engleski

Longitudinal strength and racking analysis of car carrier-5400 cars

Faculty of Mech. Eng. and Naval Arch. and Uljanik Shipyard have performed have performed 3D FEM analysis of Yard 441-442 using MAESTRO software available at University of Zagreb. The coarse-mesh, full-asymmetric, global car carrier FE model was developed (Pt B,Ch 7, App 2). It simultaneously provides all needed data for the (1) longitudinal strength analysis and (2) racking analysis of three watertight bulkheads (Fr 51 / M / 147) caused by the transverse racking induced forces. Full ship 3D FEM model has 35 983 DOF and 20 690 macroelements (10 527 stiffened panels and 7 343 beams). Loading condition 5 (Cars on decks 1 to 11, arrival) was adjusted to R.I.N.A requirements for racking (Pt B, Ch 5, Sections 3-6 and Pt B, Ch 7, Appendix 3. Maestro loadcases 1 and 2 ( corresponding to heel to STB and PS), are prepared. Loading condition 9 (Cars and trucks on decks 1 to 10, departure) was adjusted to R.I.N.A requirements for longitudinal strength analysis based on Pt B, Ch 5, Sections 2-5 and Pt B, Ch 7, App. 3. Maestro loadcases 3 - 6 are prepared for analysis of RINA requirements. All masses (light ship, cars,etc.) were given corresponding accelerations based on the acceleration vector components calculated from the Rules (Pt B, Ch 5, Section 3), Car masses were concentrated in mesh nodes of the corresponding decks or distributed on hoistable decks according to the force plan supplied by the Yard. Pressures are calculated according to RINA requested distributions. Stress levels were adjusted to R.I.N.A Rules (Pt B, Ch 7, Section 4). Ship satisfies R.I.N.A. requirements. Comments are given for areas of higher stress or lover safety with respect to Maestro collapse and serviceability criteria adjusted to RINA safety factors.

car carrier; finite elements; MAESTRO modeling; longitudinal strength; racking analysis

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