Increment - CAESAR II - Help

CAESAR II Users Guide

Language
Русский
Product
CAESAR II
Search by Category
Help
CAESAR II Version
12

Specifies the node number increment used to step from Start Node to Stop Node. Each node that is incremented between the start and stop nodes is loaded with the value of Force. This value is optional.

Example 1

A pressure pulse traveling in the line causes the line to shake at about 2 hertz. The magnitude of the pressure loading is estimated to be about 460 lb. The pressure wave travels from 95 to 100. The harmonic force to model this load is shown as follows. The magnitude is divided by 2 because the total variation in the dynamic load is a function of the cosine, which varies from -1 to 1. To find the true response magnitudes from a positive-only harmonic load pulse, a static solution with 460/2 lb. acting in the +X direction is superimposed on the static 460/2 lb. solution to provide the constant shifting of the load axis. There is a negative load at node 95 due to the negative sign on the cosine. The pressure pulse is always positive, and a negative load never exists. The superposition of the 460/2 static solution assures that the dynamic load (and probably the resulting displacements) is always positive.

460 LB pressure load at 2 Hertz

460/2 X 0 95

Example 2

A pump is shaking in the X-Y plane. The pump axis is along the global Z axis. The magnitude of the dynamic load is calculated to be 750 lb. from the manufacturer-provided masses and eccentricities. Apply this rotating equipment load on the inline pump at node 350. The X and Y loads are 90 degrees out of phase with one another. When the X load is at its maximum the Y load is zero, and when the Y load is at its maximum the X load is zero.

Estimated eccentric load on inline pump DOH-V33203001

750 X 0 350

750 Y 90 350