Surrogate models for optimum design of stiffened composite shells

Stability and vibrations of nonclosed circular cylindrical shells reinforced with discrete longitudinal ribs

“…(13) are of the 10th order because the equations of motion (1) incorporate the stiffness of ribs in bending in the plane equidistant to the tangent to the shell surface. If this stiffness and associated inertial forces were disregarded, Eqs.…”

“…These solutions are inconvenient when there are either few ribs (they lead to ill-conditioned systems of linear algebraic equations) or many ribs (they lead to very large systems of equations). The finite-element method (see, e.g., [8,12,13]) and the finite-difference method (see, e.g., [10]) make the application of single trigonometric series for shells with discrete ribs noncompetitive, unlike analytic methods based on asymptotic methods [2,6,7,9,16,23] or double trigonometric series [2,3,5,6,16]. The latter allow obtaining, in some cases, exact solutions in convenient form to the equations of motion and, as asymptotic methods, simple approximate formulas suitable for analysis of the deformation of shells without labor-intensive calculations.…”

Design and analysis of stiffened composite panels including post-buckling and collapse

“…Collapse is specified by that point of the load-displacement curve where a sharp decrease occurs thus limiting the load-carrying capacity. The POSICOSS team developed fast and reliable procedures for post-buckling analysis of fibre composite stiffened panels, created experimental data bases and derived design guidelines [1,2,[5][6][7][8][9][10][11][12][13][14][15][16][17]. Alternative fast methods were developed also in parallel to the POSICOSS project [17][18][19][20].…”

Application of an iterative global approximation technique to structural optimizations

“…An interesting general discussion of the engineering aspects of the problem can be found in the review provided by Nemeth (Nemeth and Starnes 1998) as well as other more recent works (Arbocz and Starnes 2002). Optimization strategy have been recognized as a promising approach to this problem since the late nineties, as in the works by Wiggenraad et al and Nagendra et al (Wiggenraad et al 1998;Nagendra et al 1996) while surface response techniques have been more recently applied by Rikards et al (Rikards et al 2004). However, the efforts of this paper are devoted more in the assessment of an iterative global approximation procedure rather than that in the investigation of composite structures under post-buckling requirements.…”