scholarly journals Generalized model for conic-V-shaped flexure hinges

2020 ◽  
Vol 103 (4) ◽  
pp. 003685042098121
Author(s):  
Jianyi Kong ◽  
Zhao Huang ◽  
Xiaodong Xian ◽  
Yingrui Wang ◽  
Puliang Yu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Nonlinear Equations ◽  
Polar Coordinates ◽  
Generalized Equations ◽  
Element Analysis ◽  
Generalized Model ◽  
New Class ◽  
Flexure Hinges ◽  
Dimensional Parameters

This paper presents a new class of flexure hinges, namely, conic-V-shaped flexure hinges (CFHs), which can be used as a generalized model for flexure hinges with profiles such as parabolic-V-shape, elliptical-V-shape, and hyperbolic-V-shape. Compliance and precision equations for the CFHs were derived as a set of nonlinear equations using Castigliano’s second theorem. The parameters of the nonlinear equations inputted to the compliance and precision matrices were based on the generalized equations used for conic curves in polar coordinates. Furthermore, the compliance equations were verified by means of finite element analysis and experiments. The errors in the finite element and experimental results were within 10% and 8% compared to the analytical results, respectively. Finally, the effects of dimensional parameters on the analytical model could be effectively analyzed by numerical simulations and comparisons.

scholarly journals Analysis of Bridge-type Distributed-compliance Mechanism

2018 ◽  
Vol 213 ◽  
pp. 01005
Author(s):  
Lei-Jie Lai ◽  
Xiao-Qia Yin
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Analytical Model ◽  
Element Analysis ◽  
Amplification Ratio ◽  
Flexure Hinges ◽  
The Finite Element Analysis ◽  
Practical Design ◽  
Bridge Type ◽  
Compliance Mechanism

This paper analyses a class of bridge-type distributed-compliance mechanism, which has better performances than traditional bridge-type mechanisms using notch flexure hinges. An analytical model for the displacement amplification ratio and input stiffness calculations of the bridge-type mechanism is established based on the stiffness matrix method. The finite element analysis results are then given to validate the correctness of the analytical model. The differences of the analytical results with respect to the finite element analysis results are less than 8%, which demonstrate the high accuracy of the analytical model. The influences of the geometric parameters on the amplification ratio and input stiffness of the mechanism are also investigated using the analytical model to provide theoretical guidelines for the practical design.

scholarly journals Analytical Compliance Equations of Generalized Elliptical-Arc-Beam Spherical Flexure Hinges for 3D Elliptical Vibration-Assisted Cutting Mechanisms

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 5928
Author(s):  
Han Wang ◽  
Shilei Wu ◽  
Zhongxi Shao
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Flexure Hinge ◽  
Matrix Formulation ◽  
Element Analysis ◽  
Compliance Matrix ◽  
Flexure Hinges ◽  
Elliptical Vibration ◽  
Relative Standard ◽  
Cutting Mechanisms

Elliptical vibration-assisted cutting technology has been widely applied in complicated functional micro-structured surface texturing. Elliptical-arc-beam spherical flexure hinges have promising applications in the design of 3D elliptical vibration-assisted cutting mechanisms due to their high motion accuracy and large motion ranges. Analytical compliance matrix formulation of flexure hinges is the basis for achieving high-precision positioning performance of these mechanisms, but few studies focus on this topic. In this paper, analytical compliance equations of spatial elliptic-arc-beam spherical flexure hinges are derived, offering a convenient tool for analysis at early stages of mechanism design. The mechanical model of a generalized flexure hinge is firstly established based on Castigliano's Second Theorem. By introducing the eccentric angle as the integral variable, the compliance matrix of the elliptical-arc-beam spherical flexure hinge is formulated. Finite element analysis is carried out to verify the accuracy of the derived analytical compliance matrix. The compliance factors calculated by the analytical equations agree well with those solved in the finite element analysis for the maximum error; average relative error and relative standard deviation are 8.25%, 1.83% and 1.78%, respectively. This work lays the foundations for the design and modeling of 3D elliptical vibration-assisted cutting mechanisms based on elliptical-arc-beam spherical flexure hinges.

Parametric Study of Nozzle Connections in Ellipsoidal Head Pressure Vessel

2013 ◽  
Vol 393 ◽  
pp. 360-365
Author(s):  
Haszeme Abu Kasim ◽  
Wahyu Kuntjoro
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Parametric Study ◽  
Geometrical Parameters ◽  
Load Case ◽  
Element Analysis ◽  
Dimensional Parameters ◽  
Head Pressure ◽  
Radial Nozzle

This paper presents 3-D solid structural modeling and stress analysis of radial nozzle connections in ellipsoidal heads vessel subjected to internal pressure and various external loadings. Finite Element Analysis (FEA) method was utilized to determine the stress distribution at the intersection of a radial nozzle attached to the ellipsoidal head. In order to get better understanding of the structure behavior, a parametric study was carried out to determine influences of the geometrical parameters. All the results analysis was presented as graphs of non-dimensional parameters against stress concentration factor (SCF) for each load case applied.

