engleski

FEM Analysis of Livestock Carrier Construction Blocks

Faculty of Mech. Eng. and Naval Arch. has performed 3D FEM analysis of three construction blocks CB1, CB2 and CB3 (deck 3-6 in two variants and deck 7-10 ) of Yard 428 using MAESTRO software available at University of Zagreb. The objective of the analysis is to investigate the structural strength and deformations of construction blocks when positioned on undercarriage (little train) and when lifted by the crane in fulfillment of standard MAESTRO adequacy parameters (buckling, yield) and Designer's requirements (von Mises equivalent stress < 200 N/mm2). Each 3D FEM model has approximately 4590 DOF and 433 macroelements. Two loadcases ( LC1- block on undercarriage and LC2-lifted by crane) are generated for each CB using given weight distribution and adjusted to correct position of block centre of gravity. Dynamic factor is given as 1.25 by the Designer. This Report gives stresses and magnified deflections of construction blocks (CB) in Figures 1 -7. Fig. 1 : Maximal normal stresses in flanges of girders and frames for CB1 / LC1 (deck 3-6 construction block on under carriage) are ploted . Stresses and MAESTRO criteria are satisfied. Fig. 2 : Maximal normal stresses in flanges of girders and frames for CB1 / LC2 (deck 3-6 construction block lifted by crane) are ploted . Stresses and MAESTRO criteria are satisfied. Fig. 3 : Maximal normal stresses in flanges of girders and frames for CB2 / LC2 (deck 3-6, between frames 81-91, construction block lifted by crane) are ploted . Stresses and MAESTRO criteria are NOT satisfied.. Fig. 4 : Additional pillars between decks 5 and 6 are installed in model CB2. Maximal normal stresses in flanges of girders and frames for modified CB2 / LC2 are ploted . Stresses and MAESTRO criteria are now satisfied. Fig. 5 : Maximal normal stresses in flanges of girders and frames for CB3 / LC1 (deck 7-10 construction block on under carriage) are ploted . Stresses and MAESTRO criteria are satisfied. Fig. 6 : Maximal normal stresses in flanges of girders and frames for CB3 / LC2 (deck 7-10 construction block lifted by crane) are ploted . Stresses and MAESTRO criteria are NOT satisfied. Fig. 7 : New position of lifting ropes is suggested. Maximal normal stresses in flanges of girders and frames for CB3 / LC2 (deck 7-10 construction block lifted by crane) are ploted . Stresses and MAESTRO criteria are now satisfied. With proposed modifications all CBs satisfy all loadcases requested by Designer.

construction blocks; finite elements; MAESTRO modeling;

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