Compliant mechanisms gain at least some of their motion from flexible members. The combination of large-deflection beam analysis, kinematic motion analysis, and energy storage makes the analysis of compliant mechanisms difficult. The design of mechanisms often requires iteration between synthesis and analysis procedures. In general, the difficulty in analysis has limited the use of compliant mechanisms to applications where only simple functions and motions are required. The pseudo-rigid-body model concept promises to be the key to unifying the compliant and rigid-body mechanism theories. It simplifies compliant mechanism analysis by determining an equivalent rigid-body mechanism that accurately models the kinematic characteristics of a compliant mechanism. Once this model is obtained, many well known concepts from rigid-body mechanism theory become amenable for use to analyze and design compliant mechanisms. The pseudo-rigid-body-model concept is used to develop a loop-closure method for the analysis and synthesis of compliant mechanisms. The method allows compliant mechanisms to be designed for tasks that would have earlier been assumed to be unlikely, if not impossible, applications of compliant mechanisms.

Issue Section:
Research Papers
Topics:
Compliant mechanisms, Rigid-body mechanisms, Design, Kinematics, Deflection, Energy storage
1.
Ananthasuresh, G. K., Kota, S., and Gianchandani, Y., 1994, “A Methodical Approach to the Design of Compliant Micromechanisms,” Solid-State Sensor and Actuator Workshop, Hilton Head Island, SC, pp. 189–192.
2.
Bagci
 
C.
,
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Synthesis of Linkages to Generate Specified Histories of Forces and Torques—The Planar 4R Four-Bar Mechanism
,”
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227
–
236
.
3.
Burns, R. H., 1964, “The Kinetostatic Synthesis of Flexible Link Mechanisms,” Ph.D. Dissertation, Yale University.
4.
Burns, R. H., and Crossley, F. R. E., 1968, “Kinetostatic Synthesis of Flexible Link Mechanisms,” ASME Paper No. 68-Mech-36.
5.
Erdman, A. G., and Sandor, G. N., 1991, Mechanism Design: Analysis and Synthesis, Vol. 1, Second Edition, Prentice-Hall, Englewood Cliffs, NJ.
6.
Her, I., Midha, A., and Salamon, B. A., 1992, “A Methodology for Compliant Mechanisms Design: Part II—Shooting Method and Application,” Advances in Design Automation, D. A. Hoeltzel, ed., DE-Vol. 44-2, 18th ASME Design Automation Conference, pp. 39–45.
7.
Howell, L. L., 1993, “A Generalized Loop-Closure Theory for the Analysis and Synthesis of Compliant Mechanisms,” Ph.D. Dissertation, Purdue University.
8.
Howell
 
L. L.
, and
Midha
 
A.
,
1994
a, “
A Method for the Design of Compliant Mechanisms with Small-Length Flexural Pivots
,”
ASME JOURNAL OF MECHANICAL DESIGN
, Vol.
116
, No.
1
, pp.
280
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290
.
9.
Howell, L. L., and Midha, A., 1994b, “A Generalized Loop-Closure Theory for the Analysis and Synthesis of Compliant Mechanisms,” Machine Elements and Machine Dynamics, G. R. Pennock, ed., DE-Vol. 71, 23rd ASME Mechanisms Conference, pp. 491–500.
10.
Howell, L. L., Midha, A., and Norton, T. W., 1994, “Evaluation of Equivalent Spring Stiffness for Use in a Pseudo-Rigid-Body Model of Large-Deflection Compliant Mechanisms,” Mechanism Synthesis and Analysis, G. R. Pennock, ed., DE-Vol. 70, 23rd ASME Mechanisms Conference, pp. 405–412, and accepted for publication in ASME JOURNAL OF MECHANICAL DESIGN.
11.
Howell
 
L. L.
, and
Midha
 
A.
,
1995
, “
Parametric Deflection Approximations for End-Loaded, Large-Deflection Beams in Compliant Mechanisms
,”
ASME JOURNAL OF MECHANICAL DESIGN
, Vol.
117
, No.
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, pp.
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.
12.
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C.
, and
Roth
 
B.
,
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, “
Dimensional Synthesis of Closed-Loop Linkages to Match Force and Position Specifications
,”
ASME JOURNAL OF MECHANICAL DESIGN
, Vol.
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, No.
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13.
Jenuwine
 
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, and
Midha
 
A.
,
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, “
Synthesis of Single-Input and Multiple-Output Port Mechanisms with Springs for Specified Energy Absorption
,”
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, Vol.
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, No.
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, pp.
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–
943
.
14.
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15.
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,
Her
 
I.
, and
Salamon
 
B. A.
,
1992
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A Methodology for Compliant Mechanisms Design: Part I—Introduction and Large-Deflection Analysis
,”
Advances in Design Automation
, D. A. Hoeltzel, ed., DE-Vol.
44–2
, 18th ASME Design Automation Conference, pp.
29
–
38
.
16.
Norton, T. W., 1991, “On the Nomenclature and Classification, and Mobility of Compliant Mechanisms,” M.S. Thesis, Purdue University.
17.
Salamon, B. A., 1989, “Mechanical Advantage Aspects in Compliant Mechanisms Design,” M.S. Thesis, Purdue University.
18.
Sevak, N. M., and McLarnan, C. W., 1974, “Optimal Synthesis of Flexible Link Mechanisms with Large Static Deflections,” ASME Paper No. 74-DET-83.
19.
Shigley, J. E., and Uicker, J. J., 1995, Theory of Machines and Mechanisms, Second Edition, McGraw-Hill, New York, NY.
20.
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S. J.
, and
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T. E.
,
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,”
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, No.
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.
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