scholarly journals Load–Displacement Characterization in Three Degrees-of-Freedom for General Lamina Emergent Torsion Arrays

2020 ◽  
Vol 142 (9) ◽  
Author(s):  
Nathan A. Pehrson ◽  
Pietro Bilancia ◽  
Spencer Magleby ◽  
Larry Howell
Keyword(s):  
Degrees Of Freedom ◽  
Design Space ◽  
Element Analysis ◽  
Array Design ◽  
Elastic Load ◽  
In Series ◽  
Load Displacement ◽  
Stiffness Characteristics ◽  
Tunable Stiffness ◽  
Three Degrees Of Freedom

Abstract Lamina emergent torsion (LET) joints for use in origami-based applications enables folding of panels. Placing LET joints in series and parallel (formulating LET arrays) opens the design space to provide for tunable stiffness characteristics in other directions while maintaining the ability to fold. Analytical equations characterizing the elastic load–displacement for general serial–parallel formulations of LET arrays for three degrees-of-freedom are presented: rotation about the desired axis, in-plane rotation, and extension/compression. These equations enable the design of LET arrays for a variety of applications, including origami-based mechanisms. These general equations are verified using finite element analysis, and to show variability of the LET array design space, several verification plots over a range of parameters are provided.

Finite Element Analysis of 2-D Structures by New Strain Based Triangular Element

2018 ◽  
Vol 35 (3) ◽  
pp. 305-313 ◽  
Author(s):  
C. Rebiai
Keyword(s):  
Dynamic Analysis ◽  
Degrees Of Freedom ◽  
Numerical Solutions ◽  
Time Integration ◽  
Triangular Element ◽  
Membrane Element ◽  
Lumped Mass ◽  
Element Analysis ◽  
Benchmark Tests ◽  
Three Degrees Of Freedom

ABSTRACTIn this investigation, a new simple triangular strain based membrane element with drilling rotation for 2-D structures analysis is proposed. This new numerical model can be used for linear and dynamic analysis. The triangular element is named SBTE and it has three nodes with three degrees of freedom at each node. The displacements field of this element is based on the assumed functions for the various strains satisfying the compatibility equations. This developed element passed both patch and benchmark tests in the case of bending and shear problems. For the dynamic analysis, lumped mass with implicit/explicit time integration are employed. The obtained numerical results using the developed element converge toward the analytical and numerical solutions in both analyses.

FEM Based Numerical Simulation of Delta Parallel Mechanism

2013 ◽  
Vol 690-693 ◽  
pp. 2978-2981 ◽  
Author(s):  
Jian Zhong Zhang ◽  
Xin Peng Xie ◽  
Chuan Jin Li ◽  
Ying Ying Xin ◽  
Zhao Ming He
Keyword(s):  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Inverse Dynamics ◽  
Theoretical Foundation ◽  
Future Research ◽  
Element Analysis ◽  
Pick And Place ◽  
Integral Structure ◽  
Inverse Dynamics Analysis ◽  
Three Degrees Of Freedom

This paper describes a parallel three degrees of freedom delta mechanism used for pick-and-place. It has the advantages of simple integral structure, strong bearing capacityhigh precisionkinematics and dynamics performance. According to this mechanism wide development prospect, the company study on the inverse kinematics inverse dynamics analysis and the static analysis by using ANSYS finite element analysis Software of Delta. These analyses have laid a good theoretical foundation for future research. These researches provide possible for widely used in foodpackingautomated assembly line occasions of small and medium-sized enterprises.

Optimal Design of a 3-DOF Parallel Micromanipulator

2009 ◽  
Author(s):  
Dan Zhang ◽  
Zhen Gao ◽  
Beizhi Li
Keyword(s):  
Fiber Optics ◽  
Biomedical Engineering ◽  
Degrees Of Freedom ◽  
Radial Basis Function Networks ◽  
Element Analysis ◽  
Optics Industry ◽  
And Performance ◽  
And Behavior ◽  
Resultant Stress ◽  
Three Degrees Of Freedom

A new compliant parallel micromanipulator is proposed in this paper. The manipulator has three degrees of freedom (DOF) and can generate motions in a microscopic scale. It can be used for biomedical engineering and fiber optics industry. In the paper, the detailed design of the structure is first introduced, followed by the kinematic analysis and performance evaluation. Second, a finite-element analysis of resultant stress, strain, and deformations is evaluated based upon different inputs of the three piezoelectric actuators. Finally, the genetic algorithms and radial basis function networks are implemented to search for the optimal architecture and behavior parameters in terms of global stiffness, dexterity and manipulability.

scholarly journals Study of Double-Deck Vibrating Flip-Flow Screen Based on Dynamic Stiffness Characteristics of Shear Springs

Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 928
Author(s):  
Guofeng Zhao ◽  
Xinwen Wang ◽  
Dongdong Lin ◽  
Ningning Xu ◽  
Chi Yu ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Dynamic Stiffness ◽  
Frequency Characteristics ◽  
Spring Stiffness ◽  
Lower Shear ◽  
Screening Performance ◽  
Screening Efficiency ◽  
Stiffness Characteristics ◽  
Shear Spring ◽  
Three Degrees Of Freedom

Double-deck vibrating flip-flow screens have been widely used for the repurposing of decoration waste; however, the influence of shear spring stiffness on the screen’s vibration characteristics is under-researched. The shear spring stiffness affects the amplitude–frequency characteristics, phase–frequency characteristics, screening performance and processing capacity of the screen. In this paper, a mathematical model of the double-deck vibrating flip-flow screen is proposed based on a vibrating system with three degrees of freedom. Based on the experiments of the industrial screen, the amplitude–frequency and phase–frequency characteristics of the double-deck vibrating flip-flow screen were studied. Within the range of 25 to 75 rad/s, the amplitude of the main screen frame decreased gradually, the floating screen frames decreased at first and then increased and the amplitudes of the main and floating screen frames were dependent on the stiffness of the isolation springs and shear springs. When the frequency was 75 rad/s, the stiffness of the upper and lower shear springs was 11,440 kN/m, respectively, and the screening efficiency reached 97.09%.

