Linear structural stress analysis of a hull girder penetration and a short longitudinal bulkhead using finite element modeling
Contributors: Naval Postgraduate School (U.S.)
Publisher: Naval Postgraduate School; Available from National Technical Information Service
Published: 1997
Place of publication: Monterey, Calif; Springfield, Va
Language: eng
Number of pages: 49
Subjects: STRUCTURAL ANALYSIS; SHIP HULLS; STRESS ANALYSIS
Description: The objective of this study is to investigate structural shadow zones encountered in shipbuilding design using the      I-DEAS (Integrated Design Engineering Analysis Software) software. The term 'shadow zone' refers to areas of      low stress concentrations that are caused by lines of stress bending around structural discontinuities. Two ship      design situations frequently encountered that result in shadow zones are hull girder penetrations and short structural      longitudinal bulkheads. In both of these situations, a long-used rule of thumb is to construct a line with a slope of      1:4 originating from the. discontinuity that encompasses the area of low stress. The material within this line is then      considered ineffective when computing the section modulus. This can prove to be expensive. However, powerful      finite element analysis software is readily available that can analyze the shadow zones in greater detail and possibly      minimize the area considered ineffective. This study uses the I-DEAS software to develop finite element models of      the cited design situations for a U.S. Navy Frigate, FFG-7 class of ship. It conducts a static structural linear      analysis of the ship balanced on a trochoidal wave of height 1.1 VL. The results generated in this study validate the      rule of thumb in both situations.
Notes: Thesis advisor, Charles N. Calvano.

AD-A330 994.

Thesis (M.S. in Electrical Engineering) Naval Postgraduate School, June 1997.

Includes bibliographical references (p. 47-48)

dk/dk cc:9116 10/22/97.