Optimization of Translational Flexure Joints Using Corrugated Units Under Stress Constraints

2021 ◽  
pp. 1-12
Author(s):  
Canran Li ◽  
Nianfeng Wang ◽  
Fan Yue ◽  
Xianmin Zhang
Keyword(s):  
Natural Frequency ◽  
Stiffness Matrix ◽  
Maximum Stress ◽  
Stress Constraints ◽  
Axial Stiffness ◽  
Stiffness Ratio ◽  
Maximum Displacement ◽  
Element Analysis ◽  
Different Types ◽  
Flexure Joints

Abstract When optimizing 2-DOF corrugated flexure stages, most approaches for calculating the maximum stress on the corrugated flexure (CF) beam depend on finite element analysis (FEA). The current paper introduces the design optimization for stages using CF units under stress constraints. The stress state is solved; then, based on that, the maximum displacement under stress constraints is deduced. The natural frequency formula of the micropositioning stage is further derived from the results of the stiffness matrix. The stage configurations corresponding to the maximum displacement are optimized by restricting the off-axis/axial stiffness ratio and natural frequency of the stage. The optimal results of different types are validated by FEA and experiments.

Optimization of a 2DOF Positioning Stage Using Corrugated Flexure Units Under Stress Constraints

2019 ◽  
Author(s):  
Nianfeng Wang ◽  
Fan Yue ◽  
Canran Li ◽  
Xianmin Zhang
Keyword(s):  
Stress State ◽  
Design Optimization ◽  
Natural Frequency ◽  
Stiffness Matrix ◽  
Stress Constraints ◽  
Axial Stiffness ◽  
Stiffness Ratio ◽  
Maximum Displacement ◽  
Positioning Stage

Abstract The paper introduces the design optimization for micro-positioning stage using corrugated flexure (CF) units under stress constraints. The stress state is solved and the maximum displacement under stress constraints is deduced. The natural frequency formula of the micro-positioning stage is further derived from the results of the stiffness matrix. Finally, the stage configurations corresponding to the maximum displacement are optimized by restricting the off-axis/axial stiffness ratio and natural frequency of the stage.

Design of a Micro-Positioning Stage Using Corrugated Flexure Beam With Cubic Bézier Curve Segments

2018 ◽  
Author(s):  
Nianfeng Wang ◽  
Zhiyuan Zhang ◽  
Xianmin Zhang
Keyword(s):  
Stiffness Matrix ◽  
Matrix Method ◽  
Bézier Curve ◽  
Bezier Curve ◽  
Axial Stiffness ◽  
Control Points ◽  
Stiffness Ratio ◽  
Element Analysis ◽  
Positioning Stage ◽  
Cubic Bezier Curve

The paper introduces an analytical stiffness matrix method to model a new type of corrugated flexure (CF) beam with cubic Bézier curve segments. In order to satisfy particular design specifications, shape variation for limited geometric envelopes are often employed to alter the elastic properties of flexure hinges. In this paper, cubic Bézier curves are introduced to replace the axis of CF unit to rebuild the CF beam and the micro-positioning stage. Mohr’s integral method is applied to derive the stiffness matrix of the cubic Bézier curve segment. Modeling of the CF unit and the CF beam with cubic Bézier curve segments are further carried out through stiffness matrix method, which are confirmed by finite element analysis (FEA). Discussions about the two control points of the cubic Bézier curve segments are then conducted through search optimization, which highlights the off-axis/axial stiffness ratio and the axial compliance on the position of the two control points, to enable the micro-positioning stage both achieving high off-axis/axial stiffness ratio and large axial compliance. The derived analytical model provides a new option for the design of the CF beam.

scholarly journals An Investigation into a Gear-Based Knee Joint Designed for Lower Limb Prosthesis

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
M. S. H. Bhuiyan ◽  
I. A. Choudhury ◽  
M. Dahari ◽  
Y. Nukman ◽  
S. Z. Dawal
Keyword(s):  
Knee Joint ◽  
Motion Analysis ◽  
Maximum Stress ◽  
Real Data ◽  
Fe Analysis ◽  
Knee Prostheses ◽  
Maximum Displacement ◽  
Element Analysis ◽  
Lower Limb Prosthesis ◽  
Limb Prosthesis

A gear-based knee joint is designed to improve the performance of mechanical-type above-knee prostheses. The gear set with the help of some bracing, and bracket arrangement, is used to enable the prosthesis to follow the residual limb movement. The motion analysis and finite-element analysis (FEA) of knee joint components are carried out to assess the feasibility of the design. The maximum stress of 29.74 MPa and maximum strain of 2.393e−004 are obtained in the gear, whereas the maximum displacement of 7.975 mm occurred in the stopper of the knee arrangement. The factor of safety of 3.5 obtained from the FE analysis indicated no possibility of design failure. The results obtained from the FE analysis are then compared with the real data obtained from the literature for a similar subject. The pattern of motion analysis results has shown a great resemblance with the gait cycle of a healthy biological limb.

scholarly journals Nonlinear Finite Element Analysis of the Fluted Corrugated Sheet in the Corrugated Cardboard

