(ANSYS APDL STRUCTURAL) Conducting model analysis for a aeroplane wing (stationary) using brick element.

Question: This is a simple modal analysis of a air-plane wing. The wing is of uniform configuration along its length and its cross section area is defined to be a straight line and a spline as shown in the figure. It is held fixed at one end and hangs freely at other. The objective of the problem is to find the wings natural frequency and mode shape. The EX = 0.75E5, PRXY = 0.33 & Density = 2.79E-9. Assume the side of the wing is connected to the plane and completely fixed in all degrees, the wing is solid and Pre - processor > material properties are constant and isotropic.

Preference > structural > ok

Pre-processor >element type > add/edit/delete > add > solid > brick 8 node 185 > apply > now select "not solved" > mesh face 200 > ok.

NOTE: We take two elements (solid 185 & mesh 200)

Pre - processor > element type > add/edit/delete > mesh 200 > options > K1 = Quad 4 node > ok > close.

Pre - processor > material properties> material model > structural > linear > elastic > isotropic > EX = 0.75E5, PRXY = 0.33.

Pre - processor > material properties> material model > structural > density > density = 2.79E-9 > materials > exit.

Pre - processor > modelling > create > key points > in active cs > (follow the bellow table)

Key point No	X - location	Y - location	Z - location
1	0	0	0	Apply
2	2	0	0	Apply
3	2.3	0.2	0	Apply
4	1.9	0.45	0	Apply
5	1	0.25	0	Ok

Pre - processor > modelling > create > lines > lines > straight lines > join (key point 1 and key point 2)

Pre - processor > modelling > create > lines > spline > spline through key points > select key points (2,3,4,5,1) > ok.

Pre - processor > modelling > create > area > arbitrary > by lines > select the spline and the line 1-2 > ok.

Pre - processor > modelling > operate > extrude > area > along normal direction > select area > ok > length of extrusion = 10 > ok.

Pre - processor > meshing > mesh tool > size control > line set > select all line (pick all) > ok > element edge length = 0.1 >  ok.

Pre - processor > meshing > mesh tool > element attributes > set > convert "element type number = mesh 200" > ok > in mesh convert the type to area > select mesh > select a side of the wing > ok.

Pre - processor > meshing > mesh tool > element attributes > set > convert "element type number = solid 185" > ok > in mesh convert the type to volume > select hex > select sweep > select mesh > select the body of  the wing > ok.

Pre - processor > loads > define loads > apply > structural > displacement > on area > select the side area  of the wing > ok > all "DOF" > ok.

Solution > solve > current LS > ok > yes > close.

Solution > analysis type > new analysis > select "modal" > ok.

Solution > analysis type > analysis options > number of mode shapes to extract = 5 & number of mode shapes to expand = 5 > ok.

NOTE: Number of mode shapes is found by the formula [N = (n-1)], where N = number of mode shapes, n = degree of freedom.

Solution > solve > current LS > ok > yes > close.

General post processor > read results > by pick > select one from the five (i.e. 3rd )> read.

General post processor > Plot results > contour plot > nodal solution > select "DOF" solution > displacement vector sum.