Is it possible to apply a concentrated force on the surface of an element? The point where the load acts is not one of the nodes of the element, as a result of which I cannot use the JOINT LOAD option.
Yes, it is possible to do this. In Section Technical Reference of STAAD Commands > TR.32 Loading Specifications > TR.32.3 Element Load Specifications > TR.32.3.1 Element Load Specification - Plates of STAAD.Pro Help, if you look at the syntax of the element pressure loading, you will find the following :
element-list PRESSURE direction x1 y1 x2 y2
In this syntax, (x1,y1) and (x2,y2) represent the corners of the region (on the element) over which the PRESSURE load is applied. However, if you omit the terms (x2,y2), the load will be treated as a concentrated force acting at the point (x1,y1), where x1 and y1 are measured as distances, from the centroid of the element, along the local X and Y axes, of the point of action of the load.
Thus, if you want to apply a 580 pound force along the negative global Z direction at a distance away from the centroid of (1.3,2.5)feet along the local X & Y axes of element 73, you can specify the following commands
UNIT POUND FEETLOAD 1 CONCENTRATED LOAD ON WALLELEMENT LOAD73 PR GZ -580.0 1.3 2.5