Static mechanics beam question solved using set of 4 simultaneous equation arrays

[s3380734]

[h=2]Hi All,

this is my first post in this forum so i hope im doing it correctly, please let me know if not.

I'm solving a static calculation that resolves into 4 simultaneous equations. The static beam is shown here:

I've derived 4 equations from this beam and they are shown below:

FCz + FDz = -4579.30 [1]

39*FDx + 306*FDz = 2253019.536 [2]

FCx + FDx = 0 [3]

FCx*-39 +FCz*-306 = 3654287.784 [4]

I've put these coefficients in to Matrix A and the constants in to Matrix B:


A
0 1 0 1
0 0 39 306
1 0 1 0
-39 -306 0 0

B
-4579.308
2253019.536
0
3654287.784

I've then used MMULT(MINVERSE(A),B).

However, my output comes out at as:

FCx -131072
FCz 8192
FDx 131072
FDz -8192

This cannot be correct because FCz + FDz must equal to -4579.308 but from these outputs would = 0? Not sure what I'm doing wrong, can anyone assist?[/h]

 

[s3380734]

Hi, here is the picture of the beam:
https://ibb.co/cX4nLz

 

[Macropod]

Cross-posted at: https://www.excelforum.com/excel-fo...ng-set-of-4-simultaneous-equation-arrays.html
Please read Mr Excel's policy on Cross-Posting in rule 13: http://www.mrexcel.com/forum/board-announcements/99490-forum-rules.html

 

[s3380734]

Cross-posted at: https://www.excelforum.com/excel-fo...ng-set-of-4-simultaneous-equation-arrays.html
Please read Mr Excel's policy on Cross-Posting in rule 13: http://www.mrexcel.com/forum/board-announcements/99490-forum-rules.html

Hi Macropod,

apologies for cross posting without a link, I am now aware of this rule and will place a link in my OP if I do it in future.

Cheers

 

[s3380734]

Cross-posted at: https://www.excelforum.com/excel-fo...ng-set-of-4-simultaneous-equation-arrays.html
Please read Mr Excel's policy on Cross-Posting in rule 13: http://www.mrexcel.com/forum/board-announcements/99490-forum-rules.html

Hi macropod,

I'd like to proceed with this thread only on the excel forum and delete the thread on this website. I cant figure out how to do so, can you please advise how to do this?

Cheers,

 

[Macropod]

There is no provision for users to delete threads on either site; it's your choice as to which one you pursue any further discussion on.

 

[s3380734]

There is no provision for users to delete threads on either site; it's your choice as to which one you pursue any further discussion on.

Ah I see, ok thanks Macropod.