×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Are you an
Engineering professional?
Join Eng-Tips Forums!
• Talk With Other Members
• Be Notified Of Responses
• Keyword Search
Favorite Forums
• Automated Signatures
• Best Of All, It's Free!

*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.

(OP)
Hi,
One of the design requirements for my offshore structure is an impact from a mass with a given velocity. (Mass and Velocity are given.)
I am looking for a realistic way to translate that "impact load" into an "equivalent static load", and geting rid of doing any impact dynamic analysis.
Here is my methodology: m (mass) and V(velocity) are given, so I know the input energy is 0.5MV^2.(eq.1)
On the other hand I know if a force of F applys on my structure, it makes it deflect about "X". So the energy absorbed by the structure at that point is 0.5F.X.(eq.2) . Since it is a linear analysis, I konw F=K.X (eq.3)which K is the stifffness of that degree of freedome on the structure. By replacing (eq.3) into (eq.2) we will have: Absorbed energy=0.5K.X^2 (eq.4)
If we ignore the absorbed energy by the structure due to its damping and inertia, and also the energy lost at the impact, we could say: Input energy=Absorbed energy -> 0.5mv^2=0.5k.x^2
so x=v(m/k)^2. (K is known because we have our static model in place)
F=k.x -> F=m^2.(v/k)
Sorry for this long introduction. But I needed to generate a base for my question.
Do you think this result for F is a realistic value?

THis has been discussed a number of other times - go for a search forum wide and hopefully you will find something of use.

Regards,
Lyle

#### 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.

#### Resources

Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a partâ€™s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

# Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

• Talk To Other Members
• Notification Of Responses To Questions
• Favorite Forums One Click Access
• Keyword Search Of All Posts, And More...

Register now while it's still free!