9 documents found, page 1 of 1
Assessing static and dynamic response variability due to parametric uncertainty...
Carvalho, Alda; Silva, Tiago A. N.; Ramos Loja, M.A.Composite structures are known for their ability to be tailored according to specific operating requisites. Therefore, when modelling these types of structures or components, it is important to account for their response variability, which is mainly due to significant parametric uncertainty compared to traditional materials. The possibility of manufacturing a material according to certain needs provides greater...
Assessing static and dynamic response variability due to parametric uncertainty...
Carvalho, Alda; Silva, Tiago A. N.; Loja, M.A.R.Composite structures are known for their ability to be tailored according to specific operating requisites. Therefore, when modelling these types of structures or components, it is important to account for their response variability, which is mainly due to significant parametric uncertainty compared to traditional materials. The possibility of manufacturing a material according to certain needs provides greater...
On the use of measured rotational responses in structural dynamic analysis
Silva, Tiago A. N.; Almeida, Raquel A. B.; Urgueira, António P. V.Testing is a very important task in structural dynamics and on its applications, namely on the characterization of the dynamic behaviour of structures or on the use of the structural responses to indirectly determine dynamic properties or parameters. The increasing availability of sensors, capable of measuring rotational responses, leads to the improvement of existing methods and to the development of new ones ...
Selection of modelling parameters for stochastic model updating
Silva, Tiago A. N.; Mottershead, John E.In structural dynamics, the adjustment of a set of modelling parameters based on the minimization of the discrepancy between experimental and model responses is known as model updating. In the context of stochastic model updating, the selection of a set of updating parameters from the modelling ones is very important, both in terms of computational efficiency and of the accuracy of the solution of this stochast...
A global optimization approach based on adaptive populations
Silva, Tiago A. N.; Loja, Amélia; Carvalho, Alda; Maia, Nuno M. M.; Barbosa, JoaquimThe solution of inverse problems based on experimental data is itself an important research issue. In this context and assuming that an experimental sample is available, rather than trying to find a specific deterministic solution for the inverse problem, one aims to determine the probabilistic distribution of the modelling parameters, based on the minimization of the dissimilarity between the empirical cumulat...
On the characterization of parametric uncertainty on FGM plates
Damásio, Fábio R.; Silva, Tiago A. N.; Carvalho, Alda; Loja, AméliaComposite materials with their intrinsic tailor-made capabilities can be strong candidates to improve the mechanical performance of structures, either by partially or totally replacing other traditional materials. These easily tailored features can be thought not only in terms of the more often used fibre reinforced laminated composites but also in the context of particulate composites. In general, the mechanic...
Thermal Residual Stresses in Functionally Graded Structures: a Didactic Case Study
Silva, Tiago A. N.; Loja, AméliaManufacturing processes which involve plastic deformations or abrupt temperature gradients often leads thermal residual stresses to arise on materials. This fact can thus result in stress states that remain within a structural member in the absence of external loads, being desirable to obtain, as long as possible, a minimum level of residual stresses as well as smoother stresses transitions in the materials int...
A model updating technique based on FRFs for damped structures
Silva, Tiago A. N.; Maia, N. M. M.; Barbosa, JoaquimModel updating methods often neglect that in fact all physical structures are damped. Such simplification relies on the structural modelling approach, although it compromises the accuracy of the predictions of the structural dynamic behaviour. In the present work, the authors address the problem of finite element (FE) model updating based on measured frequency response functions (FRFs), considering damping. The...
Elastically restrained Bernoulli-Euler beams applied to rotary machinery modelling
Silva, Tiago A. N.; Maia, Nuno M. M.Facing the lateral vibration problem of a machine rotor as a beam on elastic supports in bending, the authors deal with the free vibration of elastically restrained Bernoulli-Euler beams carrying a finite number of concentrated elements along their length. Based on Rayleigh's quotient, an iterative strategy is developed to find the approximated torsional stiffness coefficients, which allows the reconciliation b...