Print Email Facebook Twitter Design and optimization of a general planar zero free length spring Title Design and optimization of a general planar zero free length spring Author Delissen, A.A.T.M. (TU Delft Computational Design and Mechanics) Radaelli, G. (TU Delft Mechatronic Systems Design) Herder, J.L. (TU Delft Mechatronic Systems Design) Date 2017 Abstract A zero free length (ZFL) spring is a spring with special properties, which is commonly used in static balancing. Existing methods to create ZFL springs all have their specific drawbacks, which rises to the need of a new method to create such a spring. A method is proposed to design planar ZFL springs with specified stiffness (250–750 N/m) within a certain range (up to 20 mm of displacement). Geometric non-linearities of a curved leaf spring are exploited by changing its shape. The shape is determined by a non-linear least squares algorithm, minimizing the force residuals from a non-linear numerical analysis. Constraints are introduced to help in preventing the spring from intersecting itself during deformation. For three types of springs with different boundary conditions, designs are found with characteristic shapes and maximum force errors less than 1%. A trend is observed between spring size, maximum stress and desired stiffness. New type of ZFL springs can now be designed, which can not only be used in existing applications, but also enables the use of ZFL springs in micro mechanisms. Subject Curved flexureDesired force-displacementIdeal springNull-length springShape optimizationZero free length spring To reference this document use: http://resolver.tudelft.nl/uuid:61707111-8d78-448d-b502-71a7c66b9887 DOI https://doi.org/10.1016/j.mechmachtheory.2017.07.002 Embargo date 2019-07-11 ISSN 0094-114X Source Mechanism and Machine Theory, 117, 56-77 Bibliographical note Accepted Author Manuscript Part of collection Institutional Repository Document type journal article Rights © 2017 A.A.T.M. Delissen, G. Radaelli, J.L. Herder Files PDF Paper_ZFLS_MECHMT_R2.pdf 2.7 MB Close viewer /islandora/object/uuid:61707111-8d78-448d-b502-71a7c66b9887/datastream/OBJ/view