×
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

Primary fragments impacting on concrete

Primary fragments impacting on concrete

Primary fragments impacting on concrete

(OP)
Does anybody out there know how to determine the impact on concrete from primary fragments, travelling at approx 2-3km/s?

Or a change of formulae to help.

RE: Primary fragments impacting on concrete

Hi Cniper

Primary fragments of what? What formula are you currently using or is it a secret.

desertfox

RE: Primary fragments impacting on concrete

We need more information in order to offer any constructive advice.

What size particles?  What is their shape?  How many of them per unit area?  What is the impingement angle?  What are the particles made of?  What type of concrete?  What strength concrete?

Formulae don't mean much when dealing with abrasion and durability of concrete.  Those are primarily strength and tested parameters.

RE: Primary fragments impacting on concrete

I'd suggest he means the particles produced from an explosion. Its whatever was blown up.

RE: Primary fragments impacting on concrete

OP asks "..how to determine the impact ...?"
My suggestions:
[a] Measure it by doing a MIL-STD-2105 Fragment Impact Test. (If you are government or a gov't contractor, DOD activities routinely do this.  Cost is in 4 digits.)
[b] Estimate it via empirical equations available in open source literature, e.g. google search the words "hertz concrete impact" to find journal papers.
[c] check out textbooks in explosive effects, rock blasting, terminal ballistics, etc.

The specifics will depend on the many variables mentioned in the previous posts.   

RE: Primary fragments impacting on concrete

(OP)
From the 4 replies you can see my dilema.  Concrete of about 1.5m thk, estimate 40 N.  Prior to testing etc, just a formula to get me started to give a handle on the outcome. The information onb the initial thread is all I have to work with,  ie lots of assumptions which is always the case in Engineering.

Thanks for your comments. Looking at spalling....Trying to determine the imapct from a detonation and although fragments of metal from a casing can be contained the sizes of cracks would be vast for gases to escape.

RE: Primary fragments impacting on concrete

There are, available on the web, design and construction handbooks for hardened buildings and facilities.  The only unknown that you appear to have is the size and weight of the fragments, which is described in MIL-DTL-46593B.

TTFN

FAQ731-376: Eng-Tips.com Forum Policies

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