Time-history curves

In both static and dynamic time-history analyses, in addition to permanent loads, structures are subjected to transient loads, which may consist of forces/displacements varying in the pseudo-time domain (static time-history loads) or of accelerations/forces that vary in the real time domain (dynamic time-history loads). Whilst the type, direction, magnitude and application nodes of these loads comes defined in the Applied Loads module, their loading pattern, that is, the way in which the loads vary in time (or pseudo-time), is given by the time-history curves, defined in the Time-history Curves module. The latter comprises two interrelated sections:

• Load curves
• Time-history stages

Note: Time-history curves provide only the time pattern of the transient loads. Their full absolute magnitude is obtained through the product of time-history ordinates with the Curve Multiplier, defined in the Applied Loads module. This effectively means that time-history curves can be introduced in any given system of units, for as long as a coherent curve multiplier is used (e.g. if an accelerogram is defined in [g] and the system of units adopted by the user requires acceleration values to be defined in mm/sec2, then the corresponding curve multiplier should be 9810).