TY JOUR TI MULTIGRID FINITE ELEMENT METHOD IN THE CALCULATIONS OF THREE-DIMENSIONAL COMPOSITE PLATES AND BEAMS OF IRREGULAR FORM KW elasticity KW composites KW plates and beams of complex shape KW multigrid finite elements KW microapproach KW small error JO Bulletin of KSAU AU Matveev, A.D. PY 2017 IS PB Krasnoyarsk State Agrarian University