scholarly journals An Investigation on a Novel 3-RCU Flexible Micromanipulator

Micromachines ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 423 ◽  
Author(s):  
Junnan Qian ◽  
Yangmin Li ◽  
Lukai Zhuge
Keyword(s):  
Carrying Capacity ◽  
Degrees Of Freedom ◽  
Transmission Efficiency ◽  
Element Analysis ◽  
Margin Of Error ◽  
Simulation Results ◽  
Amplification Mechanism ◽  
Working Performance ◽  
Three Degrees Of Freedom ◽  
Ansys Workbench

A novel type of spatial three revolute-cylindrical-universal (3-RCU) flexible micro manipulator is designed based on flexible hinges, and analyzed by finite element analysis (FEA). The piezoelectric actuators are adopted as driving devices in this platform, a new lever amplification mechanism is designed as its micro-displacement amplification mechanism, the workspace of the platform is enlarged, and the theoretical and simulation amplification ratios of the amplification mechanism are 3.056 and 2.985, respectively. The margin of error is just 2.3%. In space, the 3-RCU platform can realize the micro movement of three degrees of freedom. Also, the platform has a high carrying capacity, less motion loss, and the transmission efficiency is higher when the platform works. The decoupling performance, stress under extreme conditions and natural frequency of the platform are simulated by ANSYS Workbench software. A series of simulation analyses show the feasibility and security of the platform. The platform has good decoupling and working performance. The simulation results show that the platform has high simulation stiffness and high positioning accuracy.

Kinematic Analysis and Design of a Novel Shoulder Exoskeleton Using a Double Parallelogram Linkage

2018 ◽  
Vol 10 (4) ◽  
Author(s):  
Simon Christensen ◽  
Shaoping Bai
Keyword(s):  
Shoulder Joint ◽  
Degrees Of Freedom ◽  
Large Range ◽  
Upper Body ◽  
Element Analysis ◽  
Analysis And Design ◽  
Revolute Joints ◽  
Current State ◽  
Spherical Mechanism ◽  
Three Degrees Of Freedom

The design of an innovative spherical mechanism with three degrees-of-freedom (DOFs) for a shoulder joint exoskeleton is presented in this paper. The spherical mechanism is designed with a double parallelogram linkage (DPL), which connects two revolute joints to implement the motion as a spherical joint, while maintaining the remote center (RC) of rotation. The design has several new features compared to the current state-of-the-art: (1) a relative large range of motion (RoM) free of singularity, (2) high overall stiffness, (3) lightweight, and (4) compact, which make it suitable for assistive exoskeletons. In this paper, the kinematics and singularities are analyzed for the spherical mechanism and DPL. Dimensional analysis is carried out to find the design with maximum RoM. The new shoulder joint is finally designed, constructed, and integrated in a four degree-of-freedom wearable upper-body exoskeleton. A finite element analysis (FEA) study is used to assess the structural stiffness of the proposed design in comparison to the conventional 3R mechanism.

A two degrees of freedom comb capacitive-type accelerometer with low cross-axis sensitivity

2019 ◽  
Vol 13 (3) ◽  
pp. 5334-5346
Author(s):  
M. N. Nguyen ◽  
L. Q. Nguyen ◽  
H. M. Chu ◽  
H. N. Vu
Keyword(s):  
Degrees Of Freedom ◽  
Proof Mass ◽  
Vibration Modes ◽  
Electrode Structure ◽  
Element Analysis ◽  
Mechanical Coupling ◽  
Fully Differential ◽  
Mode Effects ◽  
The Finite Element Analysis ◽  
Cross Axis

In this paper, we report on a SOI-based comb capacitive-type accelerometer that senses acceleration in two lateral directions. The structure of the accelerometer was designed using a proof mass connected by four folded-beam springs, which are compliant to inertial displacement causing by attached acceleration in the two lateral directions. At the same time, the folded-beam springs enabled to suppress cross-talk causing by mechanical coupling from parasitic vibration modes. The differential capacitor sense structure was employed to eliminate common mode effects. The design of gap between comb fingers was also analyzed to find an optimally sensing comb electrode structure. The design of the accelerometer was carried out using the finite element analysis. The fabrication of the device was based on SOI-micromachining. The characteristics of the accelerometer have been investigated by a fully differential capacitive bridge interface using a sub-fF switched-capacitor integrator circuit. The sensitivities of the accelerometer in the two lateral directions were determined to be 6 and 5.5 fF/g, respectively. The cross-axis sensitivities of the accelerometer were less than 5%, which shows that the accelerometer can be used for measuring precisely acceleration in the two lateral directions. The accelerometer operates linearly in the range of investigated acceleration from 0 to 4g. The proposed accelerometer is expected for low-g applications.

scholarly journals Active Disturbance Rejection for a Three Degrees of Freedom Gyroscope

2018 ◽  
Vol 51 (13) ◽  
pp. 372-377 ◽  
Author(s):  
Juan E. Andrade García ◽  
Alejandra Ferreira de Loza ◽  
Luis T. Aguilar ◽  
Ramón I. Verdés
Keyword(s):  
Disturbance Rejection ◽  
Degrees Of Freedom ◽  
Active Disturbance Rejection ◽  
Three Degrees Of Freedom
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