Page Comparison

h1.\\
Time
function for linear vs. nonlinear time-history analysis

{new-tab-link:http://www.csiberkeley.com/}CSI{new-tab-link} Software handles the initial conditions of a time function differently for linear and [nonlinear|kb:Nonlinear] time-history [load cases|kb:Load case]. 

A description is as follows:

- *Linear cases* always start from zero, therefore the corresponding time function must also start from zero.

- *Nonlinear cases* may either start from zero or may continue from a previous case. When starting from zero, the time function is simply defined to start with a zero value. When analysis continues from a previous case, it is assumed that the time function also continues relative to a previous value. A long record may be broken into multiple sequential analyses which use a single function with arrival times. This prevents the need to create multiple modified functions.


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*Related Incidents:*
* 23640: Load with uniform time history  in nonlinear direct-integration time-history analysis

* 25662: Triangular time function starting with nonzero value in nonlinear direct-integration time-history analysis, see especially the 6/23/2010 memo from Bob
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