Structural Detail Design - Component from First Principles

An overview of what you get with services for structural design of foundations.

Structural detail design can be anything from a single small component to an entire ship.  In this case, we will focus on the small component and address the whole ship in a separate post.  The detailed design of a small component is usually for simple situations.  Simple can happen for many reasons.

1. The component itself is very simple.  Like a stanchion.
2. The detailed design is a small detail of a larger system.
3. The majority of the component was already designed with more thorough methods.

Detailed design is limited to a simple set of analysis methods, usually based on spreadsheet calculations.  The advantages are that spreadsheet calculations happen very quickly and cost effective.  The downside is that if you use a simple method on too complicated of an application, the engineer with compensate by requiring ridiculous safety factors.  So it is easier to provide a list of typical situations that can use first principles calculations.

• Beam sizing for a single loaded beam
• Plate sizing
• Weld sizing
• Joint detail for joining two structural members
• Bolt pattern for foundation of a small piece of machinery
• Weld pattern for foundation of a small piece of machinery
• Sizing for torsion of a small shaft (not the main propeller)

In all these things, you are talking small simple structures with a straight-forward question:  how much steel do I need.  Avoid questions like:  What is the best way to design this?  How can I make it better?

First principles calculations work best on some detail that you will repeat many times.  Think about stiffener joints between decks.  That is a great example for first principles calculations.  The engineer designs for one situation and it can be used on hundreds of individual stiffeners.

Deliverables

Don’t expect any fany reports here.  The report may take longer to write than the actual calculations.  You will normally get a letter or memo with some attached calculations laid out in spreadsheet format.  Sometimes it will even be hand calculations.  In any case, the work should be legible and clearly documented.

Specifically ask the engineer to document their assumptions.  This is the part where the engineer applies some creativity to find the right math to fit your situation. Sometimes those assumptions limit you to specific applications only.

Budget

First principles calculations are fast and simple.  They should only take 1 – 2 weeks at most.

Schedule

Fast calculations give fast turn-around.  You should get results within 1 – 2 weeks.

Client Input

You will probably need to provide structural drawings for your vessel.  And some information to help the engineer determine how the structure will be loaded.