×
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

static load conversion

static load conversion

static load conversion

(OP)
Hello guys !!
I am working on a project of static analysis( backhoe loader) ...
this vehicle hits the other vehicle at the speed of 5.71 kph (@1100 rpm , mass = 8000kg ).
how can we convert these load into a static load ...?

pls help me out ...

with thanks
R. vinod raj

RE: static load conversion

To obtain a force you need the length of impact time or the deformation of the components in the impact.

RE: static load conversion

Or... otherwise termed as the overall rate of deceleration from the initial to the final speed.

Mike McCann, PE, SE (WA)


RE: static load conversion

You can make different assumptions about the time or the distance or the stiffness and come up with different answers. And change those assumptions and come up with other answers.
In some situations like that, they may do actual testing (I've seen video of that with crash-resistant barriers)
In some situations, the requirements may be based on absorbing energy (I've heard of that as a criteria for roll cages on bulldozers, etc.)

RE: static load conversion

vinoamcr,

As everybody is noting, impact is a dynamic event, not a static one. The force is a function of deceleration, due to springy components, deforming components, and the thing you hit, moving.

You can make some assumptions, and get an equivalent static force, but those assumptions may make your analysis nonsense.

--
JHG

RE: static load conversion

The easy way:
If:
  • v0-initial velocity
  • v-velocity at the moment of impact
  • s- the path from v0 to v
  • a- acceleration
Than acceleration is equal to: a= (v² - v0²) /(2*s). Hence, the v0=0 m/s => a=v²/2s.
Therefore, the force is F=m*a

The other way is to work out the collision, with impulse...

However, you must be aware that this isn't a static force, because you don't have a gradual increase of the force over time. You have an impact -dynamical response. Look the attachment

Live long and prosper!

RE: static load conversion

P.S., if this is for your school work, and you have trouble with the impulse method (more accurate) notify me...

Live long and prosper!

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