A multi-level analysis of skin/stiffener debonding is used to perform the design of fuselage of future aircraft during postbuckling. The “pyramid of test” approach is used both for experimental and numerical analysis (see Fig 1). The analysis begins with nonspecific element (NASA Specimens), then 7 point-bending tests are performed and the approach is finally validated on real panels of an on-g...

Stretchable electronics that require functional components with high areal coverages, antennas with small sizes and/or electrodes with invisibility under magnetic resonance imaging can benefit from the use of electrical wiring constructs that adopt fractal inspired layouts. Due to the complex and diverse microstructures inherent in high order interconnects/electrodes/antennas with such designs,...

A hybrid Trefftz finite element (HT FE) model fl~r postbuckling analysis of thin plates is presented, based on a modified variational principle. With the aid of incremental form of equilibrium equations, all non-linear terms may be viewed as pseudo-loads, and then the in-plane and out-of-plane equations can be unoccupied. As a consequence, the solution procedure for the postbuekling plate becom...

Embryogenesis offers a real laboratory for pattern formation, buckling, and postbuckling induced by growth of soft tissues. Each part of our body is structured in multiple adjacent layers: the skin, the brain, and the interior of organs. Each layer has a complex biological composition presenting different elasticity. Generated during fetal life, these layers will experience growth and remodelin...

European aircraft industry demands for reduced development and operating costs, by 20% and 50% in the short and long term, respectively. Contributions to this aim are provided by the completed project POSICOSS and the running follow-up project COCOMAT, both supported by the European Commission. As an important contribution to cost reduction a decrease in structural weight can be reached by expl...

GMRES(k) is widely used for solving nonsymmetric linear systems. However, it is inadequate either when it converges only for k close to the problem size or when numerical error in the modified Gram–Schmidt process used in the GMRES orthogonalization phase dramatically affects the algorithm performance. An adaptive version of GMRES(k) which tunes the restart value k based on criteria estimating ...

The main goal of this research is to study the postbuckling behavior nonlocal functionally graded beams. Eringen’s differential model used evaluate influence material length scale in bending response. An improved shear deformation beam theory with five independent parameters utilized, which suitable for use 3D constitutive equations. A finite element derived spectral high-order interpolation fu...

This paper presents a comparison of critical loads for trusses, calculated by linear and nonlinear stability analysis. Analyses are provided by using finite elements method. In linear case, critical load is extracted from derived algebraic eigenvalue problem. In case of nonlinear analysis, critical load is determined by construction of postbuckling equilibrium path. Numerical examples for chara...