×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

PMMA screen failure

PMMA screen failure

PMMA screen failure

(OP)
Gents,

I have a PMMA screen of around 800mm x700mm and 6mm thick. If I were to scored the sheet 3mm deep of v shape grove and from one corner of the sheet to another in the form of X. If the sheet is then subjected to impulse pressure of @ 20KPa. Do you think the sheet will break into small pieces or fail at the groves??

RE: PMMA screen failure


That is low pressure, but still over a tonne of load on the sheet. I would be very surprised if it did not fail in short time. The life will be very dependant on the radius at the bottom of the grove.

Regards
Pat
See FAQ731-376: Eng-Tips.com Forum Policies for tips on use of eng-tips by professional engineers &
http://eng-tips.com/market.cfm
for site rules
 

RE: PMMA screen failure

What you describe is very much analagous to a notched impact test. The stresses will concentrate at the crack tip (the sharp bottom of your groove) and the part will very probably fail there.

Chris DeArmitt

"Knowledge has no value except that which can be gained from its application toward some worthwhile end."
Think and Grow Rich - Napoleon Hill

RE: PMMA screen failure


I would guess it would fail along the grooves and leave sharp fracture edges.

At low temperature it may fail into many bits as well.

Harry

www.tynevalleyplastics.co.uk

RE: PMMA screen failure

(OP)
Thank you all for your contributions

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources