Optimization of stiffened panels considering geometric nonlinearity

TOPOLOGY OPTIMIZATION OF PRETENSIONED CONCRETE BEAMS CONSIDERING MATERIAL NONLINEARITY

In this paper, the bi-directional evolutionary structural optimization (BESO) method is used to find optimal layouts of 3D prestressed concrete beams. Considering the element sensitivity number as the design variable, the mathematical formulation of topology optimization is developed based on the ABAQUS finite element software package. The surface-to-surface contact with a small sliding between...

Convex and Probabilistic Models for the Uncertainties in Geometric Imperfections of Stiffened Composite Panels

Optimization of Composite, Stiffened, Imperfect Panels under Combined Loads for Service in the Postbuckling Regime

Local buckling and postbuckling of panels stiffened by stringers and rings and subjected to combined in-plane loads is explored with the use of a single module model that consists of one stringer and a width of panel skin equal to the stringer spacing. The cross-section of the skin-stringer module is discretized and the displacement field is assumed to vary trigonometrically in the axial direct...

Design optimization of stiffened composite panels with buckling and damage tolerance constraints

The design of stiffened, composite wing panels must satisfy a range of requirements related to performance, economy and safety. In particular, the design must be damage tolerant to satisfy a number of different performance requirements for various states of damage. To obtain an optimum configuration that satisfies these requirements simultaneously, optimization code PANOPT was extended with a m...

Fracture Analysis of the Faa/nasa Wide Stiffened Panels

This paper presents the fracture analyses conducted on the FAA/NASA stiffened and unstiffened panels using the STAGS (STructural Analysis of General Shells) code with the critical crack-tip-opening angle (CTOA) fracture criterion. The STAGS code with the “plane-strain” core option was used in all analyses. Previous analyses of wide, flat panels have shown that the high-constraint conditions aro...