Search results for "progettazione"
showing 10 items of 581 documents
On relation between J-integral and heat energy dissipation at the crack tip in stainless steel specimens
2019
In this paper, an experimental procedure to evaluate the elastic-plastic J-integral at the tip of a fatigue crack is presented. According to this new approach, the elastic component of the J-integral is derived from Thermoelastic Stress Analysis, while the plastic component of the J-integral is derived from the heat energy loss. An analytical link is proposed to apply this new experimental technique. Therefore, the elastic-plastic J-integral range was evaluated starting from infrared temperature maps measured in situ during crack propagation tests of AISI 304L stainless steel specimens. It was found that the range of the infrared thermography-based J-integral correlated well the crack growt…
Ingegnerizzazione di una macchina prototipale per processi di saldatura linear friction welding
2012
Influence of the anisotropy of sisal fibers on the mechanical properties of high performance unidirectional biocomposite lamina and micromechanical m…
2021
Abstract High performance biocomposites reinforced by sisal fibers, are between the most promising materials that could be used in various fields, from automotive to civil constructions, thanks to their good mechanical performance, as well as to the low cost and the great availability of the fiber. Nevertheless, at present their practical use is prevented by the limited knowledge of their mechanical performance. The results of the present study have shown that the intimate fibrillar structure of the sisal fiber is associated with a high anisotropy involving not only the elastic parameters, but also the damage processes with typical fiber splitting phenomena, that influence noticeably the bi…
A quantitative investigation on the thermoelastic effect of CFRP laminates
2009
The thermoelastic effect on CFRP laminates with various lay-ups is investigated. A thick low crimp unidirectional fabric reinforcement is adopted. The measured thermoelastic signal is compared with predictions from two analytical models based on the meso-mechanical bulk properties of the lamina and on assuming a strain witness behaviour of the surface resin rich layer.
STUDIO DI UN’APPLICAZIONE IN CAMPO AERONAUTICO DI COMPOSITI STRUTTALI IBRIDI RESISTENTI AL FUOCO
2013
In the aeronautical/aerospace structural design the increasing demands of materials having high mechanical performance, has led to the a wide use of Polymeric Matrix Composites (PMCs) mainly reinforced by carbon fibers (Carbon Fiber Reinforced Plastics, CFRP). The main drawbacks in the use of such composites are due to high sensitivity to environmental features and low working temperatures; moreover, these materials do not tolerate the fire exposure because of the inflammability of both the matrix and the fibers. In order to develop a composite that combines the structural performance of CFRP with a good strength to high temperatures and fire, in the present work the use of a hybrid composi…
SISTEMI VERDI COME CULTURA RIGENERATIVA: STRUMENTI E TECNOLOGIE
2021
The study analyzes and proposes in the historical and in the area immediately to it adjacent, the "values-nature" of the buildings through the creation of gardens wall and vertical gardens in the elevatiloy of non-monumental buildings. The study deepens in particular the specificity of the garden roof and the garden vertical, recognizing benefits and critical issues that distinguish these green systems for construction. It also deepens the concept of resilience in close relationship sustainability and regenerative design applied to the built environment. The theme of regenerative design is studied and promoted as an adaptive strategy at the design stage; it requires you to leave nature stre…
SURFACE AND MECHANISTIC PROPERTIES OF RECYCLED BITUMINOUS MIXTURES
2019
EXECUTIVE SUMMARY Problem Often, when the characteristics of a bituminous mixture are analised, there are major differences between in-lab and in-situ results. This is due to the fact that the procedures and techniques implemented during the design phase (in lab) may be different from those used on site. Then, is very important to be able to predict the main properties of a mixture particularly when innovative materials are used. For example, when crumb rubber is used, phisical and volumetric properties of mixes may change over time, in particular due to the swelling phenomenon that it alters different properties of the mixture (e.g., viscosity). This study aims to investigate the main aspe…
Preliminary design of a magnetorheological brake for automotive use
2011
After an initial study of the characteristics of magnetorheological fluids based on a thorough search in literature, a preliminary configuration of MR brake is proposed. It comes from the evaluation of the main factors influencing the design of an appropriate magnetic circuit, and then the performance obtained in terms of brake torque. The analytical study of the brake has allowed a first preliminary sizing. Through the subsequent execution of an electromagnetic finite element model, created in ANSYS, it was possible to assess more accurately the distribution of the magnetic field inside the MR fluid and hence the resistance to relative motion between rotor and stator. The work needs an acc…
Haemodynamic predictors of a penetrating atherosclerotic ulcer rupture using fluid-structure interaction analysis
2013
We present preliminary data on the flow-induced haemodynamic and structural loads exerted on a penetrating atherosclerotic aortic ulcer (PAU). Specifically, one-way fluid-structure interaction analysis was performed on the aortic model reconstructed from a 66-year-old male patient with a PAU that evolved into an intramural haematoma and rupture of the thoracic aorta. The results show that elevated blood pressure (117 mmHg) and low flow velocity at the aortic wall (0.15 m/s(2)) occurred in the region of the PAU. We also found a low value of time-averaged wall shear stress (1.24 N/m(2)) and a high value of the temporal oscillation in the wall shear stress (oscillatory shear index = 0.13) in t…