Periodic tilings and auxetic deployments

2020 ◽  
pp. 108128652094811
Author(s):  
Ciprian S Borcea ◽  
Ileana Streinu
Keyword(s):  
Configuration Space ◽  
Structural Design ◽  
Degrees Of Freedom ◽  
Materials Science ◽  
Arbitrary Dimension ◽  
Geometric Characteristics ◽  
Global Configuration ◽  
Local Properties ◽  
Three Degrees Of Freedom

We investigate geometric characteristics of a specific planar periodic framework with three degrees of freedom. While several avatars of this structural design have been considered in materials science under the name of chiral or missing rib models, all previous studies have addressed only local properties and limited deployment scenarios. We describe the global configuration space of the framework and emphasize the geometric underpinnings of auxetic deformations. Analogous structures may be considered in arbitrary dimension.

Design and calibration experiment of serial–parallel hybrid rotary platform with three degrees of freedom

2018 ◽  
Vol 233 (5) ◽  
pp. 1807-1817
Author(s):  
Yundou Xu ◽  
Suhuan Ni ◽  
Bei Wang ◽  
Zengzhao Wang ◽  
Jiantao Yao ◽  
...  
Keyword(s):  
Structural Design ◽  
Degrees Of Freedom ◽  
Motion Controller ◽  
Kinematic Parameters ◽  
Prototype Development ◽  
Calibration Experiment ◽  
Parallel Hybrid ◽  
Rotary Platform ◽  
Heavy Loads ◽  
Three Degrees Of Freedom

A new hybrid rotary platform with three degrees of freedom that possesses both a large workspace and the ability to bear heavy loads is presented. The degrees of freedom and rotary characteristics of the hybrid rotary platform are analyzed, and its solution of inverse position is obtained. The dimensional optimization, structural design, and prototype development of the hybrid rotary platform were carried out, an electrical control system based on a multi-axis motion controller and a three-axis gyroscope was developed, and a calibration experiment on the hybrid rotary platform was performed. After the key kinematic parameters were calibrated, the overall accuracy of the hybrid rotary platform greatly improved.

Serial Chain of Rigid Origami That Extends, Bends and Turns

2021 ◽  
Author(s):  
Haruto Kamijo ◽  
Tomohiro Tachi
Keyword(s):  
Configuration Space ◽  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Geometric Construction ◽  
Circular Arc ◽  
Flat Sheet ◽  
Serial Chain ◽  
Input Parameters ◽  
Arc Shape ◽  
Three Degrees Of Freedom

Abstract This paper presents a family of serial chain mechanisms with three degrees of freedom (DOF) by concatenating rigid origami modules. This chained mechanism forms a circular arc shape and can continuously extend, bend, and turn. The mechanism keeps three-DOF regardless of the number of connected modules, and the whole motion can be controlled by determining the configuration of one module at the end. We first describe the geometric construction of the mechanism and its implementation as a rigid origami fabricated from a flat sheet. We then analyze the kinematics of the system to illustrate the configuration space and how the shapes change by manipulating the input parameters. We also synthesize the motions by numerically solving inverse kinematics of the system. We also propose novel torus mechanism with two DOF.

scholarly journals Structural Design of Industrial Robot

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Tongbo Jiang
Keyword(s):  
Structural Design ◽  
Degrees Of Freedom ◽  
Industrial Robot ◽  
Stepper Motor ◽  
Motor Drive ◽  
Main Function ◽  
Robot Arm ◽  
Toothed Belt ◽  
Motor Drive System ◽  
Three Degrees Of Freedom

The robot is a planar joint robot composed of three degrees of freedom. Its main function is to carry out the handlingand movement of precision instruments and objects. Because of the small size, simple transmission principle, iswidely used in the electrical and electronic industry, household appliances, precision machinery industry and otherfi elds. The whole system consists of robot, robot arm, joint, stepper motor drive system and so on. Through the degreeof freedom of the stepper motor drive, complete the robot, the robot arm position changes. Specifi c design content:synchronous toothed belt drive design, screw nut design, the output shaft and shell design, stepper motor selection.On the basis of checking the strength of the structure, we optimize the structure of the robot.

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

scholarly journals Cyclic Deformation of Microcantilevers Using In-Situ Micromanipulation

2021 ◽  
Author(s):  
A. H. S. Iyer ◽  
M. H. Colliander
Keyword(s):  
Degrees Of Freedom ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Structural Components ◽  
Cyclic Testing ◽  
Phase Boundaries ◽  
Bulk Specimen ◽  
Arbitrary Position ◽  
Three Degrees Of Freedom

Abstract Background The trend in miniaturisation of structural components and continuous development of more advanced crystal plasticity models point towards the need for understanding cyclic properties of engineering materials at the microscale. Though the technology of focused ion beam milling enables the preparation of micron-sized samples for mechanical testing using nanoindenters, much of the focus has been on monotonic testing since the limited 1D motion of nanoindenters imposes restrictions on both sample preparation and cyclic testing. Objective/Methods In this work, we present an approach for cyclic microcantilever bending using a micromanipulator setup having three degrees of freedom, thereby offering more flexibility. Results The method has been demonstrated and validated by cyclic bending of Alloy 718plus microcantilevers prepared on a bulk specimen. The experiments reveal that this method is reliable and produces results that are comparable to a nanoindenter setup. Conclusions Due to the flexibility of the method, it offers straightforward testing of cantilevers manufactured at arbitrary position on bulk samples with fully reversed plastic deformation. Specific microstructural features, e.g., selected orientations, grain boundaries, phase boundaries etc., can therefore be easily targeted.

scholarly journals Galloping Stability and Wind Tunnel Test of Iced Quad Bundled Conductors considering Wake Effect

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Xiaohui Liu ◽  
Ming Zou ◽  
Chuan Wu ◽  
Mengqi Cai ◽  
Guangyun Min ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Transmission Lines ◽  
Degrees Of Freedom ◽  
Wind Tunnel Test ◽  
Aerodynamic Coefficients ◽  
Wake Effect ◽  
Aerodynamic Coefficient ◽  
Set Up ◽  
The Stability ◽  
Three Degrees Of Freedom

A new quad bundle conductor galloping model considering wake effect is proposed to solve the problem of different aerodynamic coefficients of each subconductor of iced quad bundle conductor. Based on the quasistatic theory, a new 3-DOF (three degrees of freedom) galloping model of iced quad bundle conductors is established, which can accurately reflect the energy transfer and galloping of quad bundle conductor in three directions. After a series of formula derivations, the conductor stability judgment formula is obtained. In the wind tunnel test, according to the actual engineering situation, different variables are set up to accurately simulate the galloping of iced quad bundle conductor under the wind, and the aerodynamic coefficient is obtained. Finally, according to the stability judgment formula of this paper, calculate the critical wind speed of conductor galloping through programming. The dates of wind tunnel test and calculation in this paper can be used in the antigalloping design of transmission lines.

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