Section 4 Direct calculations
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules for the Application of Sandwich Panel Construction to Ship Structure, July 2022 - Chapter 4 Design Basis and Scantling Determination of Primary Structure - Section 4 Direct calculations

Section 4 Direct calculations

Parent topic: Chapter 4 Design Basis and Scantling Determination of Primary Structure

4.1 General

4.1.1 This Section gives the basic principles and requirements to be followed when carrying out direct calculations.

4.1.2 The scantlings of primary steel support members are to be examined by the applicable ShipRight Structural Design Assessment procedure for the particular ship type, see Pt 3, Ch 16, 3 Structural design assessment of the Rules and Regulations for the Classification of Ships, July 2022.

4.1.3 In general the guidance provided in the applicable ShipRight procedure should be followed except with respect to the modelling of the steel sandwich panel.

4.2 Structural modelling of sandwich panel

4.2.1 In this sub-Section requirements are provided for the modelling of the sandwich panel.

4.2.2 In general, the plate element mesh is to be sufficiently fine to recover the stress at the panel boundaries. The recommended mesh sizes for sandwich structure are:

  1. for the core material two elements between the steel face plates;

  2. for the face plates a mesh size equal to the core thickness. Care is to be taken so as the aspect ratio does not to exceed 1:4.

4.2.3 Top and bottom plates of the steel sandwich panel are to be represented by shell elements and the core material by solid elements. The core material may be modelled using shell elements where it has been demonstrated that the shell element method will give equivalent result as obtained by 3-D solid element method. The nodes of the shell elements are to be placed at a distance d from each other, see Figure 4.4.1 Modelling of sandwich by Finite Element with a combination of solid and shell elements.

Figure 4.4.1 Modelling of sandwich by Finite Element with a combination of solid and shell elements
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