13 research outputs found
ALPS/ULSAP Software for Ultimate Strength Design of Steel Grillages under Combined Loads
peer reviewe
Least Cost Optimization of Large Passenger Vessels
The LBR-5 software allows optimizing ship structures according to objectives of higher
inertia, less weight and/or lower cost. This last criterion offers the choice between two approaches of
calculation. The first approach is based on a simplified assessment of the cost in which the total cost
is described by rather simple analytical functions which bring into play on the one hand the design
variables and on the other hand empirical parameters. In the second approach, the calculation of the cost
is based on data specific to the shipyard. The material cost is analyzed according to the first approach
while the cost of the labor considers each relevant operation of the ship building with respect to the
LBR-5 model. A survey of all the tasks was carried out at Aker Yards France, and a thorough study
made it possible to develop assessment tools of the labor cost for each operation as functions of the
design variables. Plate straightening operations are also considered in this analysis. This paper presents
a cost-based optimization study carried out on a large passenger ship structure with more than 600
design variables, by the use of the detailed approach for the cost calculation. The structural model has
been formulated on the basis of technical documentation prepared by Aker Yards France. The loads and
strength criteria applied on the model are considered according to classification society rules (Bureau
Veritas). Results and conclusions of the study are presented
Effect of Welding on Ultimate Compressive Strength of Aluminium Stiffened Panels
peer reviewe
Estimation de la résistance ultime de poutre-navire: Analyse comparative de méthodes sur frégates
peer reviewe
Ultimate Strength of Longitudinally Stiffened Panels: Multi-Criteria Comparative Analysis
peer reviewe
Benchmark study on the use of simplified structural codes to predict the ultimate strength of a damaged ship hull
The objective of the paper is to evaluate the ability of simplified structural analysis methods, based on the Smith formulation to predict the ultimate strength of a damaged ship. Such methods are now widely accepted as a reliable and fast way to obtain the longitudinal strength of an intact ship. In order to extend these methods to damaged ships, first a benchmark study on the intact ship was performed in order for the differences between the methods to be evaluated. Afterwards the methods are applied to the same ship section but with damage, which was defined by removing the structural elements from the affected areas. These, in turn, were obtained from a previous study in which a collision was simulated using a finite element model. Results obtained for the ultimate strength were compared against each other and with the results of the finite element analysis. Aside from some exceptions, the results of the approximate methods agreed well with each other for the intact and damaged conditions. The simplified methods are more conservative than the finite element analysis in hogging while they seem to give a very good approximation to the result for sagging with some of them overestimating this valu