Search results for "finite element method"
showing 10 items of 746 documents
Effect of FRP strengthening on the flexural behaviour of calcarenite masonry walls
2017
The use of fiber-reinforced polymers (FRP) for structural strengthening has become increasingly popular in recent years. Several applications of FRP have been proposed and applied, depending on the target of the technique, kind and/or material of the structural member. In particular, because of their great tensile strength, FRP materials are commonly used to enhance the out-of-plane behaviour of masonry walls, allowing to increase their strength, ductility and improving safety against overturning. For these reasons, FRP laminates are often applied in vulnerable ancient buildings in seismic areas to reinforce façades and walls with poor structural features. However, some issues arise when a…
Metallurgical Phenomena Modelling in Friction Stir Welding of Aluminium Alloys: Analytical vs. Neural Network Based Approaches
2008
In this paper, the metallurgical phenomena occurring in friction stir welding processes of AA6082-T6 and AA7075-T6 aluminum alloys are investigated. In particular, to predict the local values of the average grain size, either a simple analytical expression depending on a few material constants or a properly trained neural network is linked to the finite element model of the process. The utilized tools, which take as inputs the local values of strain, strain rate, and temperature, were developed starting from experimental data and numerical results.
Simple algorithms for calculation of the axial‐symmetric heat transport problem in a cylinder
2001
The approximation of axial‐symmetric heat transport problem in a cylinder is based on the finite volume method. In the classical formulation of the finite volume method it is assumed that the flux terms in the control volume are approximated with the finite difference expressions. Then in the 1‐D case the corresponding finite difference scheme for the given source function is not exact. There we propose the exact difference scheme. In 2‐D case the corresponding integrals are approximated using different quadrature formulae. This procedure allows one to reduce the heat transport problem described by a partial differential equation to an initial‐value problem for a system of two ordinary diff…
In-situ NDT testing procedure as an integral part of failure analysis of historical masonry arch bridges
2015
Abstract A nineteenth-century masonry arch bridge was analyzed as an illustrative example to explain the role of in-situ test campaigns in failure analysis and retrofit design. Test results were studied to find out the advantages of each technique, with the aim of proposing an optimized in-situ testing procedure. Standard static penetrometer, flat jack, thermographic and georadar in-situ tests were conducted. Traffic effects were analyzed by means of vibrational tests. The experimental analysis performed to investigate damage on the bridge structures shows the degree of reliability offered by each technique in evaluating specific information and reproducing the global behavior of the struct…
Micro damage and cracking in fibre reinforced composites by a novel hybrid numerical technique
2020
Article number 0033974 AIP Incluida en Conference Proceedings 2309 The prediction of failure mechanisms in fibre-reinforced composite materials is of great importance for the design of composite engineering applications. With the aim of providing a tool able to predict and explain the initiation and propagation of damage in unidirectional fiber reinforced composites, in this contribution we develop a micromechanical numerical model based on a novel hybrid approach coupling the virtual element method (VEM) and the boundary element method (BEM). The BEM is a popular numerical technique, efficient and accurate, which has been successfully applied to interfacial fracture mechanics problems of f…
Mechanical testing and numerical modelling of pull-wound carbon-epoxy spinnaker poles
2002
The paper deals with experimental testing and numerical simulation of the mechanical behaviour of multi-layer cylindrical coupons, of two different diameters, made in carbon-epoxy composite. The aim of the study is to provide a simple and effective numerical model that can be used as a design tool for structural elements having analogous geometrical and manufacturing characteristics. The numerical analysis, performed in the elastic regime with a standard finite element (FE) code, was strongly correlated with the laboratory determination of fibre-volume fractions and of some elastic parameters of the material system. Other parameters, like the shear modulus values G, were in fact appropriate…
Modal and Structural FEM Analysis of a 50 ft Pleasure Yacht
2012
In this paper a structural Finite Element analysis of a 50 ft pleasure vessel is presented. The study is performed under different loads conditions: modal analyses have been done in order to find the natural frequencies of the vessel, structural analyses to verify the strength of the vessel to design loads. The design loads for the vessel considered are computed according to RINA rules for the construction and classification of pleasure vessels [1]. Two different composites are used for the lamination: one is a monolithic sequence of short fibre and balanced glass lamina, used for the bottom of the vessel and for structural reinforcements, the other is a sandwich made of glass fibre composi…
BEM application on an external problem comparison with both theoretical and finite elements results and observations on divergence strip
1992
Abstract By means of a computer program the Boundary Element Method is applied to a central hole in an undefined plate with uniform load along the boundary. Results are compared with those obtained by Kirsch's theoretical solution and a previous analysis by the Finite Element Method. The calculus of percentage error shows the advantage of the Boundary Element Method on the external problem with regard to the Finite Element Method. The error causes near the boundary internal points are analysed with the existence of a strip, where the result is not reliable in evidence.
DESIGN OPTIMIZATION AND ANALYSIS OF A NEW REAR UNDERRUN PROTECTIVE DEVICE FOR TRUCK
2010
In this paper the optimization process of a new High Energy Absorption Rear Underrun Protective Device called HEARUPD is discussed. The main objectives of the HEARUPD design optimization process have been related to the reduction in car decelerations (high crashworthiness) and avoiding the car underrun (high structure stability). In the implemented optimization process, the crash between an economy car (GEO Metro) and the rear part of a truck has been simulated by numerical models. A linear function of the decelerations measured on the car has been used as objective to minimize, the main dimensional values of the rear underrun protective device, instead, have been chosen as design variables…
Modeling the electromechanical impedance technique for the assessment of dental implant stability
2015
We simulated the electromechanical impedance (EMI) technique to assess the stability of dental implants. The technique consists of bonding a piezoelectric transducer to the element to be monitored. When subjected to an electric field, the transducer induces structural excitations which, in turn, affect the transducer's electrical admittance. As the structural vibrations depend on the mechanical impedance of the element, the measurement of the transducer's admittance can be exploited to assess the element's health. In the study presented in this paper, we created a 3D finite element model to mimic a transducer bonded to the abutment of a dental implant placed in a host bone site. We simulate…