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Predicting the structural response of masonry structures with acceptable accuracy is paramount to safeguard the historical heritage and build new constructions with safety margins adequate to modern standards. However, due to the heterogeneous nature and anisotropic response of masonry, such prediction is still difficult to achieve, where most current masonry representations are based upon homogeneous isotropic material models or even more simplified masonry macro‐elements. In this article, a novel anisotropic constitutive model to be used in detailed 3D continuum FE representations is described. This is based upon the application of the transformed‐tensor method to an isotropic uncoupled plastic‐damage model, which is further enhanced by additional novel features enabling the proper definition of the shear behavior both in terms of yielding surface and damage evolution while increasing local computational robustness. Illustrative examples at different scales are presented, highlighting the characteristics and potential of the developed masonry material model. Focus is placed on the mechanical behavior under uniaxial and biaxial stress states considering pure compression on wallets with varying inclination of the material principal axes and the out‐of‐plane response of wall components. The numerical results confirm the ability of the proposed constitutive model to predict typical masonry anisotropic response characteristics, which cannot be accurately represented by standard isotropic representations commonly used in professional practice and research. [ABSTRACT FROM AUTHOR]

The paper investigates the design of continuous steel-concrete composite beams with compact cross section using the elastic analysis with limited redistribution. The permissible moment redistribution which satisfies the requirements of the ultimate limit state (collapse) and serviceability limit state (crack width in the concrete slab) was computed. An advanced finite element program accounting for all mechanical nonlinearities and time-dependent phenomena (creep and shrinkage of concrete) was used. An extensive parametric analysis aimed to determine the influence of several geometrical parameters on the permissible moment redistribution was carried out on propped cantilevers and fixed-end beams. The analyzed parameters include the shape of the steel profile, the ratio between the depths of concrete slab and steel beam, the steel to concrete area ratio, and the reinforcement percentage of the concrete slab. The analysis was limited to compact steel sections (AISC 360-05) or class 1 steel sections (Eurocode 3) and low ductility reinforcing steel (elongation at maximum load [[epsilon].sub.ru]=2.5%). The moment redistribution domain which satisfies the rotation compatibility in the critical sections, due to the attainment of the rupture of the reinforcement or the local buckling of the steel profile, and the control of cracking ( DOI: 10.1061/(ASCE)ST.1943-541X.0000098 CE Database subject headings: Composite beams; Concrete; Steel; Continuous beams; Bending; Nonlinear analysis; Finite element method; Moment distribution; Cross sections. Author keywords: Composite beams; Concrete; Steel; Continuous beams; Bending moments; Nonlinear analysis; Finite-element method.

The response up to collapse of masonry arch bridges is very complex and affected by many uncertainties. In general, accurate response predictions can be achieved using sophisticated numerical descriptions, requiring a significant number of parameters that need to be properly characterised. This study focuses on the sensitivity of the behaviour of masonry arch bridges with respect to a wide range of mechanical parameters considered within a detailed modelling approach. The aim is to investigate the effect of constitutive parameters variations on the stiffness and ultimate load capacity under vertical loading. First, advanced numerical models of masonry arches and of a masonry arch bridge are developed, where a mesoscale approach describes the actual texture of masonry. Subsequently, a surrogate kriging metamodel is constructed to replace the accurate but computationally expensive numerical descriptions, and global sensitivity analysis is performed to identify the mechanical parameters affecting the most the stiffness and load capacity. Uncertainty propagation is then performed on the surrogate models to estimate the probabilistic distribution of the response parameters of interest. The results provide useful information for risk assessment and management purposes, and shed light on the parameters that control the bridge behaviour and require an accurate characterisation in terms of uncertainty. [ABSTRACT FROM AUTHOR]