Search results for "Finite element"
showing 10 items of 892 documents
Central Bursting Defects in Drawing and Extrusion: Numerical and Ultrasonic Evaluation
1993
Abstract A new approach for the prediction of central bursting defects in extrusion and drawing is proposed: a finite element analysis of the processes has been carried out, and the obtained results have been elaborated by means of a post-processor, which, employing a proper ductile fracture criterion, is able to suggest if and where the central burst occur. An ultrasonic control system able to detect the insurgence of defects with a resolution of 0.2 mm. has been setup in order to verify the predictive capability of the model. The experimental results show a good agreement with the numerical predictions confirming the effectiveness of the proposed approach, whose industrial application app…
Measuring of Geometrical Precision of Some parts Obtained by Asymmetric Incremental Forming Process After Trimming
2007
Asymmetric Incremental Forming exalts the advantages of Incremental Forming process since no dies are strictly necessary. In this way complex geometries may be manufactured with a very simple clamping equipment. On the other hand, this characteristic determines some intrinsic drawbacks which penalise its industrial suitability; first of all, the dimensional control of the manufactured part is a still open point for researchers all over the world. Several approaches have been already proposed in the last years to solve the problem, resulting only in partial solutions. At the same time, up to now, the numerical simulation did not supply significant aid to the designers, due to the problem com…
DEPENDENCE OF MACHINING SIMULATION EFFECTIVENESS ON MATERIAL AND FRICTION MODELLING
2008
Numerical simulation of cutting processes is still a very difficult matter, although some relevant geometrical simplifications and high-performance codes are used. A large number of technical papers have been focused on the predictive capability of the codes: nevertheless the prediction quality is not very satisfactory if the problem is analyzed in a wide sense. In this paper the simple orthogonal cutting process of a plain-carbon steel is investigated taking into account different process conditions (cutting speed and feed rate). Furthermore, four material constitutive equations and three friction models were implemented and a sensitivity analysis was carried out comparing the numerical pr…
A Method for Reduction of Cogging Torque in PM Machines Using Stepped Magnets
2006
The paper presents a general approach to minimization of the cogging torque in electrical machines using surface-mounted magnets with discrete skew angle. Two types of pole shapes, namely monotonic skewing as well as herringbone-shaped magnets are proposed for the purpose of reducing the cogging torque. The elaborated algorithm is validated against the 3D finite element model as well as experimental data obtained from physical model of the motor. The presented cost-effective method leads to a great reduction of cogging torque with only slight decrease of overall electromagnetic torque.
Determination of temperature distribution in the cutting zone using hybrid analytical-FEM technique
2006
Abstract In this study, the temperature distribution in the cutting zone was determined by integrating thermal analytical and simulation models of orthogonal cutting process with uncoated and coated carbide tools. Primarily, 2D FEM simulations were run to provide numerical solutions of temperatures occurring at different points through the chip/tool contact region and the coating/substrate boundary under defined cutting conditions. In addition, an analytical model for heat transfer in the cutting tool and its partitioning, proposed in References [W. Grzesik, P. Nieslony, Physics based modelling of interface temperatures in machining with multilayer coated tools at moderate cutting speeds, I…
Experimental Investigation for Degradation Analysis of an RC Italian Viaduct and Retrofitting Design
2020
AbstractThe degradation state of RC bridge structures is one of the most important and difficult aspects to be interpreted. For these structures, structural analysis using FEM requires a reliable d...
Design and optimization of bonded patch repairs of laminated composite structures
2015
International audience; The present study proposes a method for design optimization of external patched repairs. The tensile behavior of notched specimens with patched repair was studied using finite element analysis and compared with experimental results. It was found that high stress concentrations along the transverse edges of circular patches and/or at the longitudinal edges of the hole leads to early damage initiation in the parent plate. The damage initiation site and its propagation depend on the patch in-plane stiffness. The optimal patch design can be characterized by a strength ratio R*. The overall design of the patch repair can be considered using a dimensionless design paramete…
Analytical evaluation of steel–concrete composite trussed beam shear capacity
2015
A calculation method for the prediction of the shear resistance of precast composite beams, named Hybrid Steel Trussed-Concrete Beams (HSTCBs), is herein proposed. HSTCBs are constituted by a prefabricated steel truss embedded within a concrete matrix cast in situ so that, after curing, the two materials work together in the mechanical response of the composite structural element, the steel truss behaving as reinforcement of the beam. The proposed analytical model is developed on the basis of the results of a reference experimental campaign of three-point bending tests available in the literature, carried out on specimens of HSTCB designed in order to attain a shear failure. Furthermore, th…
Braking procedure analysis of a pegs-wing ventilated disk brake rotor
2006
Fade test results of a ventilated disk brake rotor with pegs-wing performed by means of an inertia dynamometer, consisting of 14 repeated brake applications from an initial brake speed of 160 km/h down to 0 km/h, with constant deceleration are shown. The first brake application test results are compared to the FEM numerical predictions with MSC Visual Nastran on the entire disk. These conform well to the experimental data, although numerical thermal field is slightly higher than the experimental one. Besides, ventilated disk brake rotor shows great dimensional stability and the ability to dissipate a great amount of thermal flow.
Numerical and experimental analysis of load capacity of pressure vessels for large deformations
1991
Abstract A method of theoretical and experimental investigations of large deformations and load capacity of pressure vessels has been proposed. Algorithms and programs for numerical analysis (with the finite element method) of spatial stress and strain state and load capacity have been worked out according to the Prandtl-Reuss theory of plastic flow. Loading in the vessel was realized in an incremental way. The loading process was continued up to the moment when the maximum loading was obtained (i.e. the moment when state of equilibrium of the vessel was not possible). It has been found that in thin-walled circular vessels with rigid bottoms, when a ratio of length to their diameter is less…