## Optimal design of elastic arches in combination with bifurcation theory

Germany

Germany

Germany

Consider an infinite trough (or wedge) with dihedral angle 2#alpha#, 0 #pi#/2 the cylinder configuration is unstable and bifurcation occurs. We exhibit the full family of bifurcating solutions starting with the round cylinder solution and proceeding through a ''beading up'' process into a series of spherical sections suitably positioned. Furthermo...

Germany

The dynamic behaviour of the L-H transition in ASDEX-Upgrade is described. We focus on the periodic L-H-L transitions known as 'dithering H-mode' and show that there is an intrinsic timescale in this process which is characteristic for the L-H transition. We give a tentative explanation for the phenomenon using an extension of Itoh's model for the ...

The deformation of a bow-shaped I-beam with variable cross section under a constant load is described by a system of nonlinear differential equations. The width of the beam is determined optimal such that the deformation is minimal or the critical load is maximal. To compute the critical load, i.e., the smallest positive symmetric bifurcation point...