scholarly journals Design and Modeling of a Bio-Inspired Flexible Joint Actuator

Actuators ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 95
Author(s):  
Ming Xu ◽  
Cheng Rong ◽  
Long He
Keyword(s):  
Hydraulic System ◽  
Driving Forces ◽  
Theoretical Models ◽  
Element Analysis ◽  
Flexible Joint ◽  
Fea Model ◽  
The Finite Element Analysis ◽  
Series Of Experiments ◽  
The Mathematical Model ◽  
Moving Speed

Spiders rely on a hydraulic system to stretch their legs but use muscles to make their legs flex. The compound drive of hydraulics and muscle makes an integrate dexterous structure with powerful locomotion abilities, which perfectly meets the primary requirements of advanced robots. Inspired by this hydraulics-muscle co-drive joint, a novel flexible joint actuator was proposed and its driving characteristics were preliminarily explored. The bio-inspired flexible joint manifested as a double-constrained balloon actuator, which was fabricated by the composite process of 3D printing and casting. To evaluate its performance, the mathematical model was deduced, as well as the finite element analysis (FEA) model. A series of experiments on the rotation angles, driving forces, and efficiencies of the flexible joint were carried out and compared with the mathematical calculations and FEA simulations. The results show that the accuracy of the two theoretical models can be used to assess the joint actuator. The locomotion test of a soft arthropod robot with two flexible joints was also implemented, where the moving speed reached 22 mm/s and the feasibility of the proposed flexible joint applied to a soft robot was demonstrated.

Study on Asymmetrical Sheet Rolling by the Finite Element Method

1999 ◽  
Vol 15 (4) ◽  
pp. 149-155 ◽  
Author(s):  
Yeong-Maw Hwang ◽  
Dyi-Cheng Chen ◽  
Gow-Yi Tzou
Keyword(s):  
Finite Element ◽  
Rolling Force ◽  
Speed Ratio ◽  
Element Analysis ◽  
Sheet Rolling ◽  
Useful Knowledge ◽  
Pass Schedule ◽  
The Finite Element Analysis ◽  
Series Of Experiments ◽  
Roll Gap

AbstractAdopting the DEFORM software for the finite element analysis, this study simulated steady-state plastic deformation of the sheet at the roll-gap during asymmetrical sheet rolling. Using FEM code DEFORM, the effects of roll speed ratio, roll radius ratio, friction factor ratio upon the curvature of the rolled product and rolling force were systematically discussed. With a view to verifying the validity of the study simulated, a series of experiments on asymmetrical cold sheet rolling using Aluminum sheet as specimen are carried out. The comparisons between numerical and experimental results show good agreement. Therefore, this numerical model using DEFORM software can offer useful knowledge for designing the pass-schedule of asymmetrical sheet rolling.

The Analyse on Stiffness Model of 3-PPSR Flexible Parallel Robot

2014 ◽  
Vol 716-717 ◽  
pp. 1643-1647
Author(s):  
Yu Liang Luan ◽  
Wei Bin Rong ◽  
Li Ning Sun
Keyword(s):  
Finite Element ◽  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Parallel Robot ◽  
Force Balance ◽  
Element Analysis ◽  
Flexible Hinge ◽  
Stiffness Model ◽  
The Finite Element Analysis ◽  
The Mathematical Model

In order to achieve greater workspace motion, it’s designed a high aspect ratio 3-PPSR flexible parallel robot, driven by a piezoelectric motor, connected by flexible hinges, which has the advantages of simple structure, non singular, seamless, high motion precision. Because of the stiffness of the system directly affecting the motion accuracy, load bearing performance, according to the characteristics of high aspect ratio flexible hinge, It’s established the mathematical model of flexible hinge through finite element method. Using method of integral stiffness, conbined coordination equation with force balance equation, the flexible stiffness model of system is obtained. Finally, through using Ansys, it’s confirmed the validity of the theoretical model by comparing of the theoretical stiffness model results with the finite element analysis of the model results, to provide a reliable guarantee for optimization and analysis of kinematics and dynamics of flexible parallel robot.

