## Forum

### Application of GEBT to overhanging simply supported beam

1. Dear all,

I'm trying to implement GEBT for an over hanging simply supported beam. When I'm trying to apply I'm getting below error as shown
I'm expecting the error can be from the boundary conditions. Still I' unable to figure out the error. I'm attaching the input please go through the code and help me in solving the problem.
The problem has
point 1 as the free end
point 2 as the hinged support
point 4 as the roller support
point 5 as the free end
Applying boundary conditions is still not clear, it would be great help if you could share some examples for overhanging beam.

Regards
Shiva Harsh
IISc, Bangalore

2. Hi Shiva,

I agree with you that the problem could be in the boundary conditions. To be specific, I think your definition of the "roller support" at Point 4 is not correct. I checked the GEBT manual, it is said that the dof_i in the ncond_pt block should be "integers with values ranging from 1 to 12". However, in your input file, these are "2 3 4 0 0 0".

Qi

3. Dear sir,

Thank you for the reply. I tried with finite boundary condition values. Still the error persists. As mentioned in the manual, 1 and 5 are boundary points six boundary conditions has to be prescribed. So for

point 1 and 5, I had given Forces and moments has zero. (free ends-over hanging)

Point 2 is hinged, so u1=u2=u3=M1=M2=M3=0

point 4 is Roller so u2=u3=M1=M2=M3=0 and F1=0

With this also the error persists. I'm attaching the modified input file. Please find the attachment and clear my query.

Thanks & Regards

Shiva Harsh

4. Hi Shiva,

I checked you file, and it seems at point 3, you put value 100 to bc#9 but control parameters 1s to bc#10.

Hope that helps.

Ning

5. Hi sir,

Thank for your response. I think the value 100 for bc#10 corresponds to the moment M1. I had given bc#9 because I want to give F3.

Also I tried running by changing the value but the error still persists.

Thanks & Regards

Shiva Harsh

6. Dear all,

I took the help of the examples for (GEBT) and tried to implement to the overhanging beam,

The boundary conditions I used are

#1 and #5

Free end So F1=F2=F3=M1=M2=M3=0 which implies 7 8 9 10 11 12 are zeros

#2 is roller support

u2=u3=M1=M2=M3=theta1=0 which implies 2 3 4 10 11 12 are zeros

F1=F2=M1=M2=M3=0 and F3=-100 which implies 7 8 10 11 12 are zeros and 9=-100

#4 is Hinge support

u1=u2=u3=M1=M2=M3=0 which implies 1 2 3 10 11 12 are zeros

Note: Theta1=0 is zero i imposed externally as there is load only in 3 direction & there wont be any twist. Correct me if I'm wrong.

The input file is running but the I'm unable to capture the reaction forces at the roller and hinge support. I'm attaching the input file for your reference. I need this problem because I'm using this model for validation in my ME thesis.

In the results I'm getting the value of reactions as the zero's but the value is nonzero just right to the roller support and left to the hinged support. The value is 500N as the load applied for this input is 1000 in 3 direction. The values are right but at the supports the value is zero,What could be the reason.

7. 