Experimental modal validation of a semi-analytical method for assessing dynamic behaviour of flood gates

A new semi-analytical model is developed to predict the dynamic response of slender gates in combination with an overhang, which are subjected to standing waves. Still little is known for these types of gates for this specific forcing type. The semi-analytical model is still in its development phase and must be validated on its performance. This...

One‐way shear strength of wide reinforced concrete members without stirrups

The calibration of most analytical models that assess the shear strength of wide reinforced concrete members without shear reinforcement is based on simply supported beam tests, which may not be representative of slabs and wide members failing in shear. This paper addresses the knowledge on the shear strength of wide members, identification of...

Lattice Fracture Model for Concrete Fracture Revisited: Calibration and Validation

The lattice fracture model is a discrete model that can simulate the fracture process of cementitious materials. In this work, the Delft lattice fracture model is reviewed and utilized for fracture analysis. First, a systematic calibration procedure that relies on the combination of two uniaxial tensile tests is proposed to determine the input...

Applicability of the goda–takahashi wave load formula for vertical slender hydraulic structures

Vertical slender hydraulic structures such as sluices, navigation locks, or storm-surge barriers are often dynamically loaded by waves. For a safe and economic design, an accurate description of the wave loads is needed. A widely used formula for this purpose is the Goda–Takahashi wave load formula (GT). It was derived for the assessment of...

Optimization of steel plate girders in bending: Using FEM-analyses on S690 and S890 steel plate girders

A parametric study, using the FEM-software package ABAQUS, validated on experimental results found by Abspoel, was conducted on S690 steel plate girders to address if the results of the previous researches was valid. Using a slightly different analytical model the results show the maximum web slenderness of this steel grade in both 6000 mm2 and...

Technical feasibility of a quick bridge replacement strategy with minimal traffic hindrance: On the retainment of existing foundations and the application of Advanced Cementitious Materials in an Accelerated Bridge Construction method

Bridges are a crucial part of the dense Dutch highway network. Almost 50% of the current bridges are built between 1960 and 1980 for an intended service life of 50 years and thus they might reach the end of their lifetime in the near future. This strongly indicates that a large challenge can be expected regarding infrastructural replacement.<br/...

Oscillations of a string on an elastic foundation with space and time-varying rigidity

The dynamics of a string on an elastic foundation with time- and coordinate-dependent coefficients have been studied. Asymptotic solutions have been constructed for the following cases: for an arbitrary value of the elastic foundation coefficient at small and large time values, and for small and large coefficients of the elastic foundation at...

Slender Spring Systems, for a close-to-body dynamic arm support for people with Duchenne muscular dystrophy

The goal of this dissertation is to develop a wearable, passive, dynamic arm support that provides users with Duchenne muscular dystrophy (DMD) with support to perform activities of daily living. The arm support needs to be inconspicuous and not stigmatizing, to encourage the users to participate in social activities. Ideally, the device fits...

Laser measurements on experiments on plate girders with a very slender web under pure bending

This paper is about the laser measurements as part of the research on the distribution of a certain amount of steel over the flanges and the web of an I-shaped plate girder to achieve the maximum bending moment resistance [1]. In many steel structures standard hot-rolled sections are used. These sections are divided into specific types in Europe...

Towards slender, innovative concrete structures for replacement of existing viaducts

A majority of the bridges and viaducts in the Netherlands were built in the sixties and seventies of the last century and many of them will need to be replaced in the near future due to technical or functional reasons. This is a replacement issue, faced by many countries worldwide. But what about the concrete structures? Should we replace them...

Optimisation of plate girders

In many steel structures like buildings, industrial halls and bridges, standardized hot-rolled sections are used. These sections are divided into specific types in Europe and similar profiles in the USA. The range of hot-rolled sections is limited and therefore fabricated plate girders are used when the standard hot-rolled sections do not meet...

Semi-analytical method of buckling strength prediction for plates stiffened with T-shaped stiffeners having slender (class 4) webs

A master thesis about stiffening plates with very slender stiffeners is presented. The master thesis represents a completion of my master studies and is written in order to qualify for the degree of M.Sc., Master of Science in Structural Engineering at Delft University of Technology. Current work is done in close collaboration with Iv-Consult,...

Trillingen van betonnen voetgangersbruggen / Vibrations of concrete footbridges

Nowadays more and more slender concrete footbridges are designed. Footbridges are designed thinner to increase esthetic value, as well as incorporate sustainability and to reduce building costs, with a consequence that the eigenfrequency of the bridge can drop so low that it may fall into a range of frequencies that is susceptible to vibrations...

Enhancement of AlN Slender Piezoelectric Cantilevers Actuation by PECVD Silicon Nitride Coating

Actuation enhancement for AlN piezoelectric cantilevers is achieved by coating slender AlN beams with a thin PECVD silicon nitride (SiN) layer. Very good linearity and high deflection, up to 19 nm/V of actuation deflection for 200 ?m long cantilevers, at quasi-static mode, is obtained for a 500 nm SiN top layer. This value is three times larger...

Mega Floating Concrete Bridges

Introduction This graduation project has been initiated to research the technical feasibility of floating bridges. The project has been done in co-operation with the FDN engineering company and Delft technical university. A design is made of a continuous pontoon floating bridge, which connects a mainland to an island. Floating bridges can be...

Computational aerodynamics of ordered vortex flows

The physical aspects, the mathematical modeling, the development and application of computational methods for the simulation of vertical flows are described. The high-Reynolds number vortex flows considered are assumed to be steady, sub-critical and such that the structure of the flow is well-ordered and consists of thin shear layers and slender...

A method for computing the three—dimensional flow about wings with leading—edge vortex separation Part II: Description of computer program VORSEP

In part I of this report a method is described for computing the incompressible flow about slender, thin wings with leading-edge vortex separation. It is assumed that both the wing and the flow field are symmetric with respect to the x—z plane. The method can handle delta—like wings of quite general planform and shape. However, in the...

Reynolds number effects on pressure and normal force distributions along conically pointed circular cylinder at free-stream mach number of 2.3

Pressure measurements have been carried out on 5 stations along a 7.5- caliber conically pointed circular cylinder at a Mach number of 2.3 and Reynolds numbers of 1.2; 4.8 and 11.1 x 106. Pressure distributions have been integrated to produce local normal force coefficients. Some pitot pressure surveys have been performed in the external flow...