For fixed geometry designs, you need to convert the design constraints into material
property limits using the Engineering Solver.
To use the performance index finder, you need to have a design with a free geometric
variable.
If there is no free variable, the design is a fixed geometry design, with a fixed
volume. In these situations, you need to convert the design constraints into
material property limits using the Engineering Solver. Use a
chart to select materials based on the properties you want to optimize.
For example, in a stiffness-limited design with no free variable (fixed volume), to
minimize mass and cost, create a chart of density (or mass per unit volume) vs.
price*density (or cost per unit density).
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Start the Engineering Solver. Select the required function, enter the
engineering requirements, and calculate values for Young’s modulus and yield
strength.
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Create a limit stage. Enter the values of Young’s modulus and yield strength
from the Engineering Solver as minimum values in the limit stage.
- This will filter out materials with values that do not meet these
criteria.
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Create a chart, and on the axes, plot the properties you want to optimize in
the design.
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- For example, for a stiffness-limited design with no free variable
(fixed volume), and minimizing mass and cost, plot density (or mass
per unit volume) vs. price*density (or cost per unit volume). On the
chart (below), the materials shown in gray failed the limit stage.
The orange line is a trade-off curve.
