Compliance Based Characterization of Spherical Flexure Hinges for Spatial Compliant Mechanisms

Rad, Farid Parvari; Berselli, Giovanni; Vertechy, Rocco; Castelli, Vincenzo Parenti

doi:10.1007/978-3-319-07058-2_45

Cited by 3 publications

(3 citation statements)

References 9 publications

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“…The straightaxis flexure hinges quasi-static behavior has mainly been characterized by means of analytical and numerical methods, including the analytical compliance/stiffness matrix approach and the finite element technique - [4], the extended compliance matrix procedure - [5] and the discrete-beam transfer matrix method - [6]. Expanding the deformation capabilities of straight-axis, 1D hinge configurations are the two-dimensional (2D) flexible hinges, which either are made of a single segment or combine segments with planar-curve longitudinal axes that may include straight-axis segments, as studied in [4] and [17][18][19][20][21][22][23][24], for instance. Further enhancing the motion spectrum necessary in mechanisms for precision positioning and manipulation are the serial flexible hinges of 3D configuration, such as those presented in [25,26] -Fig.…”

Section: Introductionmentioning

confidence: 99%

High-flexibility three-dimensional serial folded hinges

LOBONTIU,

MOSES,

HUNTER

2024

RJTS-AM

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A new three-dimensional flexible hinge capable of large, linear-domain displacements is proposed for extended spatial workspace mechanisms. The hinge structure is compact and modular consisting of a large number of circular- and straight-axis segments connected in series and disposed in two parallel planes in a folded manner. The analytical, linear-model compliance matrix, which is necessary in direct/inverse kinematics and controls analysis, is derived based on simplified hinge geometry and small-deformation theory. The compliance model is accurate, as demonstrated by finite element simulation and experimental testing of a prototype. The compliance model is also utilized to determine the hinge piston-motion stiffness and the static response of several hinges connected in series. Another analytical compliance model is formulated to predict the hinge maximum loads and displacements in terms of allowable stresses. The mathematical models are further utilized to comprehensively investigate the influence of geometric parameters on the hinge performance.

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Section: Introductionmentioning

confidence: 99%

High-flexibility three-dimensional serial folded hinges

LOBONTIU,

MOSES,

HUNTER

2024

RJTS-AM

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“…Efforts have been made in both the characterization as in the design and optimization of spatial compliant mechanisms for the sake of advancing their applicability as full devices Supported by NWO (P16-05: Shell Skeletons) or as components. In flexures, which are flexible elements widely used for precision mechanisms, there are plenty of examples of spatial mechanisms [6,10] and established design principles exist [4,12].…”

Section: Introductionmentioning

confidence: 99%

Asymmetric Spatial Beams with Symmetric Kinetostatic Behaviour

Nobaveh

Radaelli

Herder

2020

ROMANSY 23 - Robot Design, Dynamics and Control

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A method to achieve symmetric kinetostatic behaviour in an extensive working range at the endpoint of an asymmetric spatial beam, using cross-section optimization, is presented. The objective function of the optimization is defined as expanding the beam working range to the desired region, simultaneously maximizing symmetric behaviour in it. To reach this goal, a beam with predefined spatial global shape and an 'I' cross-section selected. The cross-sectional dimensions throughout the beam are used as input values for the optimization. The endpoint displacements under symmetric loadings are attained using a nonlinear co-rotational beam element based on the Euler-Bernoulli beam formulation. The optimized beams are compared to a circular cross-section beam with the same global shape to show the efficacy of the method. Isoforce diagrams are investigated for the optimized beams to show the symmetry behaviour of the beam endpoint and the effect of changing different parameters in cross-sectional optimization is discussed.

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“…They are used in industrial or space applications, where high reliability, accuracy, and demanding requirements to contamination apply. Further advantages are, e.g., no need for assembly due to single-piece manufacturing, no friction losses, no need for lubrication due to lack of joints, and no wear by erosion due to lack of physical contact between kinematic pairs [2,3]. In space applications, flexible hinges are most commonly used in instrument mechanisms, e.g., for precise rotation of mirrors in a limited angular range, but also for the deployment of appendages and deployable booms, as so called collapsible flexible hinges.…”

Section: Introductionmentioning

confidence: 99%

Material Characterization of AISI 316L Flexure Pivot Bearings Fabricated by Additive Manufacturing

et al. 2019

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Recently, additive manufacturing (AM) by laser metal deposition (LMD) has become a key technology for fabricating highly complex parts without any support structures. Compared to the well-known powder bed fusion process, LMD enhances manufacturing possibilities to overcome AM-specific challenges such as process inherent porosity, minor build rates, and limited part size. Moreover, the advantages aforementioned combined with conventional machining enable novel manufacturing approaches in various fields of applications. Within this contribution, the additive manufacturing of filigree flexure pivots using 316L-Si by means of LMD with powder is presented. Frictionless flexure pivot bearings are used in space mechanisms that require high reliability, accuracy, and technical cleanliness. As a contribution to part qualification, the manufacturing process, powder material, and fabricated specimens were investigated in a comprehensive manner. Due to its major impact on the process, the chemical powder composition was characterized in detail by energy dispersive X-ray spectroscopy (EDX) and inductively coupled plasma optical emission spectrometry (ICP-OES). Moreover, a profound characterization of the powder morphology and flowability was carried out using scanning electron microscopy (SEM) and novel rheological investigation techniques. Furthermore, quantitative image analysis, mechanical testing, laser scanning microscopy, and 3D shape measurement of manufactured specimens were conducted. As a result, the gained knowledge was applied for the AM-specific redesign of the flexure pivot. Finally, a qualified flexure pivot has been manufactured in a hybrid manner to subsequently ensure its long-term durability in a lifetime test bench.

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Compliance Based Characterization of Spherical Flexure Hinges for Spatial Compliant Mechanisms

Cited by 3 publications

References 9 publications

High-flexibility three-dimensional serial folded hinges

High-flexibility three-dimensional serial folded hinges

Asymmetric Spatial Beams with Symmetric Kinetostatic Behaviour

Material Characterization of AISI 316L Flexure Pivot Bearings Fabricated by Additive Manufacturing

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