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Publication - Dr Alberto Pirrera

    Improved Structural Efficiency of a Curved Stiffened Panel Through Modal Nudging


    Carvalho, OL, Groh, R & Pirrera, A, 2019, ‘Improved Structural Efficiency of a Curved Stiffened Panel Through Modal Nudging’., pp. 186


    Recent studies have shown a revival of interest in nonlinearities and instabilities, both as a source of smart functionality and a means for lightweighting. An example of the latter is the recently introduced concept of modal nudging, which uses information from the post-buckling regime to tailor the nonlinear response of a structure. The first step in modal nudging consists in finding a stable region of interest in a structure’s equilibrium manifold beyond the first onset of instability. This stable deformation mode is then extracted and seeded into the initial baseline geometry. The new equilibrium path is consequently nudged to the targeted stable region in a manner similar to seeding imperfections. The described strategy can be used to enhance structural performance based on a measure of choice. In the current work, modal nudging is used to improve the load-carrying capacity of a curved stiffened panel under compressive loading. The stable regions of interest are found on the fundamental load path but are naturally unobtainable as they are separated by unstable equilibrium segments. The effects of nudging are analysed within a nonlinear finite element and numerical continuation framework. With manufacturability in mind, the effects of perturbing only certain features of the baseline geometry are also explored. It is observed that, in all cases, the nudged structure can converge to the stable region with greater load-carrying capacity at the expense of a marginal increase in mass due to the small perturbation in initial geometry.

    Full details in the University publications repository