Variable Stiffness Design and Analysis of Flexure Hinge Based on ID-LEJ

2021 ◽  
Author(s):  
Yanlin Li ◽  
Lifang Qiu ◽  
Kang Zhou ◽  
Chongxiang Li
Keyword(s):  
Compliant Mechanisms ◽  
Rapid Development ◽  
Variable Stiffness ◽  
Flexure Hinge ◽  
Element Analysis ◽  
Bending Performance ◽  
Stiffness Design ◽  
Bending Capacity ◽  
Flexible Mechanism ◽  
Asymmetrically Distributed

Abstract In recent years, compliant mechanisms have attracted more and more attention of scholars at home and abroad, and achieved rapid development. The introduction of flexible variable stiffness design in flexible mechanism can not only improve the safety of human-computer interaction, but also improve the adaptability of the machine. Because the ID-LEJ (Inside-Deployed Lamina Emergent Joint) is a kind of LEMs and has very good bending performance. In this paper, the rotary ID-LEJ flexure hinge is proposed based on ID-LEJ hinge, to maximize the bending capacity of the hinge. In order to realize variable stiffness of rotary ID-LEJ, four sliders are arranged in the rotary ID-LEJ to change the stiffness of the hinge. The variable stiffness of the hinge is analyzed by Equivalent system and Finite element analysis. When the slider is symmetrically divided (yl1=yl2=yr1=yr2) the bending equivalent constant of the variable stiffness hinge varies continuously from 30.8 n · mm / rad ∼ 38.2n · mm / rad. And when the slider is asymmetrically distributed (yl1=yl2≠yr1=yr2) The bending equivalent constant of the variable stiffness hinge varies continuously from 30.8n · mm / rad to 34.2 · mm / rad. The results show that the variable stiffness performance is very flexible and stable.

Design and Analysis of a Contact-Aided Variable Stiffness Flexure Hinge (CVSFH)

2021 ◽  
Author(s):  
Shenyuan Dai ◽  
Lifang Qiu ◽  
Qichao Chen ◽  
Yanlin Li
Keyword(s):  
Contact Interaction ◽  
Compliant Mechanisms ◽  
Rectangular Cross Section ◽  
Variable Stiffness ◽  
Theoretical Equation ◽  
Flexure Hinge ◽  
Element Analysis ◽  
Equivalent Mechanical Model ◽  
Different Dimensions ◽  
Motion Characteristics

Abstract Flexure hinges are the basis of compliant mechanisms. The stiffness is one of the important indexes to evaluate the performance of a flexure hinge, and the rotation angle when the stiffness changes affects its motion characteristics. Thus, based on the constant rectangular cross-section flexure hinge and contact interaction, this paper proposed a contact-aided variable stiffness flexure hinge (CVSFH). With the deformation under an external load, the contact interaction with different parts of the CVSFH itself can achieve the purpose of variable stiffness. The equivalent mechanical model is built and the theoretical equation of the stiffness is given. CVSFHs with different dimensions are designed, and a finite element analysis (FEA) is done. The FEA results of the design examples are coincide with the theoretical results, which verifies the feasibility of the design and the correctness of the theoretical equation.

scholarly journals Multi-objective optimization of a type of ellipse-parabola shaped superelastic flexure hinge

2016 ◽  
Vol 7 (1) ◽  
pp. 127-134 ◽  
Author(s):  
Zhijiang Du ◽  
Miao Yang ◽  
Wei Dong
Keyword(s):  
Compliant Mechanisms ◽  
Pareto Frontier ◽  
Flexure Hinge ◽  
Multi Objective Optimization ◽  
Nsga Ii ◽  
Element Analysis ◽  
Multi Objective ◽  
Flexure Hinges ◽  
Static Responses ◽  
Motion Range

Abstract. Flexure hinges made of superelastic materials is a promising candidate to enhance the movability of compliant mechanisms. In this paper, we focus on the multi-objective optimization of a type of ellipse-parabola shaped superelastic flexure hinge. The objective is to determine a set of optimal geometric parameters that maximizes the motion range and the relative compliance of the flexure hinge and minimizes the relative rotation error during the deformation as well. Firstly, the paper presents a new type of ellipse-parabola shaped flexure hinge which is constructed by an ellipse arc and a parabola curve. Then, the static responses of superelastic flexure hinges are solved via non-prismatic beam elements derived by the co-rotational approach. Finite element analysis (FEA) and experiment tests are performed to verify the modeling method. Finally, a multi-objective optimization is performed and the Pareto frontier is found via the NSGA-II algorithm.

scholarly journals Investigation of Circular Flexural Hinge Used in Compliant Mechanism Using FEA Tool.

