Environmental Engineering Reference
In-Depth Information
Table 12.1
(continued)
Flexural strength
[MPa]
Flexural youngs modulus
[GPa]
Ratio
PE23
300
23
13.04
GRFP-M
80
7
11.43
GRFP-MW
120
12
10
GRFP-FM/FMU
160
15
10.67
NRFP
101
14.38
7.02
flexibility of the construction, rather than linking multiple rigid parts together, one
may cause a dramatic reduction in the total number of parts required to accomplish
a specific mechanical task. Reducing the amount of parts may decrease assembly
time and simplify manufacturing processes, which in turn may result in significant
cost reduction.
Another important benefit is that compliant mechanisms often show an
increased performance regarding reliability. This is due to the fact that they have
few or no hinges, comparable to conventional revolute or sliding joints. Thus, the
wear in these structures and the need for lubrication is very low. These are
valuable characteristics, especially for applications where mechanisms are either
difficult to access or operating in harsh environments, in which conventional joints
would rust and require significant maintenance.
Furthermore, one of the main advantages of compliant mechanisms is their
capacity to store energy in their deflected flexible members. If a compliant
mechanism is based on material with little creeping behaviour, it can store strain
energy over a longer time period and release it at wish at a later stage, or use it to
reset the mechanism to its original state again. But beyond that, it is also possible
to fine-tune the force-deflection relationships in the flexible structure to correlate
energy and motion and vice versa. The transmission ratio therein can be tailored to
suit specific functional needs with targeted amplification effects. For a given
energy input the mechanical response of compliant mechanisms can be customised
to achieve, for instance, either a maximum displacement (displacement multipli-
cation), or a maximum resulting force (force multiplication).
12.3 Biomimetic Approach
In the last decade, using nature as an inspirational source to solve technical
problems has become scientifically recognised. Through the evolutionary pressure
of natural selection on organisms to survive under particular boundary conditions,
highly-adapted systems have developed. In order to use such systems as role
models for technical applications a 'top-down approach' can be used to solve
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