Performance of Depressurization Devices to Dynamic Loads Generated by Arcing in Liquid Filled Transformers

2018 ◽  
Author(s):  
Ashwin Padmanaban Iyer ◽  
Anne Goj ◽  
Omar K. Ahmed
Keyword(s):  
Pressure Wave ◽  
Dynamic Performance ◽  
Sine Wave ◽  
Evaluation Methodology ◽  
Element Analysis ◽  
Loading Rates ◽  
Fea Model ◽  
The Finite Element Analysis ◽  
Rupture Disk ◽  
Dielectric Insulation

This study provides a methodology that can be used to evaluate the dynamic performance of fast depressurization devices used in liquid-filled oil transformers. Liquid-filled transformers are susceptible to explosions due to internal arcing if the dielectric insulation fails. The internal arc vaporizes a portion of the liquid and generates a sudden pressure wave. The first peak of the pressure wave has been measured to be as high as 13 bars, with time durations on the order of milliseconds [1]. Transformer tanks have a typical static withstand limit of approximately 1 bar gauge [2]. It is thus imperative that the tank be depressurized before the static pressure reaches such a threshold. One industry-accepted Fast Depressurization System [3] used to depressurize transformers after an internal arc is based on a patented rupture disk design [4]. This study compares the dynamic performance of this disk to results from a successful test campaign using a rupture disk as the depressurization device. Limiting loading rate values from the test campaign are then used to comment on the effectiveness of the design. The evaluation methodology is based on Pressure-Impulse (P-I) curves. The P-I curve was generated by running a series of Implicit Dynamic analysis using Code_Aster [5]. This iterative process first required establishing a failure mode that is consistent with actual observed failure in the field and observable in the Finite Element Analysis (FEA) model. The criteria were then used in interpreting the response of the Rupture Disk to a series of different half-sine wave pulse loading of varying amplitudes and time-periods. The generated P-I curve was then compared to loading rates observed in the test campaign [1] as well as three other higher loading rates (1.28 times, 2 times, 3.8 times, and 10.25 times the reported experimental rate) to qualitatively assess the effectiveness of the design. Results indicated that disk functions extremely effectively as a Fast Depressurization System as also corroborated by the test campaign. Although this methodology is used for the rupture disk, it is expected that this methodology can be extended to compare the dynamic performance of other depressurization devices.

Research on Loss and Temperature Rise of a Novel Dynamic Electromagnetic Induction Heater

2012 ◽  
Vol 468-471 ◽  
pp. 3108-3112
Author(s):  
Hai Du ◽  
Yan Bin Qu
Keyword(s):  
Electromagnetic Induction ◽  
Mechanical Energy ◽  
Heat Flux Distribution ◽  
Element Analysis ◽  
Operation Mechanism ◽  
Induction Heater ◽  
Copper Loss ◽  
Electromagnetic Field Theory ◽  
The Finite Element Analysis ◽  
The Mathematical Model

A novel dynamic electromagnetic induction heater for water treatment system is introduced in this paper, and its structure and operation mechanism is given. The heater converts input mechanical energy into various forms of heat energy completely, including the hyseresis loss, eddy current loss, copper loss and so on, and the mathematical model of loss is established based on fundamental electromagnetic field theory. By the finite element analysis, the above three kinds of loss are calculated at different rotation speed, as well as each of the percentage of total loss. At last, the temperature field and heat flux distribution of heater are calculated.

A CAD/CAE System for Structures of Dockside Container Cranes

2006 ◽  
Author(s):  
Chonghua Wang ◽  
Hua Li
Keyword(s):  
Integration Method ◽  
Parametric Model ◽  
Complex Structures ◽  
Element Analysis ◽  
Container Cranes ◽  
Fea Model ◽  
The Finite Element Analysis ◽  
Cad Cam ◽  
Cae System ◽  
Model Family

Dockside container cranes have huge complex structures which have various kinds of types and lots of parameters for design. Moreover the finite element analysis must be carried out on the structures. An integrated CAD/CAM system for crane’s structures is introduced in this paper. A CAD platform of 3D parametric model family is built to allow generation of feasible configurations of crane products. Using Visual C++ and the second exploiting software kit, an integration method of CAD/CAE which includes regeneration of 3D parametric model, synchronous updating and analysis of FEA model is achieved.

scholarly journals Damage Identification of Continuous Rigid Frame Concrete Bridge

2014 ◽  
Vol 8 (1) ◽  
pp. 193-200
Author(s):  
Shengnan Huang ◽  
Lieping Ye ◽  
Xinzheng Lu
Keyword(s):  
Damage Accumulation ◽  
Damage Identification ◽  
Concrete Bridge ◽  
Element Analysis ◽  
Fea Model ◽  
Rigid Frame ◽  
The Finite Element Analysis ◽  
Mode Method ◽  
Different Levels

During a bridge service life, many factors can cause damage accumulation such as overloaded traffic, fatigue effect, and so on. Hence, the identification of potential damages has been received wide attention to prevent such sudden fatal accident. An experiment of a continuous rigid frame concrete bridge, which had 3 spans and a total length of 18 meters, was presented in this paper. Two load stages and ten different load steps were simulated to test various scenario of long-term loading and different levels of overload. Curvature mode method was adopted to detect the damage during the exercises. The changes of curvature modes were used to detect damage after the ten load steps. This method performed excellent to identify the damage position of the bridge. So, it is concluded that the curvature modes can be used to detect damage in actual structures. In addition, the Finite-Element Analysis (FEA) was utilized, and the experimental recurring was verified positively through FEA model.

