What's wrong with my integration to calculate section properties

Forum|Forum|1 year ago
January 8, 2025
1 reply
2228 views

I am developing a sheet to calculate section properties of steel sections using Mathcad Prime 10, however I find the integration gives zero value for web thickness less than a number for my specific example.

see below screenshot and attached file. The Ay gives correct area, however the Ax doesn't. I have tried different values for tw which gives a correct result when it is larger than a certain number. For example in the I section if changed to 30mm, the integral gives correct answer.

Appreciate any help please.

1_section-properties.zip

Civil_Engineering

Best answer by terryhendicott

L

LucMeekes

23-Emerald IV

What is a right result, and what is wrong? It would be nice if you specify what you expect (versus what you get).

Your definition:

is overlapping.

The first row sets a value when -0.29m < x < 0.29 m and the last row sets a value when -0.77m < x< 0.77m.And the two middle rows specify the same range. So you get:

Is that intentional?

Success!
Luc

A

AH_10884969

Author

4-Participant

The formula and the integral calculate the area of the steel section below. The total area should be 202550mm2, however the formula calculates it 141800 which basically the total flange areas. The web area is not calculated (second and third rows).

I don't intend to have it overlapped, I am just unsure how to do it.