hassalthoff
Mechanical
We are trying to extract the CROSS SECTIONAL properties about a center axis of an arbitrary hollow shape with shell element laminate. We want the stiffness properties as if looking down the center axis (like looking down a wing), not the properties on the outside face (on top of the wing). An example of this would be a hollow rectangle with stiff top and bottom of thickness A, and flexible sides of thickness B...We would want the properties EIxx, EIyy, shear centers, etc about the plane perpendicular to the center axis. (See attachment)
The current femap "tools->section properties" function only looks at the surface/surface of the elements you are asking about. In other words, it would take the stiffness of the sides of the box, not the cross section (through-thickness direction).
The current femap sectional properties tool only considers single material or standard sized "cross sections", I-beams, etc. We do not want this for 3 reasons: 1) we are modeling multiple materials and 2) our shape is arbitrary and varies along the length of the part and 3) we want to be able to select our already-modeled part and have the sectional properties be calculated about a given axis.
Our FEMAP rep says that the functionality of what we are trying to do is not in FEMAP. At his suggestion, I am downloading a trial version of VABS that calculate the cross sectional stiffnesses, but it would be extremely useful and well-used feature in FEMAP.
In ANSYS, one can define an arbitrary cross section, with a through-thickness mesh of laminate, but one still has to create the section independent of your model (using secwrite/secread commands for arbitrary shapes of laminate...see chapter 16 of their apdl help). I only list that to see if it might draw a parallel to FEMAP.
Grabbing cross sectional mass and stiffnesses is a quite common need, so I am wondering...Has anyone had to grab the cross-sectional mass and stiffness before and what did you do? Has anyone written a script that will compute the cross sectional properties of a shell laminate, ideally directly off a selected set of elements?
Thanks!
The current femap "tools->section properties" function only looks at the surface/surface of the elements you are asking about. In other words, it would take the stiffness of the sides of the box, not the cross section (through-thickness direction).
The current femap sectional properties tool only considers single material or standard sized "cross sections", I-beams, etc. We do not want this for 3 reasons: 1) we are modeling multiple materials and 2) our shape is arbitrary and varies along the length of the part and 3) we want to be able to select our already-modeled part and have the sectional properties be calculated about a given axis.
Our FEMAP rep says that the functionality of what we are trying to do is not in FEMAP. At his suggestion, I am downloading a trial version of VABS that calculate the cross sectional stiffnesses, but it would be extremely useful and well-used feature in FEMAP.
In ANSYS, one can define an arbitrary cross section, with a through-thickness mesh of laminate, but one still has to create the section independent of your model (using secwrite/secread commands for arbitrary shapes of laminate...see chapter 16 of their apdl help). I only list that to see if it might draw a parallel to FEMAP.
Grabbing cross sectional mass and stiffnesses is a quite common need, so I am wondering...Has anyone had to grab the cross-sectional mass and stiffness before and what did you do? Has anyone written a script that will compute the cross sectional properties of a shell laminate, ideally directly off a selected set of elements?
Thanks!
