Purpose
PULS is a computerised buckling code recognised by DNV for strength assessment of stiffened thin plate elements in ship and offshore structures.
It is founded on advanced mathematical models implemented into easy and intuitive stand-alone software and DNV’s Nauticus Hull programs.
Benefits
The benefits are more accurate assessments of buckling and ultimate capacity limits of thin walled hull elements and larger ranges of application than possible with simpler semi-empirical codes. Thus the prevention of local overloading, permanent sets and collapse can be enforced with higher confidence than possible with simpler rule formulations.
Other benefits are a stand-alone software giving 3D graphics of buckling modes, redistributed stress flow etc., all added value information giving the user a deeper insight and which can be used for design optimisation and more efficient use of the material.
Moreover, the code is streamlined towards modern computerised design calculations and the engine (solver) can be implemented as a post-processor in linear FE design programs.
Features
The PULS code has many features which make it convenient to use as a design tool.
The user interfaces are very easy and compact and more or less self explanatory. The output include simple parameters such as usage factors and buckling capacities and added value information about size and shape of buckling deflections, redistributed stress pattern etc. are available.
Automatic modes for assessing the ultimate capacity limit under combined loads is provided and it is simple to cut and paste numbers into Excel or other software e.g. for easy comparisons with other codes and analyses.
The standalone software has two interfaces;
Visual Basic Advanced Viewer (AV)
Excel spread sheet using the same input/output file format.
Moreover, the PULS engine (solver) has been implemented into different DNV Software modules such as the Nauticus Hull Section Scantling program, ABC buckling postprocessor etc.
As per February 2007 the code is accepted by DNV as a general buckling code for ship and offshore structures being a part of the Recommended Practice DNV-RP-C201 “Buckling Strength of Plated Structures”. It is also used as part of the DNV’s voluntary Class notation CSA for dimensioning plates, stiffeners and girders and it is accepted by IACS as an advanced buckling method in the Common Structural Rules (CSR) for double skin oil tankers.