Search results for "Bending"
showing 10 items of 244 documents
Simplified Procedure for Evaluating the Effects of Creep and Shrinkage on Prestressed Concrete Girder Bridges and the Application of European and Nor…
2013
The effects of time-dependent phenomena on concrete prestressed girder bridges are investigated. The study concerns the case of bridges built directly in their final configuration and that of bridges built by a sequence of stages in which geometry, restraints, and loads vary until the final configuration is achieved. An analytical approach based on the principles of aging linear viscoelasticity and the age-adjusted effective modulus method is followed. The paper has two aims: the first is to provide an efficient and simplified tool for the evaluation of the structural response in the early stages of design; the second is to compare the results of the analyses on actual cases of bridges when…
Dimensionless analysis of RC rectangular sections under axial load and biaxial bending
2012
This paper proposes a numerical procedure able to provide ultimate curvature and moment domains of rectangular RC sections subjected to combined axial load and biaxial bending. The formulation is carried out in dimensionless terms in order to give results that are valid for classes of sections characterized by the same values of the geometric and mechanical parameters governing the section response. The role of some of these parameters is investigated here. The results show possible correlations linking the actual values of moment and curvature to the values corresponding to two cases of uniaxial bending to be considered separately. © 2012 Elsevier Ltd.
RC column externally strengthened with RC jackets
2013
In this paper the behaviour in compression of RC columns externally strengthened with concrete jacketing is analysed and a cross-section analysis of the jacketed member under axial load and bending moment is developed. The focus was to study the effect of confinement of concrete jacket on concrete core and the behaviour of compressed bars with buckling effects. Some other important aspects such as shrinkage, creep, old to new concrete surfaces and bond split effects were not included in the model because: the use of thick non-shrink grout jacket and a well-roughened surface of old-to-new concrete was supposed; long term effects were included though corrective coefficients for monolithic beh…
Fatigue Design Methodology for Large Mooring Chains Subjected to Out-of-Plane Bending
2014
The present paper presents a fatigue life prediction method for chains subjected to tension and Out-of-Plane-Bending (OPB). The investigation was carried out on a high strength mooring chain segment with a diameter of 165 mm and a steel quality R5. Such chains are used in mooring systems for large Floating Production Storage and Offloading (FPSO) units in harsh weather condition. Due to the fact that the mooring chains are pre-tensioned the wave induced displacements will introduce secondary bending effects about the weak axis in the chain links, particularly in the bilge hang-off area. In such chains both conventional tension fatigue and fatigue damage accumulation due to Out-of-Plane-Bend…
Simplified flexural response of steel-fiber reinforced concrete beams
2008
In the present paper, an analytical model is proposed that is able to determine the flexural response of supported beams under four-point bending tests. Cases of normal strength reinforced concrete beams with longitudinal bars in the presence of reinforcing hooked steel fibers and transverse stirrups are considered. A simplified analytical model is presented that is able to calculate the load-deflection curves and the maximum and ultimate deflections occurring in the case of shear or flexure failures. In the case of shear failure, the maximum shear strength of the beams is evaluated by using a recent analytical expression proposed by the author able to account for the shear-to-moment intera…
R.C. columns strengthened by PBO-FRCM under axial force and bending moment
2017
Fabric-Reinforced Cementitious Matrix (FRCM) systems, also known as Textile Reinforced Concrete (TRC) are nowadays widely used as confining material to enhance both strength and deformation capacity of columns of seismic resistant r.c. frames. In the past, when carbon fiber was used in the textile, experimental results showed that the efficiency of the wrapping is limited by the connection between substrate and fiber, which is not as effective as when epoxy resins are used. To improve the strength of the connection between fibres and mortar binder in FRCM system, the use of p-Phenylene BenzobisOxazole (PBO), having a molecular structure capable of establishing chemical bonds with hydrated c…
An analysis of interface delamination mechanisms in orthotropic and hybrid fiber-metal composite laminates
2007
Abstract The onset and propagation of interlaminar defects is one of the main damage mechanisms in composite materials. This is even more the case when considering layered materials comprising metallic laminae (typically Aluminium) and FRP laminae. Propagation of delamination mainly depends on the initial crack extension and its loading mode. This work presents some results of a combined analytical–numerical–experimental study on the onset and propagation mechanisms regarding interlaminar defects. Two cases have been analysed in particular, the first consisting of a glass-fibre reinforced epoxy resin laminate, and the second consisting of a hybrid laminate where a lamina of aluminium is lay…
Twisting and buckling: A new undulation mechanism for artificial swimmers
2012
Among the various locomotion strategies of the animal kingdom, the undulation locomotion is of particular interest for biomimetic applications. In this paper, we present an artificial swimmer set into motion by a new and non-trivial undulation mechanism, based on the twisting and buckling of its body. The swimmer consists of a long cylinder of ferrogel which is polarized transversely and in opposite directions at each extremity. When it is placed on a water film and submitted to a transverse oscillating magnetic field, the worm-like swimmer undulates and swims. Whereas symmetry breaking is due to the field gradient, the undulations of the worm result from a torsional buckling instability as…
Virtual simulation of an osseointegrated trans-humeral prosthesis: A falling scenario
2018
Abstract Introduction Traditional prosthetic solutions expose the amputee to numerous problems that limit his ability to safely perform the normal activities of daily life. In order to eliminate the problems related to the use of the traditional prosthesis with socket, a new technique was developed for fixing the prosthesis to the amputees based on the principle of osseointegration. The aim of this paper is to study and analyze the stress distribution on the interface between a trans-humeral osseointegrated prosthetic implant and the residual bone, identifying the most stressed areas and thus foreseeing possible failure phenomena of the entire prosthetic system and, after, to compare the st…
Abrupt elastic-to-plastic transition in pentagonal nanowires under bending
2019
MD modeling and calculations were supported by Russian Science Foundation project grant 18-19-00645 “Adhesion of polymer-based soft materials: from liquid to solid”; mechanical testing and FEM simulations were supported by Estonian Research Council projects PUT1689 and PUT1372.