On a new algorithm for time step integration of nonlinear systems

A new implicit algorithm for time step integration of finite element structural dynamic equations is presented. Convergence, stability and numerical damping properties are discussed. Due to the way nonlinear structural behavior is taken into account, the algorithm is expected to compare favorably with existing ones. Some simple numerical results are presented. A related explicit algorithm is also derived and shortly discussed

Homogenization and seismic assessment : review and recent trends

The mechanics of masonry structures has been for long underdeveloped in comparison with other fields of knowledge. Presently, non-linear analysis is a popular field in masonry research and advanced computer codes are available for researchers and practitioners. The chapter presents a discussion of masonry behaviour and clarifies how to obtain the non-linear data required by the computations. The chapter also addresses different homogenisation techniques available in the literature in the linear and rigid-plastic case, aiming at defining a catalogue and at discussing the advantages and disadvantages of the different approaches. Special attention is given to stress assumed models based either on a polynomial expansion of the micro-stress field or in the discretization of the unit cell by means of a few constant stress finite elements CST with joints reduced to interfaces. Finally, the aspects of seismic assessment are presented and case studies involving the use of macro-block analysis, static (pushover) analysis and time integration analysis are discussed.(undefined

Leaving the Planar Universe

A computer program is presented which generates realistic images of planned buildings embedded in their future environment through photomontage. The planar universe of conventional photomontaging is extended to three dimensions. During an interactive preprocessing step, a three- dimensional model of the building's environment is created: Geometrical data is retrieved photogrammetrically from a number of site photographs. Atmospheric parameters and the relative weights of the components of natural daylight are also retrieved from the photographs. The final image, combining the artificial model of the building and the photographs of its surroundings, is rendered by an extended ray-tracing algorithm in three-dimensional object space