Elastodynamic analysis of low tension cables using a new curved beam element

AbstractIn this paper, we address and overcome the difficulties associated with the use of the classic cable theory to treat low tension cables by developing a new three-noded locking-free nonlinear curved beam element. Based upon nonlinear generalized curved beam theory, large deformations and rotations in the new element are formulated in terms of Updated Lagrangian framework. Consistently coupled polynomial displacement fields are used to satisfy the membrane locking-free condition and the requirement of being able to recover the inextensible bending modes. Quintic transverse displacement interpolation functions are used to represent the bending deformation of the beam, while the axial and torsional displacement fields are derived by integration of the presumably linear membrane and torsional shear strain fields, which are coupled with the transverse displacement fields. Numerical results are presented to demonstrate the superior accuracy and the high convergence rate of the newly developed curved beam element. The stability and accuracy of the new element are further validated by experiments of an instrumented free-swinging steel cable experiencing slack and low tension. Good agreements in cable position and tension are observed between the experimental results and the finite element predictions

On the parameters which govern the symmetric snap-through buckling behavior of an initially curved microbeam

In this paper, we extend the earlier studies to investigate the effects of various parameters which govern the symmetric snap-through buckling of an initially curved microbeam subject to an electrostatic force. The governing formulations are developed using Euler–Bernoulli beam theory. The mid-plane stretching experienced during the snap-through buckling is considered using von Karman nonlinear strain, and the nonzero strain component is determined and solved using Galerkin decomposition approach. The studied parameters include: beam fixation type (double-clamped and simply-supported), arch shape, residual axial force, and uniform temperature variation. The results of our work reveal the significant effects of the type of the beam fixation, the residual force, and the temperature variation on the criterion for the symmetric snap-through buckling of microbeams, while the effect of the arch shape is somewhat insignificant

Effects of wavy sidewall on vortex breakdown in an enclosed cylindrical chamber with a rotating end wall

10.1063/1.3072090Physics of Fluids211-PHFL