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13-Aquamarine
April 10, 2024
Solved

Sectional properties of reinforced concrete section

  • April 10, 2024
  • 1 reply
  • 1162 views

Could someone help me to find the Area, CG and Second moment of area of a cross section using the two matrices SEC and CR.

Best answer by terryhendicott

Hi,

Here is a mathcad 15 file that gives area, cg, I in both x and y of a section defined by coordinates.

All you need to do is convert it to Prime.

It works with origin = 0.

Cheers

Terry

1 reply

25-Diamond I
April 10, 2024

According the erroneous calculation of a:

X and Y must be column vectors, otherwise (you defined them as row vectors) you would need two matrix indices to access single elements of them. You may use the transpose operator for displaying X and Y, but not when you define them.

The i in a.i has to be a vector index, not a literal index as you typed.

In your sheet you have ORIGIN set to 1 (instead of the default value 0). So your range must run starting from 1 as there is no element with index 0.

Furthermore i must only run up to 4, as you are using i+1 as index and the last index in your vectors is 5.

Werner_E_0-1712752288021.png

 

21-Topaz II
April 11, 2024

Hi,

Here is a mathcad 15 file that gives area, cg, I in both x and y of a section defined by coordinates.

All you need to do is convert it to Prime.

It works with origin = 0.

Cheers

Terry