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Zhiguo Zhang ◽  
Tao Qiu ◽  
Riheng Song ◽  
Yaoyu Sun
Keyword(s):  
Finite Element Analysis ◽  
Maximum Stress ◽  
Static Pressure ◽  
Nonlinear Finite Element ◽  
Drop Test ◽  
Maximum Displacement ◽  
Element Analysis ◽  
Corrugated Board ◽  
Pressure Test ◽  
Corrugated Cardboard

The choice of corrugated medium, flute size, combining adhesive, and linerboards can be varied to design a corrugated board with specific properties. In this paper, the nonlinear finite element analysis of the fluted corrugated sheet in the corrugated cardboard based on software SolidWorks2008 was investigated. The model of corrugated board with three or more flutes is reliable for stress and displacement measurement to eliminate the influence of the number of flutes in models. According to the static pressure test, with the increase of flute heightHor arc radius of flute, the maximum stress in the models decreased and the maximum displacement increased. However the maximum stress and maximum displacement in the models increase nonlinearly in the static pressure test with the increase of the flute angleθ. According to the drop test, with the increase of flute heightH, the maximum stress of goods on the upper board in the drop test decreased. The maximum stress of the model in the drop test decreases firstly and then increases with the increase of flute angle, and the optimal flute angleθcould be 60° for corrugated board. All the conclusions are consistent with experimental data or product standards.

scholarly journals An Approach of Vibration Control Based on the Design of Three DOFs Active Vibration Damping Platform

2019 ◽  
Vol 224 ◽  
pp. 05010
Author(s):  
Yi Ye ◽  
Miaoxian Guo
Keyword(s):  
Numerical Simulations ◽  
Vibration Control ◽  
Natural Frequency ◽  
Maximum Stress ◽  
Active Vibration Control ◽  
Vibration Damping ◽  
Yield Limit ◽  
Maximum Displacement ◽  
Active Vibration Damping ◽  
Active Vibration

In this paper, an active vibration control platform is developed for milling processes. In this system, the workpiece is driven by a specially designed active platform to control the relative vibration between the tool and workpiece during milling processes. Numerical simulations are carried out to validate the effectiveness of the control platform. Results indicate that maximum stress of the hinge mechanism of the platform is far less than the yield limit of the material, and the designed platform can meet the use requirements in terms of the maximum displacement and natural frequency.

Seismic analysis of the rail-counterweight system in elevators considering the stiffness of rail brackets

2020 ◽  
pp. 136943322097477
Author(s):  
Xiaoyan Wang ◽  
Selim Günay ◽  
Wensheng Lu
Keyword(s):  
Maximum Stress ◽  
Seismic Analysis ◽  
Stiffness Ratio ◽  
Continuous Beam ◽  
Seismic Responses ◽  
Maximum Displacement ◽  
Maximum Deformation ◽  
Simply Supported ◽  
System A ◽  
Earthquake Characteristics

The rail in the rail-counterweight system in elevators is vertically supported along the building height by the rail brackets. In the numerical model of the rail-counterweight system, the rail-bracket assembly is modelled as a continuous beam supported by linear springs representing the rail brackets and the stiffness of the bracket is contributed to the overall stiffness of the rail-bracket assembly. To investigate the effect of the rail brackets on the seismic responses of the rail-counterweight system, a parameter named “stiffness ratio” is proposed in a rail-bracket assembly, defined as the ratio of the stiffness of the bracket to that of the simply supported continuous beam representing the rail at mid-span of an intermediate span. The stiffness of the brackets is varied by changing the stiffness ratio of the rail-bracket assembly, and the corresponding seismic responses of the rail-counterweight system are analyzed, including the maximum stress in the rail, the maximum deformation of the brackets, and the maximum displacement of the roller guide off the rail. A comprehensive analysis is conducted by considering four rail spans and three earthquake motions. The variations of the responses with the increasing stiffness ratio are dependent on the earthquake characteristics and the rail spans. The less the rail span is, the less important the effects of the stiffness ratio are. Nevertheless, the seismic responses of the rail-counterweight system generally have little change when the stiffness ratio is up to 4 and more. It is indicated that increasing of the stiffness ratio are not necessarily capable of improving the seismic performance of the counterweight system, especially when the stiffness ratio or the stiffness coefficient of the brackets is large, varying the stiffness ratio is unhelpful to change the rail-counterweight responses.

