- #1

jellicorse

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## Homework Statement

I am trying to calculate the flexural rigidity across the span of a guitar soundboard.

The soundboard is comprised of a number of struts, the shape of which can be approximated to a triangular section sitting on a rectangular section. This makes for straightforward calculation of the second moment of area.

Diagrams

I can see how to calculate the flexural rigidity of each soundboard-brace section: by finding the overall second moment of area of the section (using parallel axis theorem) and then multiplying this by the Young's Modulus (

*E*). (In this case, a standard value for the material in question - Spruce at 10GPa).

What I can not see how to do is to find the overall flexural rigidity across a span of the soundboard.

I'd be very grateful if anyone could tell me how to approach this.

## Homework Equations

Parallel Axis Theorem:

[tex]I_{AB} = I_C + l^2 A[/tex]

[tex]Flexural Rigidity = EI[/tex]

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