Applying non-linear forces on edges

[stults]

Hi everyone,
I am trying to run a COSMOSWorks static stress analysis of an aircraft wing with an elliptical lift distribution (greater lift near the root of the wing, and less at the tip). My lift distribution is defined by a 2-D curve, so I am applying the load at the aerodynamic center of the wing (approximately at the quarter-chord), rather than over the entire top surface.

I have created a split line at the quarter chord to split the top surface of the wing, and I am trying to apply my force along the line, but COSMOS does not allow me to use an equation to define the force if it is applied on an edge or line.

Do you know if there is a better way to apply the force so it realistically models the elliptical distribution? Would it be better to apply the load over the top surface of the wing so that it can vary with the equation? Does the nonlinear analysis option allow forces to change along a line?

I am new to COSMOS, and am using COSMOSWorks Advanced Professional 2008 SP 0.

Thanks,

Sara Stults

 

[cbrn]

Hi,
you can express a pressure as a function. The built-in function type in CW is expressed in quadratic form:
P = a*x^2+b*y^2+c*xy+d*x+e*y+f
so, by definition, an elliptical distribution IS possible. You just have to put a coordinate system with the correct orientation, and determine the "explicit" form of the equation of your ellipse.

Regards

 

[stults]

Thanks!

I ended up using several point loads along the line to approximate it for now, and I'm going to try using a quadratic equation to define the load to improve the results. I'm thinking of adding in another split line so that I have a thin surface along the line of aerodynamic center that I can apply my elliptical distribution on, or maybe modifying my equation to use 3-D data instead of 2-D data so I can apply it to the entire top surface.

Sara Stults