C haPter 5 Material Property Charts and their Uses
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criterion of excellence, whichever is required. You could simply
choose the top-ranked candidate, but what hidden weaknesses
might it have? What is its reputation? Has it a good track record? To
proceed further, we seek a detailed profile of each: its documentation
(Figure 5.8, bottom).
What form does documentation take? Typically it is descriptive,
graphical, or pictorial: case studies of previous uses of the material,
details of its corrosion behavior in particular environments, of its
availability and pricing, warnings of its environmental impact or
toxicity. Such information is found in handbooks, suppliers’ data
sheets, CD-based data sources, and high-quality Websites. Documentation helps narrow the shortlist to a final choice, allowing
a definitive match to be made between design requirements and
material attributes.
Why are all these steps necessary? Without screening and ranking,
the candidate pool is enormous and the volume of documentation
is overwhelming. Dipping into it, hoping to stumble on a good
material, gets you nowhere. But once a small number of potential
candidates have been identified by the screening/ranking steps,
detailed documentation can be sought for these few alone, and the
task becomes viable.
5.3 Plotting liMits anD inDiCes
on Charts
screening: Constraints on Charts
Any design imposes certain nonnegotiable demands (“constraints”)
on the material of which it is made. These limits can be plotted
as horizontal or vertical lines on material property charts, as illustrated in Figure 5.9. The figure shows a schematic of the E–relative
cost chart shown earlier. We suppose that the design imposes limits
on these of E > 10 GPa and relative cost <3, shown in the figure.
All materials in the window defined by the limits, labeled “Search
region,” meet both constraints.
Charts exist for many properties; others can be generated using
the CES software.
2 They allow limits to be imposed on other
properties.
2 The CES Edu software (www.Grantadesign.com). It was used to create all the property charts shown
in this and other chapters.
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criterion of excellence, whichever is required. You could simply
choose the top-ranked candidate, but what hidden weaknesses
might it have? What is its reputation? Has it a good track record? To
proceed further, we seek a detailed profile of each: its documentation
(Figure 5.8, bottom).
What form does documentation take? Typically it is descriptive,
graphical, or pictorial: case studies of previous uses of the material,
details of its corrosion behavior in particular environments, of its
availability and pricing, warnings of its environmental impact or
toxicity. Such information is found in handbooks, suppliers’ data
sheets, CD-based data sources, and high-quality Websites. Documentation helps narrow the shortlist to a final choice, allowing
a definitive match to be made between design requirements and
material attributes.
Why are all these steps necessary? Without screening and ranking,
the candidate pool is enormous and the volume of documentation
is overwhelming. Dipping into it, hoping to stumble on a good
material, gets you nowhere. But once a small number of potential
candidates have been identified by the screening/ranking steps,
detailed documentation can be sought for these few alone, and the
task becomes viable.
5.3 Plotting liMits anD inDiCes
on Charts
screening: Constraints on Charts
Any design imposes certain nonnegotiable demands (“constraints”)
on the material of which it is made. These limits can be plotted
as horizontal or vertical lines on material property charts, as illustrated in Figure 5.9. The figure shows a schematic of the E–relative
cost chart shown earlier. We suppose that the design imposes limits
on these of E > 10 GPa and relative cost <3, shown in the figure.
All materials in the window defined by the limits, labeled “Search
region,” meet both constraints.
Charts exist for many properties; others can be generated using
the CES software.
2 They allow limits to be imposed on other
properties.
2 The CES Edu software (www.Grantadesign.com). It was used to create all the property charts shown
in this and other chapters.