A discrete model for cyclic mode I loading

AbstractThe cyclic behaviour of a double-edge notched specimen loaded in tension is studied. Cracks in the material are modelled by displacement discontinuities that can propagate during computation. Within these discontinuities, a cohesive zone model is used. The model assumes an additive split of the inelastic jump into a recoverable and an unrecoverable part. The influence of model parameters and discretisation is studied and the results have been compared with experimental data

Proceedings of the International Conference eCAADe: European Computer Aided Architectural Design Education

In the beginning of the eighties, a few enthusiastic researchers, under the impulsion of Tom MAVER (director of the ABACUS group) and Rik SCHIJF (TH Delft) initiated a regular, if not formal, convention of people involved in the teaching of computer aided architectural design ECAADE in Europe. In 1982 a first meeting took place in Delft and, taking into consideration the member of attendants and the enthusiasm during this convention, it was decided that CAAD was definitely an important topic and that a more formal symposium was to be organised in the fall of 1983, in the University of Brussels. The positive evolution of CAAD, not only in educational institutions, but also in professional practice is not surprising: it is to be considered in the global frame of technological and organisational revolution actually taking place. As will be read in the outstanding contribution of the participants it is not a mere choice of increased productivity which attracts the architects, the CAAD techniques also release then from a serious burden: the production of technical drawings and administrative paperwork

Bayesian Statistical Identification of Orthotropic Elastic Constants Accounting for Measurement and Modeling Errors

International audienceBayesian identification provides a framework that can handle both measurement and modeling errors. Furthermore it identifies a probability distribution function thus providing information on both variance and correlation of the identified properties. However, the procedure can be very costly computationally. In order to address the computational cost issue a Bayesian identification procedure based on response surface methodology is proposed. The procedure is illustrated on the problem of identifying orthotropic elastic constants from natural frequencies of a free composite plate. The procedure accounts for measurement noise, uncertainty in other input parameters to the vibration model (plate dimensions, density) as well as systematic error effects. The joint probability distribution of the four elastic ply constants is identified and characterized by mean value and variancecovariance matrix. We find that some properties, such as Poisson's ratio, are identified with much higher uncertainty than other and that significant correlation between the identified properties is present. The developed procedure allowed substantial reduction in computational cost. However, in spite of the cost reduction techniques, it remains at the edge of what is presently reasonable computation time