scholarly journals New empirical stiffness equations for corner-filleted flexure hinges

2013 ◽  
Vol 4 (2) ◽  
pp. 345-356 ◽  
Author(s):  
Q. Meng ◽  
Y. Li ◽  
J. Xu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Large Deformation ◽  
Flexure Hinge ◽  
Minimum Thickness ◽  
Element Analysis ◽  
Flexure Hinges ◽  
Fillet Radius

Abstract. This paper investigates the existing stiffness equations for corner-filleted flexure hinges. Three empirical stiffness equations for corner-filleted flexure hinges (each fillet radius, r, equals to 0.1 l; l, the length of a corner-filleted flexure hinge) are formulated based on finite element analysis results for the purpose of overcoming these investigated limitations. Three comparisons made with the existing compliance/stiffness equations and finite element analysis (FEA) results indicate that the proposed empirical stiffness equations enlarge the range of rate of thickness (t, the minimum thickness of a corner-filleted flexure hinge) to length (l), t/l (0.02 ≤ t/l ≤ 1) and ensure the accuracy for each empirical stiffness equation under large deformation. The errors are within 6% when compared to FEA results.

Design and Optimization of a New Hollow Circular Flexure Hinge for Precision Mechanisms

2019 ◽  
Vol 889 ◽  
pp. 337-345 ◽  
Author(s):  
Van Khien Nguyen ◽  
Duy Luong Tuong ◽  
Huy Tuan Pham ◽  
Huy Hoang Pham
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Optimization Procedure ◽  
Longitudinal Axis ◽  
Maximum Load ◽  
Flexure Hinge ◽  
Element Analysis ◽  
Design And Optimization ◽  
Parasitic Motion ◽  
Flexure Hinges

Flexure hinges have been used in many precision mechanisms where repeatable, friction free motion and high precision are required. Many kinds of flexure profiles have been proposed during the past decade. This paper presents a new type of flexure hinge which combines circular longitudinal axis beams to form hollow joint. This novel design will help to improve the range of motion, reduce stress level and increase the maximum load before yielding. Due to its special design, the cavity inside the hinge can also be filled with an elastomeric filler material to provide vibration damping. In order to synthesis this hinge, shape optimization integrating genetic algorithm and response surface methodology is used. The optimization procedure is programmed in MATLAB whereas finite element analysis in ANSYS is also embedded into the codes to enhance the calculation process. The new flexure hollow hinge is compared to the conventional straight-axis solid hinges (circular, elliptical and corner-filleted flexure hinges) in terms of stiffness, rotational precision and stress levels. It is also supposed that this new design would increase the precision of the mechanism due to reducing the parasitic motion. Finite element analysis in ANSYS is used to verify for the viability of the design before it can be fabricated and tested.

Nonlinear static modeling of a tip-tilt-piston micropositioning stage comprising leaf-spring flexure hinges

2020 ◽  
Vol 234 (10) ◽  
pp. 1969-1978
Author(s):  
Guozhen Chen ◽  
Pinkuan Liu ◽  
Han Ding
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Leaf Spring ◽  
Element Analysis ◽  
Flexure Hinges ◽  
The Finite Element Analysis ◽  
Static Modeling ◽  
Nonlinear Static ◽  
Force Displacement ◽  
Theoretical Results

Nonlinear static modeling is crucial for the design of stages with large travel ranges. However, few studies have investigated complex spatial compliant mechanisms. The present study proposes an optimization algorithm based on substructure constraint conditions to formulate the nonlinearity of the force–displacement characteristic of a tip-tilt-piston stage comprising leaf-spring flexure hinges. First, the nonlinear force–displacement characteristics of the compound basic parallelogram mechanism are derived using an optimization algorithm based on two constraint conditions (I and II). Second, the nonlinear static modeling of the tip-tilt-piston stage is conducted based on the modeling results of the compound basic parallelogram mechanism. The stage is divided into three parts, and force analyses are conducted for all three parts. The vertical displacement of the compound basic parallelogram mechanism in part 1 and the rotational angle of the rotational plate in part 2 are calculated. Subsequently, the force–displacement characteristics of the tip-tilt-piston stage are obtained based on a third constraint condition (III). A comparison of the finite element analysis results and the theoretical calculation indicates less than 4% errors. In the experimental tests conducted on the proposed stage and four compound basic parallelogram mechanisms, the displacements were evidently larger than those calculated using the finite element analysis. Therefore, a weight coefficient of the axial force w is introduced in the theoretical calculation to solve the problem of the large deviations between the experimental results and the finite element analysis results. When w is set to 1, the theoretical results are in good agreement with the finite element analysis results; when w is set to 0.05 for the tip-tilt-piston stage and 0.15 for compound basic parallelogram mechanisms, the theoretical results are consistent with the experimental results (less than 8.5% errors).

