0000000000173544
AUTHOR
G Virzì Mariotti
showing 7 related works from this author
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…
Effect of Cold Working and Ring Indentation on Fatigue Life of Aluminum Alloy Specimens
2013
The article deals with the fatigue life of plates with hole made of aluminum alloy. Specifically, the combined effect of cold working expansion and ring indentation on improved fatigue life performance was investigated. Multiple fatigue tests were performed to determine the cycles to failure and the corresponding W¨ ohler diagram. Experimental results were compared with those of nontreated specimens. The conclusion was that cold working expansion and indentation create a delay on crack formation and fatigue failure.
Optimization of the characteristic angles of both front and rear McPherson suspensions on a circular track using multi-body numerical simulation
2009
The research reported in this paper aims to simulate the road-holding of a virtual vehicle using multi-body simulation to estimate both the contact forces between the tyre and ground and the roll motion when cornering. Furthermore, the effect of the characteristic angles on the variation in the forces of the tyre in contact with the ground is studied to determine optimal values for these angles. Emphasis is placed on an average-class vehicle, of which both the external dimensions and mass are chosen appropriately, with a McPherson suspension mounted on both the front and the rear. The characteristic values of the camber and toe-in angles, in both the front and the rear, are optimized for m…
Performances Comparison for a Rotating Shaft Suspended by 4-Axis Radial Active Magnetic Bearings via 𝜇 -Synthesis, Loop-Shaping Design, and Sub ( 𝐻…
2011
The control systems applied on active magnetic bearing are several. A perfect levitation is characterized by maintaining the operating point condition that is characterized by the center of stator coincident with the geometric center of shaft. The first controller implemented for this purpose is PID controller that is characterized by an algorithm that leads the amplifier to produce control current until the operating point condition is not reached, this is obtained by an integration operator. The effect of an integrator is essential but not necessary for a centered levitation for example in the robust control characterized by a dynamic model depended on plant of system so that it depends o…
Experimental analysis of the contact pressure distribution in an off-road tyre
2009
In this paper the results of experimental tests are shown, lead by extended method of measurement, on a tire for an off-road vehicle 175/82 R16, inserting Prescale paper at the contact with the ground. The experimental analysis of the pressures is lead, in cross-sectional direction, in 5 zones correspondents to the middle of the single dowels constituting the tread. The results are analyzed by means of software predisposed to the scope so as to go back easily to the value of the pressure. The obtained results are critically analyzed and the result are compared with those obtained by the formulas of Rowland and MacLaurin, and by the nominal pressure at ground, concluding that the expression …
Design and use of a Fatigue Test Machine in Plane Bending for Composite Specimens and Bonded Joints
2011
Polymeric and composites materials are increasingly used in industry as structural parts, so that specific information on their mechanical properties "at long term" (creep, relaxation, fatigue) are requested. The design and implementation of these components also requires that they are permanently connected together to perform certain functions. The use of adhesives in structural joints has increased over recent years thanks to the continuous development by companies which provide the market with adhesive having better and better mechanical properties. The main areas relate to the aerospace, aeronautical and automotive industries, where requirements are required for lightness and reliabilit…
A New Theoretical Approach on Teenage Cyclist-Vehicle Crash
2016
Data obtained in teenage cyclist impact against three vehicles (sedan, SUV and Pick Up), tested in previous works, are analyzed to verify the theoretical results by the coupling of momentum conservation principle and energy conservation principle. The speed of vehicle and thorax are compared with theoretical ones, obtaining an excellent agreement. Following the results found in the literature, particular emphasis is done on teenager cyclist thorax and head speeds, indicating that the cyclist speed can be theoretically until 1,41 times the impact speed, while greater values, until 2, are obtained in the simulations. A small slowing of the vehicle is found theoretically and in the simulations…