Real crack predictions for reinforced concrete (RC), and especially hybrid reinforced concrete (SFRC), are hard to make for real life engineering projects. In the case of plates (slabs and walls), the strain over a region length is often constant and crack localisation on element level cannot be found. In the new DIANA 10 release it […]

Towards mode selection criteria for multi-mode initial postbuckling analysis of composite cylindrical shells

Initial postbuckling analysis provides a well-established framework to assess the imperfection sensitivity of shell structures. A finite element implementation of the approach makes it possible to analyse the nonlinear buckling behaviour of practical and large shell structures. For structures with complicated nonlinear behavior in which modal interactions are important, such as cylindrical shells, a multi-mode […]

Sequentially linear analysis of fracture under non-proportional loading

Sequentially linear analysis avoids convergence problems typical of non-linear finite element analysis by directly specifying a damage increment instead of a load or displacement increment. A series of linear analyses is used to model highly non-linear behavior without an iterative solution algorithm. The primary contribution herein is the extension of sequentially linear analysis to non-proportional […]

Masonry micro-modelling adopting a discontinuous framework

Several continuous and discontinuous micro-modelling approaches for masonry assemblages are currently under investigation by the authors. The aim is to find a model that provides a suitable description of the material behaviour under compression. Firstly, the behaviour under short-term loading is being considered and, in a later stage, also long-term loading will be addressed. The […]

Improving the quality of structural concrete design

Common practise in concrete design engineering is the sectional design approach. The model should be the most simple choice in this approach and will be often a 1D design model. The design process delivers the generalised moments, forces and displacements. The checks to the actual checking code is on a sectional base, where the section […]

Finite Element Modeling of Early Age Concrete Behavior using DIANA

The main nonlinear phenomena that govern the deformational behavior of early-age concrete are the evolution of the stiffness properties, the development of thermal and shrinkage strains, creep and cracking. In this article, a set of particularly useful features provided by DIANA for this kind of application is presented thanks to the analysis of a purification […]

Analytical implications on in-plane behavior of unreinforced masonry walls

A series of unreinforced masonry (URM) walls were analytically investigated by FEM for a limited version of seismic in-plane performance. For this URM walls were assumed to be continuum and modeled as isotropic plane stress elements within which the nature of cracking was propagated. Accordingly, cracking mode of behavior in URM was modeled by smeared-crack […]

Finite Element Modeling of RC Members Subjected to Shear

A hypo-elastic FEM based model has been proposed, taking into account the shear-transfer mechanism across the smeared cracks. The induced shear stress on the crack surface generates a slippage resulting in unbalanced forces that can be further redistributed throughout the system. Also, the discrete-crack approach has been used for simulation of the experimentally observed slippage […]

Non-linear analysis of prestressed concrete beams with a total strain based model: FEM model and full-scale testing

The load-deformation characteristics and the capacity of prestressed concrete T and double T elements were analysed with the finite element method using DIANA’s total strain based constitutive model. The numerical simulations accompanied two experimental programs. The first program concerned old bridge beam elements strengthened with carbon fiber reinforced polymer plates. The second program concerned beam […]