Box with Nested Webs

Box example with nested webs defined directly in the XML input.

Overview

Figure 19 Cross section of the box beam with nested internal webs.

This example is a closed box cross-section built entirely from <baseline> elements in box.xml, with no <include> files. The outer contour (bsl_all) is a rectangle spanning \(a_2=1.618\) in in width and \(a_3=1.0\) in in height. Six internal webs (lweb1–lweb6) are then added as single <line> baselines, each given by a start point and a departure angle.

The webs are nested rather than all attached to the outer contour directly: web1 depends only on main, but web2 depends on main,web1, web3 on main,web1,web2, and so on through web6, which depends on all five preceding webs. Each web line is trimmed against every component it depends on, so this chain of depend lists builds up the stepped, nested set of internal compartments visible on the right side of Cross section of the box beam with nested internal webs. (a single full-height web at \(x=-0.191\), followed by progressively smaller nested pockets).

Every component uses the same material and layup, listed in Material properties and Layups.

Table 13 Material properties

Name	Density	\(E_{1}\)	\(E_2=E_3\)	\(G_{12}=G_{13}\)	\(\nu_{12}=\nu_{13}\)
	\(\mathrm{lb\cdot sec^2/in^4}\)	\(\mathrm{psi}\)	\(\mathrm{psi}\)	\(\mathrm{psi}\)
mtr_lamina	10	4	5	6	0.40

Table 14 Layups

Name	Layer	Lamina	Ply thickness	Orientation
			\(\mathrm{in}\)	\(\circ\)
layup1	1	la_mtr_lamina_0.01	0.02	0
layup1	2	la_mtr_lamina_0.01	0.02	90

The global mesh size is \(0.01\) in, with quadratic (default) triangular elements.

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Input

• box.xml

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Run the example

prevabs -i box.xml --hm

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Output

Figure 20 Cross section viewed in gmsh.

• box.png