The measurement of frequency response functions (FRFs) on nominally identical items reveals usually a considerable scatter induced by some inherent variabilities. In this paper a stochastic parametric approach is suggested in order to analyze the variability of the FRFs, where random as well as uncertain structural properties are modeled as a function of independent random variables with prescr...

In this paper a new approach is taken to identify a crack in a simply supported plate undergoing free vibration. The approach uses a Markov-Chain MonteCarlo implementation of Bayes’ Rule to identify the presence of a crack and, more importantly, to estimate crack parameters; the process also provides confidence intervals for those parameters. To generate the required time series, a semi-analyti...

Elastic boundary eigensolution problems are converted into boundary integral equations by potential theory. The kernels of the boundary integral equations have both the logarithmic and Hilbert singularity simultaneously. We present the mechanical quadrature methods for solving eigensolutions of the boundary integral equations by dealing with two kinds of singularities at the same time. The meth...

We describe a fully-vectorial, three-dimensional algorithm to compute the definite-frequency eigenstates of Maxwell's equations in arbitrary periodic dielectric structures, including systems with anisotropy (birefringence) or magnetic materials, using preconditioned block-iterative eigensolvers in a planewave basis. Favorable scaling with the system size and the number of computed bands is exhi...

An iterative procedure is presented for computing eigenvector sensitivities due to finite element model parameter variations. The present method is a Preconditioned Conjugate Projected Gradient-based technique and is intended to utilize the existing matrix factorizations developed for an iterative eigensolution such as Lanczos or Subspace Iteration. As such, this technique can be integrated int...

With the use of the Laplace integral transformation and state space formalism, the classical axial symmetric quasistatic problem of viscoelastic solids is discussed. By employing the method of separation of variables, the governing equations under Hamiltonian system are established, and hence, general solutions including the zero eigensolutions and nonzero eigensolutions are obtained analytical...