Linear scaling

[ble31980]

I came across the phrase linear scaling when reading some material about structural analysis and load distribution and I have not been able to find out what the phrase means. Does anyone have a definition? I have asked a few people at work and they are not familiar with the phrase, so I am wondering if it is also known as something else? Thanks for your help.

 

[271828]

Wow, this is done in so many situations that it's hard to know which you're looking for. Examples:

Say I know that the deflection for a steel beam due to 1.5 kips/ft is 1.25 in. and want to know the deflection due to 2.0 kip/ft. Linearly scaling it up: 1.25 in. (2/1.5) = 1.67 in.

Loads are linearly scaled up using load combination factors.

If the moment of inertia for a 6 in. wide plate is [whatever], then the MOI for an 8 in. wide plate is [whatever]*(8/6)

If a 2 lb sinusoidal load causes 0.5%g acceleration, then a 3 lb load causes 0.5*3/2

The examples are endless.

 

[ble31980]

Sorry for the ambiguity of my post. Specifically, I saw this when reading about the distribution of loads in a braced frame structure. It was refering to taking the total vertical load of a structure and determining the load in a brace member by linear scaling of the force. Hope this clarifies my question. Thanks for the response.

 

[msquared48]

Are you referring to the Maxwell Diagram for solving loads in pinned trusses?

Mike McCann
McCann Engineering