Extended Formability Limits for Tubular Components Through Combined Injection Forming/Upsetting—A Finite Element Analysis

1995 ◽  
Vol 209 (2) ◽  
pp. 107-114 ◽  
Author(s):  
S B Petersen ◽  
J M C Rodrigues ◽  
P A F Martins
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Numerical Simulations ◽  
Wall Thickness ◽  
Experimental Work ◽  
Element Analysis ◽  
Dimensional Parameters ◽  
Process Mechanics ◽  
Gap Height ◽  
Tubular Components

In the injection forming/upsetting of tabular parts the ratio between inner and outer diameters of the tube, the ratio between wall thickness and gap height, together with the design of the die chamber are important dimensional parameters that determine the final geometry of a component. Recent published work in this field opened a breakthrough in the understanding of the limits for obtaining sound components without folds. However, some difficulties were still encountered, namely in what concerns avoiding the presence of undesirable models of deformation. The paper presents comprehensive modelling of previous experimental work in this field, which leads to a re-examination of the process mechanics. This effort resulted in the development of a combined injection forming/upsetting technique. Numerical simulations performed using this technique indicate that a large extension of the formability limit for tubular components is possible.

Micropositioning System with Flexure Hinges for Microfactories

2013 ◽  
Vol 581 ◽  
pp. 485-490 ◽  
Author(s):  
Daniel Lates ◽  
Simona Noveanu ◽  
Vencel Iosif Csibi
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Coordinate System ◽  
Experimental Work ◽  
Two Dimensional ◽  
Element Analysis ◽  
Flexure Hinges ◽  
Micropositioning System

In this paper it is presented a ductile system for micropositioning in a two-dimensional coordinate system. Accuracy positioning results from usage of asymmetric flexure hinges. It also it is presented the modeling of the asymmetric flexure hinges, finite element analysis, and experimental work. For the micropositioning system are determined both theoretical and experimental displacements and stress. The system consists of three actuators which are individually controlled.

scholarly journals Optimal Design for Compliant Mechanism Flexure Hinges: Bridge-Type

Micromachines ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1304
Author(s):  
Chia-Nan Wang ◽  
Fu-Chiang Yang ◽  
Van Thanh Tien Nguyen ◽  
Quoc Manh Nguyen ◽  
Ngoc Thai Huynh ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Taguchi Method ◽  
Compliant Mechanism ◽  
Element Analysis ◽  
Flexure Hinges ◽  
Bridge Type ◽  
Optimal Values ◽  
Grey Relational ◽  
Good Agreement

Compliant mechanisms’ design aims to create a larger workspace and simple structural shapes because these mechanical systems usually have small dimensions, reduced friction, and less bending. From that request, we designed optimal bridge-type compliant mechanism flexure hinges with a high magnification ratio, low stress by using a flexure joint, and especially no friction and no bending. This joint was designed with optimal dimensions for the studied mechanism by using the method of grey relational analysis (GRA), which is based on the Taguchi method (TM), and finite element analysis (FEA). Grey relational grade (GRG) has been estimated by an artificial neural network (ANN). The optimal values were in good agreement with the predicted value of the Taguchi method and regression analysis. The finite element analysis, signal-to-noise analysis, surface plot, and analysis of variance demonstrated that the design dimensions significantly affected the equivalent stress and displacement. The optimal values of displacement were also verified by the experiment. The outcomes were in good agreement with a deviation lower than 6%. Specifically, the displacement amplification ratio was obtained as 65.36 times compared with initial design.

Elliptical-Arc-Fillet Flexure Hinges: Toward a Generalized Model for Commonly Used Flexure Hinges

2011 ◽  
Vol 133 (8) ◽  
Author(s):  
Guimin Chen ◽  
Xiaoyuan Liu ◽  
Yunlei Du
Keyword(s):  
Finite Element ◽  
Strain Energy ◽  
Single Type ◽  
Flexure Hinge ◽  
Circular Arc ◽  
Generalized Model ◽  
Percent Error ◽  
New Class ◽  
Flexure Hinges ◽  
Hinge Model

Flexure hinges have been used to produce frictionless and backlashless transmissions in a variety of precision mechanisms. Although there are many types of flexure hinges available, designers often chose a single type of flexure hinge (e.g., circular flexure hinges) without considering others in the design of flexure-based mechanisms. This is because the analytical equations are unique to each kind of flexure hinge. This work offers a solution to this problem in the form of a generalized flexure hinge model. We propose a new class of flexure hinges, namely, elliptical-arc-fillet flexure hinges, which brings elliptical arc, circular-arc-fillet, elliptical-fillet, elliptical, circular, circular-fillet, and right-circular flexure hinges together under one set of equations. The closed-form equations for all the elements in the compliance and precision matrices of elliptical-arc-fillet flexure hinges have been derived. The analytical results are within 10 percent error compared to the finite element results and within 8 percent error compared to the experimental results. The equations for evaluating the strain energy and stress level for elliptical-arc-fillet flexure hinges are also provided. This model can be used as a complementary model for the generalized model for conic flexure hinges.

Sign in / Sign up

Export Citation Format

Share Document