FEAP User Forum

FEAP => Input File Issues => Topic started by: halleluja on December 02, 2019, 01:39:42 PM

Title: how input uniform distribute force load?
Post by: halleluja on December 02, 2019, 01:39:42 PM

Hi everyone,

pls first see the picture in attachment where a distributed shearing load, F = 6.25 (per unit length) is applied to the left edge (amounting to a total vertical resultant force of intensity 6.25*16=100).

My question is how can i define this boundary condition? Can i use EFORce, such as

Code: [Select]

EFORce
  1 48.0 0.0 100.0

Best

Title: Re: how input uniform distribute force load?
Post by: Prof. S. Govindjee on December 02, 2019, 03:20:02 PM

If you want to use EFORce, then you will need to divide 100.0 by the number of nodes on the edge.  EFORce places the same load on each node that it finds.  Note however that if you use EFORce, then your load will not be "consistent" with a uniformly distributed load.  If you want consistent nodal loads for a uniformly distributed load, then you should use the CSURface command:

Code: [Select]

CSURface
  TANGential
  LINEar
  1 48.0 44.0  p
  2 48.0 60.0  p
where p is the load per unit length value.  If you want a parabolic end shear then use QUADratic instead of linear; see the manual for details.

Title: Re: how input uniform distribute force load?
Post by: halleluja on December 03, 2019, 08:15:59 AM

Thanks for your reply.

But still got problem, that the displacement of top right corner (node number 25) is negative in y-directoin which should be positive because the traction of the left edge is positive in y-direction.

In attachment you will find the input file.

Best

p.s. i use version feap 8.4

Title: Re: how input uniform distribute force load?
Post by: Prof. S. Govindjee on December 03, 2019, 09:31:45 PM

Have you checked the loads in the output file to see if they are correct?  How about in the plot window using plot,boun and plot,load?

Title: Re: how input uniform distribute force load?
Post by: halleluja on January 09, 2020, 05:55:40 AM

Found where is the problem. If i add

Code: [Select]

BATCh
DT,,0.001
PROP
END
and do one more loop for solution

Code: [Select]

BATCh
LOOP,last,1000
TIME
LOOP,equi,99
TANG,,1
NEXT,equi
NEXT,last
END
then i got the right result. That means load should increase gently.