Shear capacity calculation problem

[paulidi]

Hello seismosoft team.

I face a problem when calculating the shear strength of columns. I select columns and see that the shear capacity of the member (the reinforcement is the same across the member) is lower at the bottom of the member than at the top. The bottom of the member has more axial force (due to the self weight of the column so i expect that the shear force at the bottom is higher(a little) than the top. The problem is that the difference i see at seismobuild is huge . For example for the bottom of the column for local axe (2) V=170 , local axe (3) V=217 . At the top local axe (2) V=170(same) , local axe (3) V=283.

[paulidi]

Now i also see that the shear capacity changes a lot depending on the direction of the seismic force for elastic dynamic analysis. Specially for a shear wall its shear capacity ranges from 1316 to 534 kN for the strong axes and from 200 to 62 for the secondary axes. Why is this happening? The shear capacity is not affected so much due to the small change of axial load due to seismic actions.

[seismosoft]

If you see the expressions for the calculation of the shear capacity, this depends on several factors, including the axial load, the ductility, the Lv ratio and compression zone depth. You need to check all these values, in order to estimate the correct shear capacity
Seismosoft Support

[fsapostolou]

Hello,
When I run a pushover analysis, I observe that the shear capacity of each member varies with the load combination. Is it expected, or is there a mistake?

[seismosoft]

As we wrote in the previous post, the shear capacity, this depends on several factors, including the axial load, the ductility, the Lv ratio and compression zone depth. You need to check all these values, in order to estimate the correct shear capacity. However, the shear capacity is expected to vary.
Seismosoft Support