Seismosoft | Earthquake Engineering Solutions

Dear,
I would like to pushover analysis with inclined forces, other than 90°. For example, to 15°. I could say what is the procedure to be followed in those casi.Io I had thought of this:

For alpha = 15 °


first files

Applied loading
X direction, Fx = fcos (alpha) in the mass center of gravity
Y direction, Fy = Fsin (alpha) in the mass center of gravity

Response control in the X direction, 50 Steps, target displacement = 0.05

second-file

Applied loading
X direction, Fx = fcos (alpha) in the mass center of gravity
Y direction, Fy = Fsin (alpha) in the mass center of gravity

Response control in the Y direction, 50 Steps, target displacement = 0.001

At the end combine the displacements for each load factor:

s(15°)=(sx^2+ sy^2)^1/2

T(15°)=(Tx^2 + Ty^2)^1/2
for each load factor and build the push over curve

If it is not correct, please tell me the exact procedure.
regards

Dear mattia86,

The issues you raise are not really related to SeismoStruct, but rather to earthquake engineering in general, hence this Forum is not necessarily the right venue for such discussions (you should instead read scientific publications and text books, carry out parametric studies, discuss the matter within the research community).

In any case, we can certainly note that carrying out a quadratic combination (SRSS) on the ouput of a nonlinear analysis is questionable, since SRSS and alike have been developed with elastic linear analysis in mind only (indeed, combining results from two different nonlinear analyses may lead to response quantities that do not necessarily have a physical meaning or feasibility).

Having said the above, there are some researchers who do advocate the employment of SRSS to combine the results of nonlinear analyses (e.g. see papers on the employed of MPA to assess plan-irregular structures), hence you might indeed want to follow such road.

But, we repeat, this is a research issue, not a SeismoStruct usability one, hence we suggest this discussion (which could go on forever and attract quite opposing views) to be terminated here.

Seismosoft Support