TY - GEN
T1 - A STRESS-DEFLECTION MODEL FOR FIXED-CLAMPED FLEXURES USING A PSEUDO RIGID BODY APPROACH
AU - Huxman, Connor
AU - Butler, Jared
N1 - Funding Information:
The authors are grateful for support from the Diefenderfer Graduate Fellowship in Entrepreneurship at The Pennsylvania State University, which has funded in large part this work. The authors are also thankful for the work of Kaylie Barber who assisted greatly in the manufacturing of test specimens.
Publisher Copyright:
Copyright © 2022 by ASME.
PY - 2022
Y1 - 2022
N2 - Fixed-clamped flexures are one common component of compliant mechanisms which remain difficult to design due to their unique force- and stress-deflection response profiles. In this work, a stress-deflection model for fixed-clamped flexures is proposed that utilizes a modified pseudo rigid body model. Special analysis is carried out on the characteristic radius factor, a parameter to which model accuracy is particularly sensitive. Effects of both deflection magnitude and flexure geometry on this parameter are explored and considerations for optimal parameter selection are included. Finite element analysis demonstrates that the model is able to predict the vertical applied force, horizontal reaction force, and maximum von Mises stress with a maximum percent error less than 3.5% at yield for a range of steel flexure topologies. Using the model to predict behavior of flexible polypropylene flexures undergoing larger deflections, the model has a maximum error between 4 - 14% using static model parameters, compared to 74 - 96% using the small deflection equations. The distinct combination of axial and bending stresses experienced in fixed-clamped flexures has made mechanisms which use these members challenging to design. This work provides a model that designers, engineers, and researchers can draw from to understand stress profiles present in these flexible members.
AB - Fixed-clamped flexures are one common component of compliant mechanisms which remain difficult to design due to their unique force- and stress-deflection response profiles. In this work, a stress-deflection model for fixed-clamped flexures is proposed that utilizes a modified pseudo rigid body model. Special analysis is carried out on the characteristic radius factor, a parameter to which model accuracy is particularly sensitive. Effects of both deflection magnitude and flexure geometry on this parameter are explored and considerations for optimal parameter selection are included. Finite element analysis demonstrates that the model is able to predict the vertical applied force, horizontal reaction force, and maximum von Mises stress with a maximum percent error less than 3.5% at yield for a range of steel flexure topologies. Using the model to predict behavior of flexible polypropylene flexures undergoing larger deflections, the model has a maximum error between 4 - 14% using static model parameters, compared to 74 - 96% using the small deflection equations. The distinct combination of axial and bending stresses experienced in fixed-clamped flexures has made mechanisms which use these members challenging to design. This work provides a model that designers, engineers, and researchers can draw from to understand stress profiles present in these flexible members.
UR - http://www.scopus.com/inward/record.url?scp=85142471091&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85142471091&partnerID=8YFLogxK
U2 - 10.1115/DETC2022-89983
DO - 10.1115/DETC2022-89983
M3 - Conference contribution
AN - SCOPUS:85142471091
T3 - Proceedings of the ASME Design Engineering Technical Conference
BT - 46th Mechanisms and Robotics Conference (MR)
PB - American Society of Mechanical Engineers (ASME)
T2 - ASME 2022 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, IDETC-CIE 2022
Y2 - 14 August 2022 through 17 August 2022
ER -