User:Eas4200c.f08.wiki.c/homework report 5

=Matlab Code=

The Matlab Code used in the following analysis is provided below.

'Part 1' is commented out when doing the analysis for 'Part 2' and vice versa.

=Stringer Analysis=



The above shows the diagram of the NACA2415 airoil with only the stringers considered in the analysis and ignoring the contributions of the skin. The important results are given below.

I_22 =

3.5173e-005

I_23 =

9.5347e-007

I_33 =

6.6954e-007

beta =

1.5010

maxsigmaxx_ylocation =

0.4999

maxsigmaxx_zlocation =

-7.8576e-004

maxsigma_xx =

4.1620e+008

M_zult =

2.1625e+005

M_yult =

-8.6498e+004

=Full NACA2415 Airfoil Analysis=



The diagram above shows the centroid location and neutral axis of the airfoil when the skin is considered along with the stringers. The important results are as follows:

I_22combined =

3.5628e-005

I_23combined =

7.9850e-006

I_33combined =

1.2106e-004

beta =

0.1771

maxsigmaxx_ylocation =

0.4999

maxsigmaxx_zlocation =

-7.8576e-004

maxsigma_xx =

4.1620e+008

A close up of the difference in the centroids of the stringers and the total airfoil is provided below for easier analysis.



As seen, the location and magnitude of the max normal stress barely changes, which is expected due to the centroid barely changing with the addition of the skin to the analysis.

The highest bending stress is in a stringer occurs in stringer H due to its distance from the neutral axis. It's value is

maxsigma_xx1 =

3.3823e+008

This causes the ultimate bending moments experienced by the stringers to be:

M_zult =

3.1349e+003

M_yult =

-1.2539e+003