Onderzoeksopdracht Maritieme Techniek

Nr

01-026

SOC2

Sectie opdrachtgever

Ship and Offshore Structures	Naam opdrachtgever

Ir. J.H. Vink

Datum

March 2002
Titel	Fatigue
Trefwoorden

Inleiding

Due to the extensive use of steels with higher tensile strength in ship constructios, combined with more optimized constructions due to extensive application of advanced analysis methods (long term predictions of hull bending moments with ship motion analysis, and application of FEM for response analysis), fatigue has gradually become an important failure mechanism for ships.

Classification societies have already, or are in process of, implementing fatigue life evaluation methods in their rules for classification of ships.

This research focuses on the problem of fatigue life evaluation, methods for repairing details which suffer from fatigue cracking, evaluation of rest life for repaired constructions and experimental verification of the predictions made.

The research will be applied to the simple configuration of an axially loaded steel strip having a central crack with length, 2a, equal to 0.5*width of the strip, see figure 1. The strip is loaded in tension with an axial force which varies with constant amplitude between Fmin = 0.1*Fmax and Fmax.

Figure 1: Axially loaded strip with a central crack.
Vraagstelling
Uitwerking en eisen

Contents:

Study literature on fatigue and methods for evaluating fatigue life,

Make 3 proposals for repair of damaged test piece,

Make fatigue life predictions for the 3 alternatives as propose,

Make test pieces for the 3 repaired variants,

Perform fatigue tests,

Evaluate results.

Basic knowledge:

Colleges: Ship and Offshore construction, 2nd and 3rd year MT
Opmerkingen

Literature:

Relevant chapters on fatigue from the Rules for Classification of Ships by: Lloyd’s Register, Germanischer Lloyd, Bureau Veritas, Norske Veritas

Begeleiding

Naam	Sectie	Tel	E-mail
Ir. J.H. Vink	SOC	85923	j.h.vink@wbmt.tudelft.nl
Toegewezen aan:

Onderzoeksopdracht

Grimmelius

2002-07-16

Wim Thijs

Maritieme Techniek