Experimental and numerical analyses on LiSO4 and Li2TiO3 pebble beds used in a ITER test blanket module

Mechanical characterization of Li2TiO3 and Li4SiO4 pebble beds: Experimental determination of the material properties and of the pebble bed effective values

“…We can point out that in the tests in which the loading remained under the rupture strength, the surface of the pebbles did not show cracks near the contact zone. Differently in the oedometric tests for correspondent values of the load, a lot of cracks were detected near the contact zone [6], probably caused by the radial constraints. Fig.…”

“…• for Li 2 TiO 3 : K MT = 331 N/mm • for Li 4 SiO 4 : K OS = 238 N/mm Transforming the load-displacement curve in strainstress curve with reference to the maximum axial crosssection, we found an effective modulus in the unloading phase: For a given material, the effective modulus of the spheres and that obtained in oedometric tests on pebble bed are almost equal [6].…”

“…This paper deals with the experimental activity performed at the Dipartimento di Ingegneria Meccanica Nucleare e della Produzione of the University of Pisa (Italy) in order to determine the effective properties of the pebble beds and to develop a constitutive model. Oedometric and uniaxial conductivity tests on pebble bed are illustrated elsewhere [5,6]. This paper reports the results of two mechanical characterization tests on lithium metatitanate (Li 2 TiO 3 ) and lithium orthosilicate (Li 4 SiO 4 ) spheres.…”

Thermal transient and the temperature profile in a HELICA mock-up simulated by a new finite element homogenous model

“…The stress-strain curve of pebble beds, during a compression loading, depends on the plastic deformation in correspondence of the contact between pebbles [1]. Eq.…”

“…http://dx.doi.org/10.1016/j.fusengdes.2013.04.026 on ceramic pebble beds (lithium ortosilicate and lithium metatitanate). In particular, the effective thermal conductivity of the beds, versus the temperature and the axial pressure, has been determined by means of an experimental set up purposely designed [1]. The experimental tests have been simulated with the FEM codes using a homogenous model for the pebble bed.…”