Comparison of dynamic behaviour of EMA-3 railgun under differently induced loadings/Elektromagnetines saudykles "EMA-3" skirtingu apkrovos rezimu itakos begio dinaminiam buviui palyginimas

Comparison of dynamic behaviour of EMA-3 railgun of the French-German Research institute of SaintLouis (ISL) under differently induced loadings is presented. Both magnetic pressure loads are generated by two current injections and lead to identical projectile velocities reaching up to 1200 m/s. The main difference between the loads lays in different locations of the injection points. FE simulation results presented in terms of deflections of the sliding rail surface illustrate, that loading differences result into different dynamic behaviours of the railgun. The breech-feed loading, where both injections are induced in the start position of the rail, leads to higher oscillation amplitudes of rail deflections. It was found, that the railgun structure is dynamically less sensitive to the distributed (DES) loading, induced in two different points. Lyginama Prancuzijos ir Vokietijos tyrimu instituto elektromagnetines saudykles "EMA-3" dinamika veikiant skirtingai indukuojamoms apkrovoms. Abi magnetinio slegio apkrovos sukeliamos dviem elektros sroves pliupsniais ir leidzia pasiekti iki 1200 m/s kulkos greiti. Esminis skirtumas tarp apkrovu atsiranda del skirtingu sroves tiekimo tasku. Modeliavimo baigtiniu elementu metodu rezultatai apibudinami slydimo plokstumos ilinkiais ir parodo skirtinga abieju apkrovu poveiki begio dinaminei elgsenai. Pirmoji apkrova, susidaranti tiekiant srove dviem pliupsniais begio pradzioje, sukelia salygiskai didesnes begio pavirsiaus ilinkiu svyravimu amplitudes. Skaiciavimais nustatyta, kad saudykle yra ne tokia jautri paskirstyto energijos tiekimo rezimui, kai apkrova indukuojama sroves pliupsniais dviejose skirtinguose begio vietose. [TEXT NOT REPRODUCIBLE IN ASCII.]