Search results for "thermo-mechanic"
showing 10 items of 49 documents
Analysis of the thermo-mechanical behaviour of the DEMO Water-Cooled Lithium Lead breeding blanket module under normal operation steady state conditi…
2015
Within the framework of DEMO R&D activities, a research cooperation has been launched between ENEA, the University of Palermo and CEA to investigate the thermo-mechanical behaviour of the outboard equatorial module of the DEMO1 Water-Cooled Lithium Lead (WCLL) blanket under normal operation steady state scenario. The research campaign has been carried out following a theoretical-computational approach based on the Finite Element Method (FEM) and adopting a qualified commercial FEM code. In particular, two different 3D FEM models (Model 1 and Model 2), reproducing respectively the central and the lateral poloidal-radial slices of the WCLL blanket module, have been set up. A particular attent…
Beta forging of Ti-6Al-4V: Microstructure evolution and mechanical properties
2013
Titanium alloys are finding an increasing use in the aeronautical field, due to their characteristics of high mechanical properties, lightness and corrosion resistance. Moreover these alloys are compatible with the carbon fibre reinforced plastics that are also finding a wide use in the aeronautical field. On the other hand the use of these alloys implies some drawbacks, for example titanium alloys are often considered more difficult to form and generally have less predictable forming characteristics than other metallic alloys such as steel and aluminum. In this paper was studied both the microstructure evolution and the mechanical properties of a Ti-6Al-4V rolled bar after hot forging. The…
Thermal optimization of the Helium-Cooled Lithium Lead breeding zone layout design regarding TBR enhancement
2017
Abstract Within the framework of EUROfusion R&D activities, CEA-Saclay has carried out an investigation of the thermal and mechanical performances of alternative designs intended to enhance the Tritium Breeding Ratio (TBR) of the Helium-Cooled Lithium Lead (HCLL) Breeding Blanket (BB) for DEMO. Neutronic calculations performed on the 2014 DEMO HCLL baseline predicted a value of TBR equal to 1.07, lower than the required value of 1.1, necessary to ensure the tritium self-sufficiency of the breeding blanket taking into account uncertainties. In order to reach the TBR target, the strategy of the steel amount reduction inside the HCLL module breeding zone (BZ) has been followed by suppressing s…
On the effect of stiffening plates configuration on the DEMO Water Cooled Lithium Lead Breeding Blanket module thermo-mechanical behaviour
2019
Abstract Within the framework of the pre-conceptual design of the EU-DEMO Breeding Blanket (BB) supported by EUROfusion action, results of the research activities carried out in the last years have highlighted that changes in the proposed Water Cooled Lithium Lead (WCLL) BB design have to be considered, especially as to the liquid breeder circulation path within the BB module. Therefore, in view of the definition of a final WCLL BB module layout, a parametric campaign of numerical analyses has been carried out at the University of Palermo in order to assess the impact of different SPs configurations on the module thermo-mechanical performances. To this purpose, attention has been focussed o…
Modelling of the thermal mechanical behaviour of a single size beryllium pebble bed
2001
The Helium Cooled Pebble Bed (HCPB) Blanket for fusion power reactors and the ITER breeding blanket are based on the use of pebble beds of lithium ceramics as breeder and beryllium as neutron multiplier. Experimental activities were performed at Forschungszentrum Karlsruhe concerning the measurement of pebble bed heat transfer parameters. At the Department of Nuclear Engineering of the University of Palermo, the experimental results have been reproduced by means of the ABAQUS finite element code. Moreover, a thermal-mechanical theoretical model has been developed for single size beryllium pebble beds. In the paper the results from the numerical and theoretical analyses and the comparison wi…
Material valorisation of amorphous polylactide. Influence of thermo-mechanical degradation on the morphology, segmental dynamics, thermal and mechani…
2012
[EN] This paper reports the effects of multiple mechanical recycling on the structure and properties of amorphous polylactide (PLA). The influence of the thermo-mechanical degradation induced by means of five successive injection cycles was initially addressed in terms of macroscopic mechanical properties and surface modification. A deeper inspection on the structure and morphology of PLA was associated to the thermal properties and viscoelastic behaviour. Although FT-IR analysis did not show significant changes in functional groups, a remarkable reduction in molar mass was found by viscometry. PLA remained amorphous throughout the reprocessing cycles, but the occurrence of a cold-crystalli…
Effect of processing temperature and mixing time on the properties of PP/GnP nanocomposites
2020
Abstract During processing of molten polymers the thermal and mechanical stress acting on the melt in presence of oxygen can induce degradation with a modification of the chemical structure of the polymers. This picture can become even more relevant if the melt is a multiphasic polymer system. In this last case, the effects of the degradation depend also on the presence of a second phase and on the interactions between the two phases. In this work, the effect of the processing conditions, temperature and time, have been considered in order to investigate the thermo-mechanical and thermo-oxidative degradation of nanocomposites made by polypropylene and different contents of graphene nanoplat…
Dielectric Spectroscopy of Recycled Polylactide
2014
The effects of multiple mechanical recycling on amorphous polylactide (PLA) were simulated by means of five successive injection-grinding cycles. The influence of the induced thermo-mechanical degradation on the dielectric properties of PLA was analysed. The relaxation spectra were studied in terms of the complex dielectric permittivity (ε0 and ε00) and the dielectric loss tangent, tg(d) in the frequency range from 102 to 107 Hz over the temperature interval from 0 C to 140 C. It was possible to distinguish two relaxations zones, one at low temperatures and high frequencies (b relaxation) and another at higher temperatures and lower frequencies (a relaxation). The individual relaxations wer…
Thermo-mechanical analyses and ways of optimization of the helium cooled DEMO First Wall under RCC-MRx rules
2017
Abstract The EUROfusion Consortium develops a design of a fusion power demonstrator plant (DEMO) in the framework of the European “Horizon 2020” innovation and research program. One of the key components in the fusion reactor is the Breeding Blanket (BB) surrounding the plasma, ensuring tritium self-sufficiency, heat removal for conversion into electricity, and neutron shielding. Among the 4 candidates for the DEMO BB, 2 of them use helium as coolant (HCPB, HCLL), and another one (DCLL) uses helium to cool down the First Wall (FW) only. Due to uncertainties regarding the plasma Heat Flux (HF) load the DEMO BB integrated FW will have to cope with, a set of sensitive thermal and stress analys…
Experimental tests and thermo-mechanical analyses on the HEXCALIBER mock-up
2008
Abstract Within the framework of the R&D activities promoted by European Fusion Development Agreement on the helium-cooled pebble bed test blanket module to be irradiated in ITER, ENEA Brasimone and the Department of Nuclear Engineering of the University of Palermo performed intense research activities on the modelling of the thermo-mechanical behaviour of both beryllium and lithiated ceramics pebble beds, which are envisaged to be used, respectively, as neutron multiplier and tritium breeder. In particular, at the DIN a thermo mechanical constitutive model was developed for both lithiated ceramics and beryllium pebble beds and it was successfully implemented on a commercial finite element …