Uncertainty Analysis of Mechanical Behavior of Functionally Graded Carbon Nanotube Composite Materials
The remarkable mechanical and sensing properties of carbon nanotubes (CNTs) suggest that they are ideal candidates for high performance and self-sensing cementitious composites. However, there is still a lack of deeper knowledge of the uncertainty associated with their incorporation, concretely in functionally graded composite materials (FGM). The influence of these uncertainties can be critical for future applications in the field of Structural Health Monitoring (SHM), techniques that usually require high accuracy modeling. Most researches restrict the aim of their studies to the analysis of composite materials with uniform or linear grading profiles. This study throws light on the basis of stochastic representation of the grading profiles and analyzes the propagation of its uncertainty into the response of some structural elements. The finite element method (FEM) is employed to study the individual and interactive effects of the mechanical properties (Young’s modulus, density, Poisson’s ratio and CNT’s waviness) and grading profiles. The effects of stochastic uncertainties on the overall properties of the composite material are represented using the probability theory. Numerical results show the influence of these variables in several benchmark cases such as cylindrical, spherical and doubly curved shells, in terms of their static and dynamic characteristics by performing modal analysis.
KeywordsStochastic analysis Kriging metamodel RS-HDMR metamodel Carbon nanotube composites Hu-Washizu principle
This research was supported by Spanish ministry of economy and competitively under the Project Ref: DPI2014-53947-R. E. G-M was also supported by a FPU contract-fellowship from the Spanish Ministry of Education Ref: FPU13/04892.
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