System behaviour in prestressed concrete T-beam bridges

About 70 prestressed concrete T-beam bridges, constructed in the Netherlands between 1953–1977, are still in use today with many located in the main highway network. This type of bridge consists of prefabricated and prestressed T-shaped beams, with an integrated deck slab, cross-beams and transverse prestressing. Even if these bridges are well...

Narrow Vertical Mortar Connections for Precast Concrete Shear Walls

The thixotropic properties of contemporary mortars allow the insertion of mortar in small vertical seams by using a mortar pump without the need for traditional formwork. In such a seam, a vertical mortar connection for the transfer of shear forces can be created by simply adding a profile to the mortar-to-concrete interfaces. In this way a...

Heat-affected zone in welded cold-formed rectangular hollow section joints

High-strength steel (HSS) has higher strength but lower ductility than mild steel. The cross-section of the structural members may be reduced using HSS instead of mild steel, provided the buckling of elements does not govern the failure. The reduced member size benefits the environment and economy by means of less energy consumption, less carbon...

Acoustic emission-based indicators of shear failure of reinforced concrete structures without shear reinforcement

Existing concrete bridges require efficient assessment due to increasing traffic load and degrading material. For reinforced concrete structures without shear reinforcement, a typical failure mode is shear, which often means a total loss of structural capacity and does not have an obvious warning beforehand. To indicate the shear failure before...

Shear failure of prestressed girders in regions without flexural cracks

In the design process of prestressed bridges and viaducts, the required amount of shear reinforcement is determined with a model that assumes the presence of flexural cracks. In order to keep the design process simple, this model is also prescribed to determine the amount of shear reinforcement for the regions of the structure in which, at the...

Towards a systematic design approach of D-regions in reinforced concrete: Optimization-based generation of Strut-and-Tie models

Reinforced Concrete (RC) structures are widely used in our society for more than a century. In order to design safe and economical RC structures, various methods have been proposed by engineers and researchers. Remarkably, it still is a challenging task for engineers to design D-regions of RC structures, regions with nonlinear strain...

Simulating quasi-brittle failure in structures using Sequentially Linear Methods: Studies on non-proportional loading, constitutive modelling, and computational efficiency

Sequentially Linear Analysis (SLA) is a proven robust alternative to incremental-iterative solution methods in nonlinear finite element analysis (NLFEA) of quasi-brittle specimen. The core of the method is in its departure from a load, displacement or arc-length driven incremental approach (aided by internal iterations to establish equilibrium)...

Efficient reliability analysis of concrete structures on the basis of non-linear finite element analysis under numerical noise

The analytical expressions for the ultimate load bearing capacity of the RC structures do not provide the generalized notion of ultimate load bearing capacity, which can be obtained through nonlinear finite element analysis (NLFEA). In order to obtain an accurate estimate of failure probability of a RC structure it is necessary to use NLFEA...

Sequentially linear analysis for simulating brittle failure

The numerical simulation of brittle failure at structural level with nonlinear finite<br/>element analysis (NLFEA) remains a challenge due to robustness issues. We attribute these problems to the dimensions of real-world structures combined with softening behavior and negative tangent stiffness at local level which may lead to non-convergence, i...

The Deteriorating Impact of Alkali-Silica Reaction on Concrete: Expansion and Mechanical Properties

The assessment of concrete structures affected by alkali-silica reaction (ASR) is a complex problem due to the multiscale nature of this long-term phenomenon. The reaction starts within the concrete constituents with the formation of an expansive alkali-silica gel at reaction products level. Being the expansive gel confined within the concrete...

Shear beams in finite element modelling: Software implementation and validation

Fiber models for beam and shell elements allow for relatively rapid finite element analysis of concrete structures and structural elements. This project aims at the development of the formulation of such elements and a pilot implementation. The reduction of calculation time and degrees of freedom and the few required input variables are...

Calculation of benchmarks with a shear beam model

Fiber models for beam and shell elements allow for relatively rapid finite element analysis of concrete structures and structural elements. This project aims at the development of the formulation of such elements and a pilot implementation. Standard nonlinear fiber beam formulations do not account for shear effects and cannot capture all failure...

Propagation and band width of smeared cracks

The crack band approach (in the smeared crack concept) is widely used for the modeling of concrete fracture and is an important analysis technique within advanced engineering. However, the simulations can be impeded by mesh-induced directional bias. Cracks prefer to propagate along continuous mesh lines, which causes a dependency of the...

Design and analysis of a large wind floater

Modelling of settlement induced building damage

This thesis focuses on the modelling of settlement induced damage to masonry buildings. In densely populated areas, the need for new space is nowadays producing a rapid increment of underground excavations. Due to the construction of new metro lines, tunnelling activity in urban areas is growing. One of the consequences is a greater attention to...

Computational Modeling on Concrete, Masonry and Fiber-reinforced Composites: Proceedings of the Workshop on 17 – 18 June 2009, Delft, The Netherlands

This booklet comprises the extended abstracts to be presented at the Ma(gni)FiCo workshop held in Delft, The Netherlands, on 17-18 June 2009. The spirit of this workshop is to have a small gathering with ample time for lively conversation and interaction among the student and faculty researchers. As a partial acronym, Ma(gni)FiCo stands for a...

Finite-element modelling of stress development and fault reactivation in and around a producing gas reservoir: quantification of calculation results in DIANA

Stress changes related to the depletion of gas reservoirs in the northern Netherlands can lead to small seismic events. Field data analysis makes it very likely that these events are the result of reactivation of existing faults or joints in or near the reservoirs. DIANA is used to model 3D gas reservoirs, in order to analyse stress development...