A Patient-Specific Computer Tomography-Based Finite Element Methodology to Calculate the Six Dimensional Stiffness Matrix of Human Vertebral Bodies

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
Yan Chevalier ◽  
Philippe K. Zysset
Keyword(s):  
Finite Element ◽  
Structural Properties ◽  
Vertebral Body ◽  
Computer Tomography ◽  
Stiffness Matrix ◽  
Anisotropic Elasticity ◽  
Patient Specific ◽  
Axial Stiffness ◽  
Element Analysis ◽  
Vertebral Bodies

In most finite element (FE) studies of vertebral bodies, axial compression is the loading mode of choice to investigate structural properties, but this might not adequately reflect the various loads to which the spine is subjected during daily activities or the increased fracture risk associated with shearing or bending loads. This work aims at proposing a patient-specific computer tomography (CT)-based methodology, using the currently most advanced, clinically applicable finite element approach to perform a structural investigation of the vertebral body by calculation of its full six dimensional (6D) stiffness matrix. FE models were created from voxel images after smoothing of the peripheral voxels and extrusion of a cortical shell, with material laws describing heterogeneous, anisotropic elasticity for trabecular bone, isotropic elasticity for the cortex based on experimental data. Validated against experimental axial stiffness, these models were loaded in the six canonical modes and their 6D stiffness matrix calculated. Results show that, on average, the major vertebral rigidities correlated well or excellently with the axial rigidity but that weaker correlations were observed for the minor coupling rigidities and for the image-based density measurements. This suggests that axial rigidity is representative of the overall stiffness of the vertebral body and that finite element analysis brings more insight in vertebral fragility than densitometric approaches. Finally, this extended patient-specific FE methodology provides a more complete quantification of structural properties for clinical studies at the spine.

scholarly journals Comparative Analysis of Stress and Deformation between One-Fenced and Three-Fenced Dental Implants Using Finite Element Analysis

2021 ◽  
Vol 10 (17) ◽  
pp. 3986
Author(s):  
Chia-Hsuan Lee ◽  
Arvind Mukundan ◽  
Szu-Chien Chang ◽  
Yin-Lai Wang ◽  
Shu-Hao Lu ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Comparative Analysis ◽  
Stress Distribution ◽  
Dental Implant ◽  
Maximum Stress ◽  
Vertical Force ◽  
Element Analysis ◽  
Different Types ◽  
Stress And Deformation

Finite element analysis (FEA) has always been an important tool in studying the influences of stress and deformation due to various loads on implants to the surrounding jaws. This study assessed the influence of two different types of dental implant model on stress dissipation in adjoining jaws and on the implant itself by utilizing FEA. This analysis aimed to examine the effects of increasing the number of fences along the implant and to compare the resulting stress distribution and deformation with surrounding bones. When a vertical force of 100 N was applied, the largest displacements found in the three-fenced and single-fenced models were 1.7469 and 2.5267, respectively, showing a drop of 30.8623%. The maximum stress found in the three-fenced and one-fenced models was 13.518 and 22.365 MPa, respectively, showing a drop of 39.557%. Moreover, when an oblique force at 35° was applied, a significant increase in deformation and stress was observed. However, the three-fenced model still had less stress and deformation compared with the single-fenced model. The FEA results suggested that as the number of fences increases, the stress dissipation increases, whereas deformation decreases considerably.

Finite Element Analysis and Optimal Design for Mold Shelf of Powder Molding Press

2010 ◽  
Vol 34-35 ◽  
pp. 1559-1562
Author(s):  
Jun Liu ◽  
Xiao Zhou ◽  
Gang Yi Zhou ◽  
Xin Long Dong
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Optimal Design ◽  
Load Distribution ◽  
Maximum Stress ◽  
Ansys Software ◽  
Maximum Displacement ◽  
Element Analysis ◽  
Load Component ◽  
Main Support

Mold shelf of powder molding press(PMP) is the main load component. Control the deformation of mold shelf is a key problem. In this paper, based on the basic theory of finite element analysis(FEA), the constraints and load conditions of main support parts of mold shelf were simulated and analyzed . ANSYS software optimized the structure of mold shelf. Top width of the stress part increased to 15mm, its height from 80mm down to 50mm. The results showed that the maximum displacement of mold shelf reduced to 0.4740mm, the maximum stress reduced 843.44MPa to 742.38MPa. Load distribution of the mold is more uniform, deformation and displacement also improved. It provides a new method and theoretical basis for optimal design of powder molding shelf.

Exploration of Translational Joint Design Using Corrugated Flexure Units With Bézier Curve Segments

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Nianfeng Wang ◽  
Zhiyuan Zhang ◽  
Fan Yue ◽  
Xianmin Zhang
Keyword(s):  
Stiffness Matrix ◽  
Matrix Method ◽  
Bézier Curve ◽  
Bezier Curve ◽  
Axial Stiffness ◽  
Shape Variation ◽  
Element Analysis ◽  
Joint Design ◽  
Translational Joint ◽  
Cubic Bezier Curve

In order to satisfy particular design specifications, shape variation for limited geometric envelopes is often employed to alter the elastic properties of flexure joints. This paper introduces an analytical stiffness matrix method to model a new type of corrugated flexure (CF) beam with cubic Bézier curve segments. The cubic Bézier curves are used to depict the segments combined to form CF beam and translational joint. Mohr's integral is applied to derive the local-frame compliance matrix of the cubic Bézier curve segment. The global-frame compliance matrices of the CF unit and the CF beam with cubic Bézier curve segments are further formed by stiffness matrix method, which are confirmed by finite element analysis (FEA). The control points of Bézier curve are chosen as optimization parameters to identify the optimal segment shape, which maximizes both high off-axis/axial stiffness ratio and large axial displacements of translational joint. The results of experimental study on the optimum translational joint design validate the proposed modeling and optimization method.

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