Upload
others
View
1
Download
0
Embed Size (px)
Citation preview
•Stress Concentrations (Openings)
•Opening too close to edge
76 BV Rules
•Stiffener opening & lightning hole
•Compensation around opening •Elliptical opening
•Importance of Continuity (good examples)
•Gradual change of section
77 BV Rules
•Face flat continuity
•Face flats aligned and welded
•Gradual change of thickness
•Pillar side continuity
•Discontinuity •Ensuring continuity can be made by :
78 BV Rules
•Avoiding discontinuity (abrupt change of section) in the first place
•
•If discontinuity is unavoidab•Lleo,nagllietuvdiaintealists effects. This can be achieved by adding swtreulcdteudraolnmfleomorbe+rnsoin line with the discontinuity, e.g. adding brackebtsraectck.et
•Misalignment
•Misalignment causes discontinuity
•It is important at design and construction stage to ensure that structure is made continuous by correct alignment
79 BV Rules
•Overlapping + too many welds
80 BV Rules
•Stiffeners miss each other
•Plate insert with short face flat
•Plate welded to web + large sniped bracket
•Good detail of structural design avoids future problems
•Importance of Detail •Continuity and Alignment!
•Importance of Shape
•Well shaped brackets below deep beam
81 BV Rules
•Well shaped bracket silhouettes
•Stresses flow through the structure according to the shape and the cross sectional area available •It has been shown that stresses flow around a corner with a gradient of approximately 1/2.5
•Corrosion
•Sheet corrosion •Sheet corrosion
•Scaling
82 BV Rules
•Corrosion (continued)
•Heavy corrosion with hole and crack
•Heavy corrosion
•Pitting
83 BV Rules
•Deformation & Buckling
•Hungry horse effect
84 BV Rules
•Deformation & Buckling (continued) •Tank top plating
85 BV Rules
•Tank top plating
•Lower frames
•Cracks
•Crack along butt weld seam with crack arrestor
+ gauged afterwards
86 BV Rules
•Corrosion cracks
•Cracks (continued)
•Crack along bottom edge of opening
•Cracks on floor to girder connection -
welded and collar plate fitted
87 BV Rules