REFLECT – Research flight of EURADOS and CRREAT: Intercomparison of various radiation dosimeters onboard aircraft

Aircraft crew are one of the groups of radiation workers which receive the highest annual exposure to ionizing radiation. Validation of computer codes used routinely for calculation of the exposure due to cosmic radiation and the observation of nonpredictable changes in the level of the exposure due to solar energetic particles, requires continuous measurements onboard aircraft. Appropriate calibration of suitable instruments is crucial, however, for the very complex atmospheric radiation field there is no single reference field covering all particles and energies involved. Further intercomparisons of measurements of different instruments under real flight conditions are therefore indispensable. In November 2017, the REFLECT (REsearch FLight of EURADOS and CRREAT) was carried out. With a payload comprising more than 20 different instruments, REFLECT represents the largest campaign of this type ever performed. The instruments flown included those already proven for routine dosimetry onboard aircraft such as the Liulin Si-diode spectrometer and tissue equivalent proportional counters, as well as newly developed detectors and instruments with the potential to be used for onboard aircraft measurements in the future. This flight enabled acquisition of dosimetric data under well-defined conditions onboard aircraft and comparison of new instruments with those routinely used. As expected, dosimeters routinely used for onboard aircraft dosimetry and for verification of calculated doses such as a tissue equivalent proportional counter or a silicon detector device like Liulin agreed reasonable with each other as well as with model calculations. Conventional neutron rem counters underestimated neutron ambient dose equivalent, while extended-range neutron rem counters provided results comparable to routinely used instruments. Although the responses of some instruments, not primarily intended for the use in a very complex mixed radiation field such as onboard aircraft, were as somehow expected to be different, the verification of their suitability was one of the objectives of the REFLECT. This campaign comprised a single short flight. For further testing of instruments, additional flights as well as comparison at appropriate reference fields are envisaged. The REFLECT provided valuable experience and feedback for validation of calculated aviation doses

Advanced metal sheet testing tool - Bulge test

V rámci této práce bylo cílem rozšíření platnosti křivky zpevnění oceli DP1000. Zkoušky byly provedeny ve spolupráci s firmou COMTES FHT a.s. Základní diagram závislosti napětí a deformace byl určen za pomoci jednoosé tahové zkoušky. Tento diagram byl dále prodloužen pomocí dat z bulge testu provedeného dle normy ČSN EN ISO 16808. Druhým hlavním cílem této práce pak bylo porovnání experimentálních dat z bulge testu a výsledků numerických simulací. Pro numerické simulace byl vytvořen MKP model s předpokladem izotropie materiálu. Při průběhu zkoušek byly napětí a deformace vyhodnocovány za využití optického systému. Dále byly také provedeny konstrukční úpravy měřeného tlaku a siloměru.ObhájenoThe aim of this bachelor thesis was to extend the validity of DP1000 steel hardening curve. The tests were performed in cooperation with COMTES FHT a.s. company. The basic stress and strain dependence diagram was defined using a uniaxial tensile test. This diagram was further extended with the use of data from the bulge test carried out according to the ČSN EN ISO 16808 standard. The other objective of the thesis was the comparison of experimental data from the bulge test and the results of numerical simulations.An FEM model was created with the assumption of material isotropy for numerical simulations. During the tests, stress and strain were evaluated using an optical system. Furthermore, structural modifications of the measured pressure and force gauge were also carried out

Advanced metal sheet testing tool - Bulge test

V rámci této práce bylo cílem rozšíření platnosti křivky zpevnění oceli DP1000. Zkoušky byly provedeny ve spolupráci s firmou COMTES FHT a.s. Základní diagram závislosti napětí a deformace byl určen za pomoci jednoosé tahové zkoušky. Tento diagram byl dále prodloužen pomocí dat z bulge testu provedeného dle normy ČSN EN ISO 16808. Druhým hlavním cílem této práce pak bylo porovnání experimentálních dat z bulge testu a výsledků numerických simulací. Pro numerické simulace byl vytvořen MKP model s předpokladem izotropie materiálu. Při průběhu zkoušek byly napětí a deformace vyhodnocovány za využití optického systému. Dále byly také provedeny konstrukční úpravy měřeného tlaku a siloměru.ObhájenoThe aim of this bachelor thesis was to extend the validity of DP1000 steel hardening curve. The tests were performed in cooperation with COMTES FHT a.s. company. The basic stress and strain dependence diagram was defined using a uniaxial tensile test. This diagram was further extended with the use of data from the bulge test carried out according to the ČSN EN ISO 16808 standard. The other objective of the thesis was the comparison of experimental data from the bulge test and the results of numerical simulations.An FEM model was created with the assumption of material isotropy for numerical simulations. During the tests, stress and strain were evaluated using an optical system. Furthermore, structural modifications of the measured pressure and force gauge were also carried out