Global stability failure of a 3D composite structure accompanied by unavoidable polymorphic uncertainties

Abstract

In this study, a non-linear stability analysis of a carbon fiber reinforced plastic (CFRP) considering unavoidable polymorphic uncertainties is conducted. For the realistic incorporation of the uncertainties in the finite element model, thickness variations and geometrical inaccuracies have been detected in advance by non-destructive testing. For that, a structure made of CFRP has been designed. Additionally, the material parameters have been defined as dependent stochastic variables based on reference studies in the literature. The distinction in aleatory and epistemic uncertainties leads to different uncertainty models and to a computationally costly fuzzy-stochastic analysis. Strains and displacements have been measured in a symmetric three-point bending test and compared to the numerical predictions. In addition to the present uncertain parameters, a case study shows that the fiber volume content and a small pre-deformation should be taken into account to minimize the deviation from the experimental results.

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