Section Classification BS 8118-1-1991

Section Classification of 'Non-W 'Non-Welded' elded' Thin Elements [BS 8118-1: 1991] by: I.R. Itum

Created: 28-July-2012

Unreinforced Unreinfor ced Flat Fla t Elements §01. Internal Elements Under Uniform Compression §01-1. Farthest Farthest Element

 b  60mm

→

flat width of the element

t  2.5mm

→

the thickness of the element

y1  97.94mm

→ the distan ce of the most severely stressed fibe r from from the th e NA of the gross section.

y2  96.14mm



the distance of the element under  consideration from from the NA. NA. → limiting

250MPa y 1  p o

M

→

 p o  160MPa ε  

Compression Side



 1.262

y2

stress

→ stress

parameter 

β   b  t  24 → width to thickness ratio ratio for internal u nwelded element β1  18 ε    22.71 → lower limit of slenderness ratio

8118-1:1991 βo  22 ε    27.756

→ high er

8118-1:1991  Element Classifica C lassifica tion tio n

Tension Side

►

Table 4.3, BS

limit of slenderness ratio ratio for internal unwelded el ement ► Table 4.3, BS

► Clause

4.3.3.4, BS 8118 -1-1991

"Fully Compact" if   β  β1

 "Semi-Compact"

"Semi-Compact" if   β1  β  βo "Slender" if   β  βo  Effective thi ckness  x 

 β 

ε  

 19.023

32 220 k L  min   1.0   1

 

 x 

2

 x 

teff   k L t  2.5mm

 by: I.R.Itum, C.E.

  → effective

→ thickn ess

reductio reductio n factor for for unwelded internal element & Table K.1 (curve C), B1 8118-1-1991

► Figure

4.5, curve C

thickness

Section Classification BS 8118-1-1991.xmcd 1/5