In aircraft engines the blade resonant vibration amplitude is normally reduced by increasing structural damping using, for example, tip shrouds. These devices dissipate energy generated at contact surfaces between relative motion and friction force. Contact parameters, principally coefficient stiffness, are required to characterize dynamics of shrouded system. Moreover, if these severe wear occurs, a loss interference takes place dissipated shroud decreases. Consequently increases...

A superalloy traditionally offers excellent mechanical strength, resistance to thermal creep deformation, good surface stability and corrosion or oxidation. However, a often also needs performance in terms of fretting resistance. Experimental results regarding wear contact properties the René 80 are illustrated discussed. The widespread applications superalloys jointing with friction as turbine blade, is main motivation for characterizing their behaviour. experiments were performed at 100 Hz...

Slots in the disk of aircraft turbines restrain centrifugal load blades. Contact surfaces between blade root and slot undergo high contact pressure relative displacement that is typical condition which fretting occurs. The level ranges from zero to maximum during take-off. This cycle repeated for each mission. In this paper, a fatigue analysis additively manufactured blades presented. Blades are made an intermetallic alloy γTiAl. Fretting experiments were performed at frequency 0.5 Hz...

Results of X-ray residual stress measurements on Inconel 718 turbine shaft samples are here proposed. The paper presents part the EU STREP project VERDI activity, where aim was to supply those who numerically simulate machining process with an experimental database proved reliability. Measurements were planned a set machined different levels cutting speed and feed rate. Due attention given assessment uncertainty results. A surface values depth profiles is presented estimated both values. be...

In aircraft engine the blade resonant vibration amplitude is reduced by increasing structural damping using, for example, tip shrouds. These devices dissipate energy generated at contact surfaces between relative motion and friction force. Contact parameters as coefficient stiffness are required to characterize dynamics of shrouded systems. Moreover if severe wear occurs a loss interference takes place, shroud not longer able catastrophic failure could take place. A test rig measurement...

Fretting wear is a complex phenomenon that occurs at component interfaces undergo low amplitude oscillation under high contact pressure. The aim of this paper to investigate the fretting behavior both with experiments and numerical code. hysteresis cycles have been measured through experiment and, end test, worn volume has determined. A code developed predict volume. three-dimensional elastic problem solved by using semi-analytical half space model. uses law for which proportional dissipated...

A library of poly(ether urethane)-based supramolecular hydrogels was designed, showing quick gelation, no phase separation, remarkable mechanical and self-healing properties.

Abstract The term “Foreign Object Damage (FOD)” refers to the damage associated with impact of particles on aircraft engine components that causes changes in fatigue strength as a result induced stress concentrations, residual stresses and microstructural changes. This paper presents Finite Element (FE) models created study field by impacts steel sphere 7075-T6 hourglass specimen. occur at minimum cross section, normal oblique directions. results reveal event an axial tensile are greater...

Residual stress state in turbine disk after machining could affect the life of disk. For this reason, a strong effort is made today to predict residual distribution by modelling process. However, it should be stressed that numerical models need reliable and trusty experimental data validated calibrated. This work focused on detection produced milling Inconel 718, aim supply an database for validation. The stresses were detected means X-ray diffraction technique. robustness adopted...

Results of residual stress measurements on Inconel 718 turbine components after machining are here presented. The work is focused the experimental detection state produced turning (orthogonal cutting and standard) milling. aim activity was to supply an data base proved reliability for milling model validation. This performed inside EU STREP project VERDI. stresses were detected by means X-ray diffraction technique. plan worked with different working parameters (cutting velocity feed rate)...

The modelling of the friction interfaces has received much attention in recent years from aerospace industry. In order to obtain reliable prediction nonlinear dynamic behaviour disc and blades engine forces at interfaces, such as under-platform dampers, blade fir tree roots or shrouds, must be modelled accurately. Two contact parameters, namely stiffness coefficient friction, are sufficient model, with good accuracy, contact. parameters obtained experimentally, interest for designer only if...

Physical and chemical hydrogels are promising platforms for tissue engineering/regenerative medicine (TERM). In particular, physical suitable use in the design of drug delivery systems owing to their reversibility responsiveness applied stimuli external environment. Alternatively, represents a better strategy produce stable 3D constructs TERM field. this work, these two strategies were combined develop multi-functional formulations integrating both potential approaches single device....