Linear Load

[rmFEAP]

Hello again,

I am using FEAP 8.4 so my question relates to that version.

I want to use a distributed load on a 1 dimensional beam (as it is known from basic courses of technical mechanics). So Let us say that q = 5 N/mm over a cantilever beam with a length of 1000mm. How do I implement this in FEAP? I found the CSURface command but it does not work (maybe I made a mistake).

An option I know from writing own programms is to discretize the line load with shape functions. But as the neumann conditions are written into the input file, I shouldn't add this to the residual. If I calculate the resulting nodal forces and moments from the discretization and put them under the FORCe command, the displacment is to small compared to the analytical solution.

So how can I implement this problem to an input file?

Thank you in advance!

[Prof. R.L. Taylor]

Most beam and shell elements have this type of load as a "body" type force.  See the manual in Sect 7.15 (ver8.5 manual).  You can specify "LOAD,,q" where q is the loading intensity.  The extent though is over all elements that refer to the material set. 

[rmFEAP]

Thank you for the reply professor. This works out well!!
 
Now there is a second question (not Input file related but I dont want to open a new thread for this). I wrote an element for phase field modelling of fracture and want to apply a linear load on a cantilever beam. How do I add those loads when I use my own user routine?
Is there a special force vector?

[Prof. R.L. Taylor]

If you are using solid elements you can use CSURf loading or the PRESsure element.

If you are using a structural element (frame, plate, shell) then you could code the loading as a body type force in the element routine.