Dynamic structural analysis of a fishing vessel

• Autorzy: Salas M. , Luco R. , Villavicencio R.

Warianty tytułu

PL

Niezawodność elementów okrętowych maszyn pokładowych w warunkach działania obciążeń wywołanych kołysaniami statku

• Języki publikacji: EN

Abstrakty

EN

Traditional methods to assess ship loadings are mostly based on static or quasi-static methods. When dynamic fluid loads are incorporated they are usually restricted to those originated in head seas, therefore only symmetric loads, such as vertical bending, are allowed into the analysis. It is a fact that in conventional monohulls major stresses arise from symatric loads, however when a ship operates in oblique seas the entire hull experiences combined symmetric and atisymmetric loads such as vertical benging (symmetric) and horizontal bending and torsion (antisymmetric). From the safety point of view, when a stress analysis of certain areas of the hull is carried out, in addition to symmetric loads it is desirable to include antisymmetric loads too. For instance, the direct longitudinal stress at the hull-deck shell junction will have contributions from both, vertical and horizontal bending moments. The hydroelastic analysis of marine structures allows any type of loadings to be included in a stress investigation. The theory is traditionally separated into two parts a "dry analysis" where a Finite Element Modal Analysis is carried out to determine the dynamic "in vacuo" characteristics of a structure. In this stage, a study of modal stresses can reveal potentially dangerous areas due to high stresses being concentrated at hull discontinuities. Having established the dynamic characteristics (natural frequencies, modal loads and shapes) of the "dry hull" a "wet analysis" is conducted to introduce all fluid effects such as wave loadings and hydrodynamic damping and added mass. This paper shows the modal stress analysis of a typical Chilean fishing vessel. Particular attention is given to highly stressed areas. As a general rule, antisymmetric loads have been traditionally neglected in a dynamic structural analysis, however, in this paper it is shown that they could contribute to increase stresses at specific places of the hull.

• Wydawca: Polish Academy of Sciences - Branch in Gdańsk Marine Technology Committee of the Polish Academy of Sciences
• Czasopismo: Marine Technology Transactions. Technika Morska
• Rocznik: 2003
• Tom: Vol. 14
• Strony: 209--226
• Opis fizyczny: Bibliogr. 10 poz., rys., tab.

Twórcy

autor

Salas M.

autor

Luco R.

autor

Villavicencio R.

• Institute of Naval and Maritime Sciences, Faculty of Engineering Sciences, University Austral of Chile Casilla 567, Valdivia, Chile,

Bibliografia

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