Generalized warping and distortional analysis of curved beams with isogeometric methods

- A spatial prismatic curved beam element of arbitrary composite cross section is proposed.
- Curvature effect is considered in the generalized warping and distortional analysis.
- The numerical solution is based on Isogeometric tools combined either with FEM or BEM.
- The cross sectional analysis is based on an iterative equilibrium scheme.
- User can set the desirable number of deformation modes considered in the cross section analysis.

Towards improving conventional beam elements in order to include distortional effects in their analysis, independent parameters have been taken into account in this study. Curved beam's behavior becomes more complex, even for dead loading, due to the coupling between axial force, bending moments and torque that curvature produces. Thus, the importance of simulating geometry exactly arises in order to approximate accurately the response of the curved beam. For this purpose, the isogeometric tools (b-splines and NURBS), either integrated in the Finite Element Method (FEM) or in a Boundary Element based Method (BEM) called Analog Equation Method (AEM), are employed in this contribution for the static analysis of horizontally curved beams of open or closed (box-shaped) cross sections. Responses of the stress resultants, stresses and displacements to static loading have been studied for various cross sections.