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HiFirstly, it is important to ensure that the model has been set up correctly with the appropriate reference planes and coordinate systems. If the reference planes are not set up correctly, this could cause issues with the offsets and other calculations.
I’m currently trying to size a single sided Orthogrid panel which has been discretely modelled with BAR and QUADS. I’m using a ‘One stack unstiffened’ concept for the plate and a ‘Web Beam’ concept for the stiffener. At this moment in time I’m not using Stringer Segments, as I believe the preferred process is to size a panel using Plates and Bars first, and then use Stringer Segments as a final check as this is a quicker way of doing things.
The issues that I’m having relates to defining the BAR ‘reference plane’ and how this calculates the Offset within the BAR element when it updates the FEM. At this moment I’m trying to size a single sided machined stiffened panel, hence as the elements are modelled on the plate centroid then I’m using either the ‘Top’ or ‘Bottom’ reference plane, depending on which side I’m offsetting the stiffeners. The first issue is that the ‘Top’ reference plane does not seem to change the BAR offset during the HyperFEA loops, whereas the ‘Bottom’ reference plane does. Is there a reason why I can only Offset the BAR in one direction?
The next issue is regarding to the BAR Offsets during the HyperFEA process, as it looks like the full stiffener height is being used as the BAR offset instead of using ½ the stiffener height during the FEM update. This would produce an incorrect panel stiffness/frequency and therefore an incorrect load redistribution. Is there a reason why the BAR offsets are set to the full height of the stiffener and is there a setting to correct this? This does not seem to happen when using stringer segment.
Regards
Gawain
In summary, wing tip optimization can be achieved by using an optimization algorithm that searches for the best wing design while taking into account factors such as global stiffness, wing tip deflection, twist, and spanwise distortion. An object model can be used to represent the wing in 3D space and calculate its deformation under different loading conditions. HyperFEA can be used for finite element analysis and setting limits on wing tip displacement, but it may not directly optimize for smooth spanwise distortion. Multi-objective optimization algorithms can be used to simultaneously optimize for multiple objectives and achieve the best possible wing design for your application.
how to realize wing tip optimization ? I mean to optimize the global stiffness of wing by limiting wing tip deflection and twist, and to make the wing spanwise distortion smooth.
by using Object Model? if how?
I know wing tip displacement limits can be given when running hyperFEA, but I am not sure whether the spanwise distortion is smooth.
