Learning Forum

[Brian Lolley]

Hello, I have a new problem with my inflatable arch structure. The base of my structure causes an error as seen in figure 1 which is a Newton-Raphson force residual plot. However, if I apply a deflection limitation in the Z axis as seen in figure 2, the model runs which can be seen in figure 3. It should be noted that there are 24 straps leading to the structure which have been simply supported at their edges as seen in figure 4. I have checked my connections a multitude of times and I do not see any problems there. Does anyone know of common mistakes I might be making? 

Thanks,

Brian 

 

[Ashish Khemka]

Hi Brian,

Can you please share an exaggerated plot for deformation? What type of reult are you expecting and how the current boundary conditions are not helpful?

Regards,

Ashish Khemka

[Brian Lolley]

Ashish,

Here are a few images. When I exagerate deformation it appears that the base is having the same connection problems as mentioned previously, but the model is able to run. I am applying wind pressures from a 40 mph wind to the structure. The deformations, neglecting the connection issue, is what I am expecting; however, my professors want the model to be as close as possible to the real structure. So, I need to see the deflection in the base.

[Ashish Khemka]

Brian, can you please share the details of the connections?

Regards,

Ashish Khemka

[Brian Lolley]

Ashish, there are many connections. Here is how the front left section of the structure is connected at the base. The other three sections are connected in the exact same way. I still find it strange that the two connections in the back are not having the same issues. 

[Ashish Khemka]

Brian,

Which is the contact algorithm used by you?

Regards,

Ashish Khemka

[Brian Lolley]

Ashish, I see program controlled for Formulation under Advanced.