2016 ◽  
Vol 3 (1) ◽  
pp. 34-42
Author(s):  
M. M. Sawant ◽  
P. R. Anerao
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Life ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Flexure Hinge ◽  
Experimental Setup ◽  
Element Analysis ◽  
Flexural Hinges ◽  
Improve Fatigue

To reduce fatigue failure of compliant mechanism, it is necessary to design and analyze the flexure hinge parametrically. A methodology to design a flexural hinges for compliant mechanism is proposed in this paper to improve fatigue life. Results obtained by finite element analysis shows that used design equations are reliable and easier to be used in the design of such proportion flexural hinges. The proposed analytical model gives a new viewpoint on the design of circular flexure hinge based compliant mechanisms. Circular flexural joint was manufactured by using Al 6061 T6 material and experimental setup is developed to test this flexural hinge. Results obtained by FEA were found to be in good correlation with experimental results. The variation in the results can be attributed to variation in properties of material, actual dimensions of setup etc.

A Large-Deflection Annulus-Shape Flexure Hinge Based on Curved Beams

2008 ◽  
Author(s):  
Shanshan Zhao ◽  
Shusheng Bi ◽  
Jingjun Yu ◽  
Minglei Sun ◽  
Guanghua Zhong
Keyword(s):  
Large Deflection ◽  
Compliant Mechanisms ◽  
Accurate Method ◽  
Flexure Hinge ◽  
Curved Beam ◽  
Curved Beams ◽  
Element Analysis ◽  
Rigid Body Model ◽  
Compliant Joint ◽  
Design Tradeoffs

A curved flexure element such as an initially-curved beam can deflect largely and facilely. Using curved flexure elements in compliant mechanisms allows the mechanism to move a longer distance or undergo a larger rotation angle stroke than using conventional notch flexures. This paper presents a novel large-deflection annulus-shaped flexure hinge covering multiple curved-beam flexure elements. It has been shown that geometric symmetry in the constraint arrangement relaxes some of the design tradeoffs, resulting in some improved performances of the flexure hinge. Additional fixed RCM characteristic of isosceles-trapezoidal flexure modules existed in this compliant joint further improve its accuracy. A master-motion pseudo-rigid-body model provides a simple and accurate method to analyze the force-deflection behavior of this new rotary flexure hinge. The accuracy of the model is verified by comparing outcomes to non-linear finite element analysis. The result shows the proposed rotary flexure hinge has a large stroke angle, a low axial and radial stiffness.

Optimal Structural Design of Micro-Motion Stage with Stiffness Constraints Using Topology and Sizing Optimization Method

2016 ◽  
Vol 679 ◽  
pp. 55-58
Author(s):  
You Dun Bai ◽  
Zhi Jun Yang ◽  
Xin Chen ◽  
Meng Wang
Keyword(s):  
Compliant Mechanisms ◽  
Optimization Methods ◽  
Flexure Hinge ◽  
Leaf Spring ◽  
Element Analysis ◽  
Sizing Optimization ◽  
Flexure Hinges ◽  
Spring Type ◽  
Micro Motion ◽  
Motion Stage

Flexure hinge is widely used in the compliant mechanisms for precision engineering. Generally, compliant mechanisms with flexure hinges are designed using the analytical stiffness formulas, which increases the design complexity. As the development of finite element analysis (FEA) and optimization methods, it is likely to design the flexure hinges directly using the FEA based numerical optimization methods. This paper developed a leaf spring type flexure hinge based micro-motion stage with specific stiffness constraints. Both topology and sizing optimization methods are used in the design of motion stage. The proposed methods is apply to optimal design formed the leaf spring type flexure hinge for a micro motion stage which serves as a guidance mechanism. Further numerical result shows the good stiffness stability of the refined stage.

Design and Analysis of a Compact Piezo-actuated Microgripper with a Large Amplification Ratio

2021 ◽  
pp. 1-5
Author(s):  
Fangxin Chen ◽  
Qianjun Zhang ◽  
Yongzhuo Gao ◽  
Wei Dong
Keyword(s):  
Finite Element Analysis ◽  
Design Methodology ◽  
Compliant Mechanisms ◽  
Experimental Studies ◽  
Flexure Hinge ◽  
Element Analysis ◽  
Compact Structure ◽  
Amplification Ratio ◽  
Parasitic Motion ◽  
Structure Dimension

