-2039 ◽  
Author(s):  
Gerard Taig ◽  
Gianluca Ranzi
Keyword(s):  
Structural Response ◽  
Beam Theory ◽  
Element Model ◽  
Composite Beams ◽  
Cross Sectional ◽  
Shear Connections ◽  
Dynamic Analyses ◽  
Partial Interaction ◽  
Deformation Modes ◽  
Generalised Beam Theory

This paper presents a Generalised Beam Theory formulation to study the partial interaction behaviour of two-layered prismatic steel–concrete composite beams. The novelty of the proposed approach is in its capacity to handle the deformability of the shear connections at the interface between the slab and steel beam in both the longitudinal and transverse directions in the evaluation of the deformation modes. This method falls within a category of cross-sectional analyses available in the literature for which a suitable set of deformation modes, including conventional, extension and shear, is determined from dynamic analyses of discrete planar frame models representing the cross-section. In this context, the shear connections are modelled using shear deformable spring elements. As a result, the in-plane partial shear interaction behaviour is accounted for in the planar dynamic analysis during the evaluation of the conventional and extension modes, while the longitudinal partial interaction behaviour associated with the shear modes is included in the out-of-plane dynamic analyses. In the case of the conventional modes, the longitudinal slip is accounted for in the post-processing stage where the warping displacements are determined. A numerical example of a composite box girder beam is presented and its structural response investigated for different levels of shear connection stiffness in both the longitudinal and transverse directions. The accuracy of the numerical results is validated against those obtained with a shell finite element model implemented in ABAQUS/Standard software.

scholarly journals GBT-Based Structural Analysis of Elastic-Plastic Thin-Walled Members

2019 ◽  
Author(s):  
Miguel Abambres ◽  
Dinar Camotim ◽  
Nuno Silvestre
Keyword(s):  
Finite Element ◽  
Structural Response ◽  
Beam Theory ◽  
High Strength ◽  
Elastic Plastic ◽  
Collapse Mechanisms ◽  
Non Linear ◽  
Steel Grades ◽  
Thin Walled ◽  
Shell Finite Element

Structural systems made of high-strength and/or high-ductility metals are usually also rather slender, which means that their structural behavior and ultimate strength are often governed by a combination of plasticity and instability effects. Currently, the rigorous numerical analysis of such systems can only be achieved by resorting to complex and computationally costly shell finite element simulations. This work aims at supplying to designers/researchers an efficient and structurally clarifying alternative to assess the geometrically and/or materially non-linear behavior (up to and beyond the ultimate load) of prismatic thin-walled members, such as those built from cold-formed steel. The proposed approach is based on Generalized Beam Theory (GBT) and is suitable for members exhibiting arbitrary deformation patterns (e.g., global, local, distortional, shear) and made of non-linear isotropic materials (e.g., carbon/stainless steel grades or aluminum alloys). The paper begins by providing a critical overview of the physically and geometrically non-linear GBT formulation recently developed and validated by the authors (Abambres et al. 2012a), which is followed by the presentation and thorough discussion of several illustrative numerical results concerning the structural responses of 4 members (beams and columns) made of distinct (linear, bi-linear or highly non-linear) materials. The GBT results consist of equilibrium paths, modal participation diagrams and amplitude functions, stress contours, displacement profiles and collapse mechanisms some of them are compared with values obtained from ABAQUS shell finite element analyses. It is shown that the GBT modal nature makes it possible (i) to acquire in-depth knowledge on the member behavioral mechanics at any given equilibrium state (elastic or elastic-plastic), as well as (ii) to provide evidence of the GBT computational efficiency, which is achieved by excluding from the analyses all the deformation modes that do not play any role in a particular member structural response.

Finite element investigation into the torsion test in the range of large strains and deformations

2001 ◽  
Vol 36 (4) ◽  
pp. 401-409
Author(s):  
X Peng ◽  
Y Qin ◽  
R Balendra
Keyword(s):  
Finite Element ◽  
Shear Stress ◽  
Shear Strain ◽  
Twist Angle ◽  
Large Strains ◽  
End Effect ◽  
Stress Strain ◽  
Strain Relationship ◽  
Thin Walled ◽  
Tubular Specimens

Torsion tests with thin-walled tubular, solid cylindrical and Lindholm-type tubular specimens were simulated using the finite element code ABAQUS, in the range of large strains and deformations. The results showed that for thin-walled tubular and solid cylindrical specimens the radii of the specimens almost remained straight during torsion; for Lindholm-type tubular specimens the twist angle of the cross-section at the two ends of the gauge section did not stay constant, due to the change of the specimen geometry (i.e. the end effect). A correction which considers the end effect should therefore be introduced when the stress-strain relationship is characterized. Compared with the stress-strain relationship obtained previously from experiment, a distinct difference was noted when conventional formulae were used to convert the torque and twist angle into the shear stress and shear strain. Further, the influence of axial constraint conditions at the two ends of the specimen was examined; the results showed that axial strains and stresses had no significant influence on the definition of the shear stress-shear strain relation, and hence these can be neglected when the stress-strain relationship is characterized.

A beam theory for thin-walled composite beams

1988 ◽  
Vol 32 (4) ◽  
pp. 265-277 ◽  
Author(s):  
L.C. Bank ◽  
P.J. Bednarczyk
Keyword(s):  
Beam Theory ◽  
Composite Beams ◽  
Thin Walled

Dynamic Response of Thin-Walled Composite Material Timoshenko Beams

1990 ◽  
Vol 112 (2) ◽  
pp. 149-154 ◽  
Author(s):  
L. C. Bank ◽  
C.-H. Kao
Keyword(s):  
Natural Frequencies ◽  
Fiber Composite ◽  
Beam Theory ◽  
Composite Beams ◽  
Mode Shapes ◽  
Structural Members ◽  
Timoshenko Beams ◽  
Conventional Steel ◽  
Thin Walled ◽  
Offshore Industry

Thin-walled structural members are used extensively in the offshore industry in applications ranging from marine risers to platforms and frames. Advanced fiber composite structural members may offer advantages over their conventional steel counterparts in certain situations. Use of composite members will require modifications to existing structural analysis codes. This paper presents a beam theory for thin-walled composite beams that can be incorporated into existing codes. Timoshenko beam theory is utilized to account for shear deformation effects, which cannot be neglected in composite beams, and for the variability in material properties in different walls of the beam cross section. The theory is applied to the analysis of the free vibration problem and shows the dependence of the natural frequencies and mode shapes on the in-plane properties of the laminates that form the walls of the beam. Forced periodic and forced arbitrary problems are also discussed and the deflected shapes and maximum deflections are shown as functions of wall layups.

Post-buckling inelastic analysis of thin-walled metal members using the Generalised Beam Theory

2019 ◽  
Author(s):  
Miguel Abambres ◽  
Dinar Camotim ◽  
Miguel Abambres
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Beam Theory ◽  
Flow Theory ◽  
Promising Alternative ◽  
Inelastic Analysis ◽  
Post Buckling ◽  
Thin Walled ◽  
Shell Finite Element ◽  
Generalised Beam Theory

A 2nd order inelastic Generalised Beam Theory (GBT) formulation based on the J2 flow theory is proposed, being a promising alternative to the shell finite element method. Its application is illustrated for an I-section beam and a lipped-C column. GBT results were validated against ABAQUS, namely concerning equilibrium paths, deformed configurations, and displacement profiles. It was concluded that the GBT modal nature allows (i) precise results with only 22% of the number of dof required in ABAQUS, as well as (ii) the understanding (by means of modal participation diagrams) of the behavioral mechanics in any elastoplastic stage of member deformation .

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