www.sefindia.org

STRUCTURAL ENGINEERING FORUM OF INDIA [SEFI]

 Forum SubscriptionsSubscriptions DigestDigest Preferences   FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups  RegisterRegister FAQSecurity Tips FAQDonate
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log in to websiteLog in to websiteLog in to websiteLog in to forum 
Warning: Make sure you scan the downloaded attachment with updated antivirus tools  before opening them. They may contain viruses.
Use online scanners
here and here to upload downloaded attachment to check for safety.

A simple question about steel section properties

 
This forum is locked: you cannot post, reply to, or edit topics.This topic is locked: you cannot edit posts or make replies.    www.sefindia.org Forum Index -> Past Discussions Year 2004
View previous topic :: View next topic  
Author Message
Rudra Nevatia
...
...


Joined: 26 Jan 2003
Posts: 207
Location: Mumbai

PostPosted: Fri Nov 26, 2004 5:21 am    Post subject: A simple question about steel section properties Reply with quote

Dear Prof. Kalyanraman,

Very interestingly, 'Theory of Plasticity' by J.
Chakrabarty gives orientation of plastic neutral axes
as

tan alpha1
= 2b^2/(a^2+2ab-b^2) and

tan alpha2  
2a^2(1+(tan alpha2)^2)-(a+b)^2
= ------------------------------------------
2b^2(1+(tan alpha2)^2)-(a+b)^2.tan^2alpha2

where

2a     = length of leg along y axis
2b     = length of leg along z axis
alpha1 = angle between pna1 and z axes
alpha2 = angle between pna2 and y axes
pna    = plastic neutral axis

So, in general plastic neutral axes are not
orthogonal. Chakrabarty refers to the plastic neutral
axes as strong and weak principal axis of plastic
bending, a terminology I beg to differ from.

If the angle is constrained to bend along y or z axis
only, I suppose the neutral axis will be parallel to z
or y axis respectively and very close to the legs for
equal angles.

Prof. Trahair's paper 'Moment Capacities of Steel
Angle Sections' available at
http://www.civil.usyd.edu.au/publications/r809.pdf
deals with this topic.

Regards,
Rudra Nevatia

--- kalyan@civil.iitm.ernet.in wrote:

Quote:
Plastic neutral axis are calculated by equating
total area in tension to
be equal to the total area under compression about
the two principal
axes, which in the case of equal angles are UU nad
VV axes.

Kalyanaraman

rudra_nevatia@yahoo.com wrote:

Intutively, for an equal leg angle, plastic neutral
axes should be located close to the legs.

Rudra Nevatia

--- Robert.Nicolson@Subsea7.com wrote:



Quote:
Can someone plese tell me whether an angle, i.e. a
L
Quote:
shape has a plastic
neutral axis.
Because I have just used a program which gave me
Zpl,x & Zpl,y ( second
moment of areas ),
as both equal to 0, for an angle ?
















          
__________________________________

Take Yahoo! Mail with you! Get it on your mobile
phone.
http://mobile.yahoo.com/maildemo

























          
__________________________________

Yahoo! Mail - Helps protect you from nasty viruses.

Posted via Email
Back to top
View user's profile Send private message
Display posts from previous:   
This forum is locked: you cannot post, reply to, or edit topics.This topic is locked: you cannot edit posts or make replies.    www.sefindia.org Forum Index -> Past Discussions Year 2004 All times are GMT
Page 1 of 1

 

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You can attach files in this forum
You can download files in this forum


© 2003, 2008 SEFINDIA, Indian Domain Registration
Publishing or acceptance of an advertisement is neither a guarantee nor endorsement of the advertiser's product or service. advertisement policy