Search results for "T method"
showing 10 items of 1254 documents
On the material flow in fsw of T-joints: influence of geometrical and tecnological parameters
2008
Friction stir welding (FSW) now definitively reached a large interest in the scientific community and what is more in the industrial environment, due to the advantages of such solid state welding process with respect to the classic ones. The latter aspects are relevant also with reference to joints characterized by a complex geometry. What is more, advanced FEM tools permit to develop effective engineering of the processes; quantitative results can be acquired from numerical simulations once basic information, as the process mechanics and the material flow, are certain. Material flow plays a fundamental role in FSW since it determines the effectiveness of the joints or, in turn, the insurge…
On the dynamic behavior of piezoelectric active repair by the boundary element method
2011
The dynamic behavior of piezoelectric active repair bonded on cracked structures is analyzed in this article. The boundary element code used to perform the simulations is implemented in the framework of piezoelectricity in order to model the coupling between the elastic and the electric fields, which represents the most important feature of piezoelectric media. The fracture mechanics problem, i.e. the crack, as well as the bonding layer between the host structure and the active patch is modeled by means of the multidomain technique provided with an interface spring model. More particularly, the spring interface model allows considering the bonding layer as a zero-thickness elastic ply char…
Numerical and experimental verification of new method for connecting pipe to flange by cold forming
2015
Abstract In this paper a new method of connecting pipe to flange without welding is presented. This method is a cold forming process that is based on plastic expansion/deformation of the pipe into a modified standard flange by use of a cold forming tool. The method is patented by Quickflange Technology AS and represents a highly feasible alternative to welding. The successful use of the method requires the ability to predict dimensional and stress/strain characteristics of the pipe and flange after the connection process in order to evaluate the connectivity to the adjacent flange as well as the leak tightness. In addition the ability to predict the process force during the connection proce…
The evaluation of springback in 3D stamping and coining processes
1998
Abstract An effective predictive technique of the elastic springback in a fully 3D 90° V-punch V-die bending process is presented. This is based on a combined approach in which an explicit finite element code was used to simulate the loading phase of the process whilst an implicit procedure was used to analyse the springback phase. Two different punches with a nose radius of 4 and 8 mm were used. An increase in the springback ratio with the coining load was observed with the lower nose radius. Conversely, an increase in the springback ratio with the coining load up to a peak value (>1), corresponding to a force of about 20 kN, followed by a decrease in the springback ratio with increasing t…
Stability analysis of clay brick masonry columns: numerical aspects and modelling strategies
2014
Stability analysis of masonry piers and columns is one of the most frequently treated subjects in the field of structural engineering. This attention is probably due to the challenge to solving the problem including different effects, which play an important role in evaluating the response of eccentrically-loaded columns. In this connection, accurate stability analysis of masonry piers and columns has to take into account the non-linear stress–strain law of masonry in compression, the limited tensile strength, the induced slenderness due to crack formation and geometrical non-linearity. Different theoretical models and numerical approaches were developed in the past to analyze the combined …
Cogging torque comparison of Interior Permanent Magnet Synchronous Generators with different stator windings
2017
This paper presents the comparison between the cogging torques produced by four IPMSGs (Interior Permanent Magnet Synchronous Generators) with different stator winding configurations. More in detail, an IPMSG model, which is derived from a commercial geometry, is analyzed through means of a FEM (Finite Element Method) approach. Then, three more structures are determined and analyzed by adequately changing the number of stator slots of the basic IPMSG stator structure and by maintaining the same rotor configuration. From the obtained simulation results, the cogging torque components for each structure are determined and compared. From this comparison, it can be stated that the use of dissymm…
Buckling and Postbuckling of Stiffened Composite Panels with Cracks and Delaminations by Ritz Approach
2017
A Ritz approach for the analysis of buckling and post-buckling of stiffened composite panels with through-the-thickness cracks and/or delaminations is presented. The structure is modeled as the assembly of plate elements whose behavior is described by the First-order Shear Deformation Theory and von Karman’s geometric nonlinearities. Penalty techniques ensure continuity along the edges of contiguous plate elements and the enforcement of the restraints on the external boundaries. They are also used to avoid interpenetration problems. General symmetric and unsymmetric stacking sequences are considered. A computer code has been developed and used to validate the proposed method, comparing the …
Finite Element Method Analysis of a Spur Gear with a Corrected Profile
2007
The difference between the stress value calculated by a two-dimensional finite element model of spur gears and those obtained by the rules in ISO 6336 was evaluated. Hertz theory, which provides information on the extension of the contact area and the maximum value of the contact pressure, was used to choose the dimensions of the elements. The mesh was created using the stress analytical solution relative to a model consisting of two cylinders in contact. Analogous optimization was executed for the mesh of the teeth feet; a mesh of 15 elements was considered optimum, because it minimized the difference to 0.5 per cent in the bending stress calculation. Stress values, obtained using the fin…
COMPARATIVE ANALYSIS OF RIGID AND FLEXIBLE STRUCTURES OF THE ECCENTRIC PRESSES
2007
Abstract The aim of this paper is to make a comparative study of the static behaviour of the eccentric presses, using the finite elements method, on the rigid structure and on the flexible structure, respectively. The finite elements modelling of the component elements of the presses are done in two ways: node by node link type (rigid structure) or using a linking element spring damper type (flexible structure). On these two structures there is successively applied a number of static analyses, in order to determine the strain of working area and the design of the stiffness graph.
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…