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 ◽  
...  

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.

2018 ◽  
Vol 213 ◽  
pp. 01005
Author(s):  
Lei-Jie Lai ◽  
Xiao-Qia Yin

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.


Author(s):  
Giovanni Berselli ◽  
Rocco Vertechy ◽  
Gabriele Vassura ◽  
Vincenzo Parenti Castelli

The interest in actuators based on dielectric elastomer films as a promising technology in robotic and mechatronic applications is increasing. The overall actuator performances are influenced by the design of both the active film and the film supporting frame. This paper presents a single-acting actuator which is capable of supplying a constant force over a given range of motion. The actuator is obtained by coupling a rectangular film of silicone dielectric elastomer with a monolithic frame designed to suitably modify the force generated by the dielectric elastomer film. The frame is a fully compliant mechanism whose main structural parameters are calculated using a pseudo-rigid-body model and then verified by finite element analysis. Simulations show promising performance of the proposed actuator.


Author(s):  
Adarsh Mavanthoor ◽  
Ashok Midha

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.


2009 ◽  
Vol 131 (4) ◽  
Author(s):  
H. F. Wang ◽  
Z. F. Sang ◽  
L. P. Xue ◽  
G. E. O. Widera

The burst pressure of cylinders with hillside nozzle is determined using both experimental and finite element analysis (FEA) approaches. Three full-scale test models with different angles of the hillside nozzle were designed and fabricated specifically for a hydrostatic test in which the cylinders were pressurized with water. 3D static nonlinear finite element simulations of the experimental models were performed to obtain the burst pressures. The burst pressure is defined as the internal pressure for which the structure approaches dimensional instability, i.e., unbounded strain for a small increment in pressure. Good agreement between the predicted and measured burst pressures shows that elastic-plastic finite element analysis is a viable option to estimate the burst pressure of the cylinders with hillside nozzles. The preliminary results also suggest that the failure location is near the longitudinal plane of the cylinder-nozzle intersection and that the burst pressure increases slightly with an increment in the angle of the hillside nozzle.


2019 ◽  
Vol 894 ◽  
pp. 60-71
Author(s):  
Minh Phung Dang ◽  
Thanh Phong Dao ◽  
Hieu Giang Le ◽  
Ngoc Thoai Tran

A Compliant XY micropositioning stage is purported for situating a material sample in nanoindentation tester process. This paper aims to develop, analyze and optimize a XY compliant micropositioning stage. The working stroke of proposed XY stage is amplified by combining the four-lever and a bridge amplification mechanism. To enhance the performances of the stage, the main geometric parameters are optimized by an integration method of Taguchi method, response surface method (RSM) and genetic algorithm (GA). Firstly, static analysis and dynamic analysis are conducted by the finite element analysis in order to predict initial performances of the XY stage. Secondly, the number of experiments and the data are retrieved by combination of the finite element analysis-integrated Taguchi method. Thirdly, the effects of main design variables on the output response sensitivity are considered. Later on, mathematical model for the amplification ratio was established by the RSM. Finally, based on the mathematical equation, the GA is adopted to define the optimal design variables. The results of numerical validations are in a good agreement with the predicted results. The results depicted that the proposed hybrid approach ensures a high reliability for engineering optimization problems.


2013 ◽  
Vol 37 (3) ◽  
pp. 313-323 ◽  
Author(s):  
Kingsun Lee ◽  
Jui-Chang Lin

The unibody of LED (light-emitting diodes) lampshades is fabricated by injection mold; the forming technique is complicated, especially for multi-cavity molds. This study applies a finite element analysis to explore the influences of the shrinkage of LED lampshades. The effect of selected injection parameters and their levels on shrinkage size, and the subsequent design of experiments were accomplished using the Taguchi method. The results were confirmed by experiments, which indicated that the selected injection parameters effectively reduce the shrinkage. The error between optimal estimated value and verified value is within 3.82%.


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