Abstract Abstract This paper presents a piezo-actuated microgripper characterized by large amplification ratio and compact structure size. The microgripper is actuated by a piezo-stack actuator that is integrated with a two-stage displacement amplifier to achieve large travel range. A new design methodology “flexure hinge individualized design” (FHID) was proposed to realize large amplification ratio. According to this methodology, each flexure hinge was designed personally based on force condition of the piviot to reconfigure the motion stiffness of the compliant microgripper so that the parasitic motion and displacement loss could be eliminated. Consequently, a 52-amplification-ratio amplifier was obtained. The developed microgripper was modeled via kinematics and Castigliano's displacement theorem, respectively. Finite element analysis and the experimental studies were conducted to evaluate the characteristics of the microgripper. The results show that the motion stroke of the gripper-tip is 917 μm, and the structure dimension is 62 mm × 42 mm ×12 mm. The design methodology FHID is generic and can be extended to other compliant mechanisms.

Optimization of Compliant Mechanisms by Use of Different Polynomial Flexure Hinge Contours

2019 ◽  
pp. 265-274 ◽  
Author(s):  
P. Gräser ◽  
S. Linß ◽  
L. Zentner ◽  
R. Theska
Keyword(s):  
Compliant Mechanisms ◽  
Flexure Hinge

Burgers viscoelastic model-based variable stiffness design of compliant clamping mechanism for leafy greens harvesting

2021 ◽  
Vol 208 ◽  
pp. 1-15
Author(s):  
Liangliang Zou ◽  
Jin Yuan ◽  
Xuemei Liu ◽  
Jinguang Li ◽  
Ping Zhang ◽  
...  
Keyword(s):  
Viscoelastic Model ◽  
Variable Stiffness ◽  
Leafy Greens ◽  
Model Based ◽  
Stiffness Design

Bistable Compliant Four-Bar Mechanisms With a Single Torsional Spring

2006 ◽  
Author(s):  
Adarsh Mavanthoor ◽  
Ashok Midha
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Mechanism Design ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Stored Energy ◽  
Element Analysis ◽  
Bistable Behavior ◽  
Torsional Spring ◽  
Bistable Mechanism

Significant reduction in cost and time of bistable mechanism design can be achieved by understanding their bistable behavior. This paper presents bistable compliant mechanisms whose pseudo-rigid-body models (PRBM) are four-bar mechanisms with a torsional spring. Stable and unstable equilibrium positions are calculated for such four-bar mechanisms, defining their bistable behavior for all possible permutations of torsional spring locations. Finite Element Analysis (FEA) and simulation is used to illustrate the bistable behavior of a compliant mechanism with a straight compliant member, using stored energy plots. These results, along with the four-bar and the compliant mechanism information, can then be used to design a bistable compliant mechanism to meet specified requirements.

A Geometric Parametric Analysis of a Magnetorheological Engine Mount

2010 ◽  
Author(s):  
Walter Anderson ◽  
Constantine Ciocanel ◽  
Mohammad Elahinia
Keyword(s):  
High Frequency ◽  
New Technology ◽  
Low Frequency ◽  
Variable Stiffness ◽  
Small Displacement ◽  
Element Analysis ◽  
Mr Fluid ◽  
Wide Range ◽  
Engine Mount ◽  
Vehicle Technology

Engine vibration has caused a great deal of research for isolation to be performed. Traditionally, isolation was achieved through the use of pure elastomeric (rubber) mounts. However, with advances in vehicle technology, these types of mounts have become inadequate. The inadequacy stems from the vibration profile associated with the engine, i.e. high displacement at low frequency and small displacement at high frequency. Ideal isolation would be achieved through a stiff mount for low frequency and a soft mount for high frequency. This is contradictory to the performance of the elastomeric mounts. Hydraulic mounts were then developed to address this problem. A hydraulic mount has variable stiffness and damping due to the use of a decoupler and an inertia track. However, further advances in vehicle technology have rendered these mounts inadequate as well. Examples of these advances are hybridization (electric and hydraulic) and cylinder on demand (VCM, MDS & ACC). With these technologies, the vibration excitation has a significantly different profile, occurs over a wide range of frequencies, and calls for a new technology that can address this need. Magnetorheological (MR) fluid is a smart material that is able to change viscosity in the presence of a magnetic field. With the use of MR fluid, variable damping and stiffness can be achieved. An MR mount has been developed and tested. The performance of the mount depends on the geometry of the rubber part as well as the behavior of the MR fluid. The rubber top of the mount is the topic of this study due to its major impact on the isolation characteristics of the MR mount. To develop a design methodology to address the isolation needs of different hybrid vehicles, a geometric parametric finite element analysis has been completed and presented in this paper.

Sign in / Sign up

Export Citation Format

Share Document