The Finite Element Analysis and Structure Optimizing of the 42MN Flatting Mill’s Higher Beam

2010 ◽  
Vol 145 ◽  
pp. 317-320
Author(s):  
Chun Ming Zhang ◽  
Run Yuan Hao
Keyword(s):  
Mathematical Model ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Structural Design ◽  
Structural Parameters ◽  
Element Model ◽  
Optimum Structure ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
The Mathematical Model

This text is on the basis of the investigation of the 42MN flatting mill’s higher beam, establishing the flatting mill’s higher beam’s finite element model and the mathematical model which has optimum structure. According to the results of their structure finite element analysis, weaved the relevant procedures and optimized them, obtained ideal structural parameters, this text provide better ideas and ways for the structural design of the flatting mill’s higher beam.

Characteristics of the Linear Piezoelectric Motor with Semi-Elliptical Stator

2013 ◽  
Vol 415 ◽  
pp. 122-125
Author(s):  
Shine Tzong Ho ◽  
Fu Jie Hu
Keyword(s):  
Finite Element ◽  
Sine Wave ◽  
Maximum Output ◽  
Driving Voltage ◽  
Piezoelectric Motor ◽  
Element Analysis ◽  
Output Force ◽  
Resonance Frequencies ◽  
The Finite Element Analysis ◽  
Moving Speed

A novel design of the semi-elliptical motor based on a double-mode type ultrasonic motor is proposed and analyzed in this paper. Due to the simplification, the semi-elliptical piezoelectric motor can be considered as an improvement of the elliptical piezoelectric motor which we have proposed in the past. The composite structure of the stator in the motor is formed by two multilayer piezoelectric actuators clamped in a semi-elliptical elastic body. In the simulation, finite element modeling of the motor is performed. The geometry of the stator has been computed with the help of the finite element analysis. Then, the dimensions of the stator's structure were determined by making the two resonance frequencies close to each other. In the experiments, the impedance and the displacement response are measured and discussed for understanding the characteristics of the linear piezoelectric motor with a semi-elliptical stator. The motor achieved maximum moving speed of 96 mm/s and the maximum output force of 0.64 N when applying a sine wave of 14Vr driving voltage at 21.2 kHz, while the maximum moving speed of 132 mm/s and the maximum output force of 0.88 N can be achieved if applying two signal driving method of the same voltage.

Analysis on Spindle of 2MW Wind Generator

2011 ◽  
Vol 121-126 ◽  
pp. 2532-2536
Author(s):  
Jia Hong Zheng ◽  
Min Li
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Element Model ◽  
Optimal Model ◽  
Optimization Analysis ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
The Mathematical Model ◽  
The Finite Element Model ◽  
Complete Optimization

The model of the spindle was made while the related characteristics and parameters were analysising,and then it was inducted in ANSYS finite element analysis software. Through carrying the constraint on the finite element model, the spindle was completed to realize the finite element analysis. At last, the model was inducted in MATLAB to establish the optimal model, through the mathematical model ,it was realised to complete optimization analysis.

Numerical Simulation of Thermal Conductivity of Particle Filled Epoxy Composites

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Jun Zeng ◽  
Renli Fu ◽  
Simeon Agathopoulos ◽  
Shaodong Zhang ◽  
Xiufeng Song ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Finite Element ◽  
Filler Content ◽  
Three Dimensional ◽  
Theoretical Models ◽  
Epoxy Composites ◽  
Numerical Estimation ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Three Dimensional Models

A finite element method was developed to predict the effective thermal conductivity of particle filled epoxy composites. Three-dimensional models, which considered the effect of filler geometry, filler aspect ratio, conductivity ratio of filler to matrix, and interfacial layer were used to simulate the microstructure of epoxy composites for various filler volume fractions up to 30%. The calculated thermal conductivities were compared with results from existing theoretical models and experiments. Numerical estimation of ellipsoids-in-cube model accurately predicted thermal conductivity of epoxy composites with alumina filler particles. The number of length division during mesh process and particle numbers used in the finite element analysis affect the accuracy of calculated results. At a given value of filler content, the numerical results indicated a ratio of conductivity of filler to matrix for achieving the maximum thermal conductivity.

Sign in / Sign up

Export Citation Format

Share Document