OS-E: 0805 Two-dimensional Michell-truss
The two-dimensional Michell-truss is an optimal topology structure generated under bending.
Model Files
Model Description
The design space for this problem consists of a rectangle with a single vertical load at the free end. A circular cut-out is constrained in all translational degrees-of-freedom on the inside free edge.
This is a compliance minimization problem with a material volume fraction constraint of 20%. CQUAD4 (4-noded isoparametric) elements are used in a design space defined by a rectangular region with an aspect ratio approximately equal to one quarter of the short edge located closer to the edge away from the load.
DESGLB = 2
$
SUBCASE 1
SPC = 1
LOAD = 2
DESOBJ = 1
BEGIN BULK
$
DRESP1,1,comp,COMP
DRESP1,2,volfrac,VOLFRAC
DCONSTR,2,2,,0.2

Figure 1. Finite Element Mesh of the Design Space for the Two-dimensional Michell-truss
This example is analyzed using the one-file setup with the file,
michell.fem. The OptiStruct
batch job is submitted using the command shell script, % optistruct
michell
.
Results

Figure 2. Contour Plot of Density Results for the Two-dimensional Michell-truss