tension only 1D element

Simon Križnik

Hi,

 

how to set up tension only (no compression, bending and torsion) 1D element in Radioss?

I have tried with truss and spring elements. However, truss elements have axial compression stiffness and there is discrepancy in the plots, possibly because of geometric non-linearity.

<?xml version="1.0" encoding="UTF-8"?>

compression (truss in blue, spring in red color)

<?xml version="1.0" encoding="UTF-8"?>

tension

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Altair Forum User

hello!

i haven't opened your model.

at first, i don't now about altair, but it doesn't recomend to use no tension/no compression to beam/truss elements in abaqus.

i'm looking for your model and will give some advice, but i'm just newbie in altair solvers.

Altair Forum User

it's interesting, becouse i thought if i splite truss to 2 element i will have no compression force. i'm confuse, but it doesn't work in radioss...

Simon Križnik

Hi Mrt,

 

thanks for your input.

 

My observation is if the force or displacement is applied coaxial to the truss/beam elements they will not buckle in compression, since FEA does not model material or geometry imperfections that would buckle the structure in reality.

 

Altair Forum User

but spring works well, why don't u use it?

Altair Forum User

Yeah, nonlinear springs. But, input is tricky,

Simon Križnik

Thanks for suggestions,

 

I will use one degree of freedom spring element (TYPE4) with nonlinearity defined through force-displacement curve.