On the Behavior of Longitudinal Strain of a Buried Pipe Subjected to Ground Spread Caused by Liquefaction Observed in Centrifuge Model Tests

The behavior of longitudinal strain of buried pipes subjected to ground spread was investigated by scale model tests using a large centrifuge test facility. The longitudinal strain of buried pipes subjected to longitudinal ground spread is found to be generated by the energy of movement but not the displacement of the spreading soil. First, the remarkable strain appears at the initial transient phase of the spread, reaches its maximum and finally decays during the time the displacement of the spread proceeds. Next, it can be indicated that the induced pipe strains may have linear relationships with the square of velocities of the spread. When the roughness of the pipe is higher the maximum strain becomes larger and the duration time of large strain phase seems to become longer

Effective Stress Analysis by Shear Strain Controllable Model and its Application to Centrifuge Shaking Model Test

Effective stress FEM which is able to control the growth of shear strains is proposed. Its validity is firstly confirmed through the simulation of undrained cyclic torsional shear tests. Then, it is applied to simulation of centrifuge shaking model tests; the experimental model consists of a caisson type quay wall and reclamation laid on the sand layer. Development of shear strain is shown to be controlled arbitrary keeping the excess porewater pressure generation unchanged through the simulation of undrained cyclic torsional shear test, which indicates that proposed model can be applicable to variety of soils with different density and fines contents. Displacement is shown to be controlled keeping excess porewater pressure generation constant in the centrifugal model, too, and good agreement is obtained between test and analysis by controlling the parameter for shear strain development

Configurational evidence for antiferromagnetic interaction in disordered magnetic ionic liquids by X-ray scattering-aided hybrid reverse Monte Carlo simulation

Published online: 11 May 2020Magnetic ionic liquids (MIL) are a new type of ionic liquids that show paramagnetic response to magnetic fields. Here, we elucidate a plausible 3D liquid structure of the 1-ethyl-3-methyl-imidazolium tetrachloroferate (Emim[FeCl4]) and 1-butyl-3-methyl-imidazolium tetrachloroferate (Bmim[FeCl4]) MILs by X-ray scattering-aided hybrid reverse Monte Carlo simulations. Bmim[FeCl4] showed anomalously continuous structural changes over a wide temperature range (90–523 K) without crystallization, while Emim[FeCl4] displayed a melting point at 291 K with no glass transition.Conventional electron radial distribution function (ERDF) analysis provides misleading information about the structures of these MILs due to the mutual cancelation of the partial anion-anion and anion-cation ERDFs. Subsequent hybrid reverse Monte Carlo (HRMC) analysis revealed the precise coordination structures of both ionic liquids, and the alternating periodic arrangement of the anions and cations was visualized based on the HRMC simulation results. The results clearly revealed that the 1st coordination structure of the FeCl4 anion around the Bmim cation was widespread compared to that of the Emim cation, resulting in the absence of crystallization. In addition, we obtained new insights into the antiferromagnetic interaction between the FeCl4− ions of Bmim[FeCl4] even in the absence of the crystallization at low temperatures. Our results shed new light on the development of MILs not only for practical applications but also for the advancing the basic science of pure liquids with a high magnetic response.ArticleJournal of Molecular Liquids.311(1):113321(2020)journal articl

Minimum Quench Energy Evaluation of ITER Toroidal Field Conductor Using an Inductive

To keep a stable operation of the ITER Toroidal Field (TF) coil without quenching, it is necessary to know the threshold of allowable external heating energy, which is called minimum quench energy (MQE), of the TF conductor during the operation in ITER. To evaluate the MQE, a series of conductor heating tests has been performed during the TF Insert (TFI) test campaign. TFI is a single layer about 9-turn solenoid wound from ITER TF conductor. The coil diameter is 1.44 m and the conductor length is around 40 m. TFI is force-cooled by supercritical helium inside the TF conductor. For the TFI, 68 kA current had been applied under 10.8 T background field as rated operation condition. During its operation, the conductor was inductively heated by an inductive heating coil. Through the test, MQE of the TFI has been obtained