Skip to main content
AH_108849694-Participant
4-Participant
Jan 8, 2025 1:22 AM UTC
Solved

What's wrong with my integration to calculate section properties

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. 

 

AH_10884969_0-1736298599735.png

Appreciate any help please. 

terryhendicott
terryhendicottAnswer
21-Topaz II
Jan 15, 2025 7:36 AM UTC

Capture.JPG

View in thread

11 replies

LucMeekes23-Emerald V
23-Emerald V
Jan 8, 2025 8:42 AM UTC

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:

LucMeekes_0-1736325472675.png

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:

LucMeekes_1-1736325674496.png

 

 

Is that intentional?

 

Success!
Luc

Translate
    AH_108849694-ParticipantAuthor
    4-Participant
    Jan 8, 2025 10:53 PM UTC

    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. 

     

    AH_10884969_0-1736376602336.png

     

    Translate
    terryhendicott
    terryhendicott21-Topaz II
    21-Topaz II
    Jan 9, 2025 8:25 AM UTC

    Hi,

    Try this method of calculating section properties.  Starts with definition of the section by xy coordinates

    Cheers

    Terry

    Translate
    Terms & ConditionsAccessibility statement