...

**Cyclic **

...

** pushover **

...

** analysis**

...

may

...

be

...

performed

...

using

...

either

...

of

...

two

...

approaches,

...

outlined

...

as

...

follows:

...

# Sequence of nonlinear-static

...

# load

...

# cases

...

Cyclic

...

...

analysis

...

may

...

be

...

performed

...

through

...

a

...

sequence

...

of

...

chained

...

pushover

...

analyses.

...

Two

...

key

...

aspects

...

of

...

this

...

approach

...

include:

...

- Each

...

- pushover

...

- analysis

...

- would

...

- be

...

- pushing

...

- the

...

- structure

...

- in

...

- the

...

- direction

...

- opposite

...

- to

...

- that

...

- of

...

- the

...

- preceding

...

- pushover

...

...

...

- .

- Each pushover load case, aside from the first, would use stiffness at the end of the previous pushover load case.

# Time-history load cases

An alternate approach is to use a single nonlinear time-history load case.

Some special considerations are necessary when using a time-history load case to model applied loading, listed as follows:

- Load should be scaled up or down to achieve the monitored pushover displacement desired for each cycle.

- The time function should consist of linear segments which apply the loads in one direction and then the reverse, possibly with a constant segment to hold loads before their reverse.

- For each cycle in the sequence, the peak positive and negative time-function values must be found, starting with the first cycle of load application.

A sample of a time function is shown in Figure 1: