scholarly journals Geometry Optimisation of a Hall-Effect-Based Soft Fingertip for Estimating Orientation of Thin Rectangular Objects

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 4056 ◽  
Author(s):  
Rosle ◽  
Wang ◽  
Hirai
Keyword(s):  
Hall Effect ◽  
Element Model ◽  
Object Orientation ◽  
Parameter Design ◽  
Average Error ◽  
Trial And Error ◽  
Tactile Sensors ◽  
Design Variables ◽  
Machine Learning Approach ◽  
The Finite Element Model

Soft tactile sensors have been applied to robotic grippers for assembly. It is a challenging task to obtain contact information and object orientation using tactile sensors during grasping. Currently, the design of Hall-effect-based tactile sensors to perform such tasks is based on trial and error. We present a method of investigating the optimal geometrical design of a cylindrical soft sensor to increase its sensitivity. The finite element model of a soft fingertip was constructed in Abaqus with two design variables, i.e., hollow radius and magnet position. Then, the model was imported into Isight, with the maximisation of magnet displacement as the objective function. We found that the optimal design was at the boundary of the parameter design space. Four fingertips were fabricated with one intuitive, one optimal, and two optional sets of parameters. Experiments were performed, and object orientation was estimated by utilising linear approximation and a machine learning approach. Good agreements were achieved between optimisation and experiments. The results revealed that the estimated average error in object orientation was decreased by the optimised fingertip design. Furthermore, the 3-axis forces could successfully be estimated based on sensor outputs.

Material Characteristic for Capability Analysis of Solid Tire by Finite Element Method

2018 ◽  
Vol 777 ◽  
pp. 416-420
Author(s):  
Juthanee Phromjan ◽  
Chakrit Suvanjumrat
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Element Model ◽  
Average Error ◽  
Element Analysis ◽  
Compression Load ◽  
Stress Strain Relation ◽  
The Finite Element Analysis ◽  
Capability Analysis ◽  
The Finite Element Model

The natural rubber compound of each layer of solid tire had determined the mechanical properties in tension. It was found that the stress-strain relation of each material tire layer was fitted very well with the Ogden constitutive model. The R2 which was 0.986, 0.996 and 0.985 represented the certain curve fitting on the internal, middle and tread layer of solid tire, respectively. Subsequently, the Ogden model was implemented in the finite element model of the rubber specimen and solid tire. The finite element analysis results obtained an average error of 18.00% and 14.63% for the specimen and solid tire model by comparing to the physical experiment, respectively. Particularly, the mechanical properties of the natural compounds could be used to predict the ultimate compression load for the solid tire failure.

scholarly journals Evaluation of Machine Learning Methods for Monitoring the Health of Guyed Towers

Sensors ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 213
Author(s):  
Diana Marcela Martinez Ricardo ◽  
German Efrain Castañeda Jimenez ◽  
Janito Vaqueiro Ferreira ◽  
Euripedes Guilherme de Oliveira Nobrega ◽  
Eduardo Rodrigues de Lima ◽  
...  
Keyword(s):  
Machine Learning ◽  
Service Failure ◽  
Failure Detection ◽  
Weather Conditions ◽  
Element Model ◽  
Machine Learning Approach ◽  
Different Types ◽  
Sensor Signals ◽  
Tower Vibration ◽  
The Finite Element Model

This paper presents the development of a methodology to detect and evaluate faults in cable-stayed towers, which are part of the infrastructure of Brazil’s interconnected electrical system. The proposed method increases system reliability and minimizes the risk of service failure and tower collapse through the introduction of predictive maintenance methods based on artificial intelligence, which will ultimately benefit the end consumer. The proposed signal processing and interpretation methods are based on a machine learning approach, where the tower vibration is acquired from accelerometers that measure the dynamic response caused by the effects of the environment on the towers through wind and weather conditions. Data-based models were developed to obtain a representation of health degradation, which is primarily based on the finite element model of the tower, subjected to wind excitation. This representation is also based on measurements using a mockup tower with different types of provoked degradation that was subjected to ambient changes in the laboratory. The sensor signals are preprocessed and submitted to an autoencoder neural network to minimize the dimensionality of the resources involved, being analyzed by a classifier, based on a Softmax configuration. The results of the proposed configuration indicate the possibility of early failure detection and evolution evaluation, providing an effective failure detection and monitoring system.

scholarly journals Verification and Validation of Supersonic Flutter of Rudder Model for Experiment

2021 ◽  
Author(s):  
Ju Qiu ◽  
Chaofeng Liu
Keyword(s):  
Finite Element ◽  
Optimization Technique ◽  
Wind Tunnel Test ◽  
Ground Vibration ◽  
Element Model ◽  
Experimental Information ◽  
Design Variables ◽  
Potential Applications ◽  
Supersonic Flutter ◽  
The Finite Element Model

The abrupt and explosive nature of flutter is a dangerous failure mode, which is closely related to the structural modes. In this work, the principal goal of the study is to produce the model, which is used very accurately for flutter predictions. Mode correctness of the model can correct the test deflects by the optimization technique----Sequential Quadratic Programming (SQP). The optimization of two finite element models for two flight conditions, transonic and supersonic speeds, had the different objectives which were defined by the nonlinear and linear eigenvector errors. The first and second frequencies were taken as constraints. And the stiffness of the rotation shaft was also restricted to some limits. The stiffness of the rudder axle was defined as design variables. Experiments were performed for considering springs both in plunge and in torsion of the rudder shaft. When the comparison between experimental information and analyzed calculations is described, generally excellent agreement is obtained between experimental and calculated results, and aeroelastic instability is predicted that agrees with experimental observations. Comments are also given concerning improvements of the flutter speed to be made to the model with changing stiffness of the rudder axle. Most importantly, V&V Method is used to provide the confidence in the results from simulation in this paper. Firstly, it introduces experimental data from Ground Vibration Test to build up or modify the Finite Element Model, during the Verification phase, which makes simulated models closer to the real world and guarantees satisfaction of final computed results to requirements, such as airworthiness. Secondly, the flutter consequence is validated by wind tunnel test. These enhancements could find potential applications in industrial problems.

Topological Optimization Design of Cistern Stents of the Planomiller Machine Based on Hyperworks

2011 ◽  
Vol 421 ◽  
pp. 423-426
Author(s):  
Fu Yun Liu ◽  
Ying Sun ◽  
Tian Chao Yu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Optimization Design ◽  
Element Model ◽  
Topological Optimization ◽  
Structural Deformation ◽  
Engineering Practice ◽  
Geometry Model ◽  
Design Variables ◽  
The Finite Element Model

Planomiller is a milling machine that widely used in processes of large parts. Cistern stents is a component of planomiller supporting the sink. In this paper, topological optimization of Cistern stents is implemented to reduce its weight. Firstly geometry model of Cistern stents is built in SolidWorks, a finite element model of Cistern stents is established. Then loads and boundary conditions are loaded to the finite element model according to engineering practice. Finally density of units is set as the design variables, energy of structural deformation is set as the objective function, Cistern stents can be optimized by optimizing analysis. The compared results show that the proposed optimization design is effective.

scholarly journals Updating the finite element model of a Colombian Bridge with Ansys

DYNA ◽  
2020 ◽  
Vol 87 (212) ◽  
pp. 209-218
Author(s):  
Diego Sequera Gutierrez ◽  
Luis Felipe Solano Rodríguez ◽  
Edgar Eduardo Muñoz Díaz ◽  
Yezid Alexander Alvarado Vargas ◽  
Jesús Daniel Villalba Morales ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Structural Model ◽  
Natural Frequencies ◽  
Element Model ◽  
Ambient Vibration ◽  
Normal Operation ◽  
Design Variables ◽  
Ambient Vibration Measurements ◽  
The Finite Element Model

Updating structural model is a knowledge field that have been studied in the last decades to guarantee the reliability on the model defined to represent the behavior of a structure, but generally implies the use of different software to carry out the different parts of the process. This paper presents the updating of the finite element model of a curve-alignment reinforced concrete bridge located near to the city of Ubaté in Colombia by using the optimization tool available in software Ansys and ambient vibration measurements. The use of such type of information avoids to carry out forced-vibration test, which affect the normal operation of the bridge. The objective function corresponds to the minimization of the error between analytical and experimental natural frequencies of the bridge. The design variables correspond to the material properties of the concrete and the elastomeric bearings. Results show that the error was decreased to less than 2%. The sensibility analysis allowed to determine which variables are more sensible to affect the natural frequencies in the structure.

scholarly journals Optimal design and simulation of compliant mechanism used as amplifier of micro linear actuator

2017 ◽  
Vol 20 (K5) ◽  
pp. 5-12
Author(s):  
Khien Van Nguyen ◽  
Phuong Nam Ngo ◽  
Hoang Huy Pham ◽  
Tuan Huy Pham
Keyword(s):  
Optimal Design ◽  
Compliant Mechanism ◽  
Element Model ◽  
Linear Actuator ◽  
Analysis Tool ◽  
Amplification Ratio ◽  
Design Variables ◽  
Compliant Mechanism Design ◽  
The Finite Element Model ◽  
Ansys Workbench

This paper presents the design of a compliant mechanism that can be used as an amplifier mechanism of the micro linear actuator. The design includes the synthesis of pseudo rigid-body mechanism, the converting rigid mechanism to a compliant mechanism, the parameterization of dimensions of compliant mechanism, design variables' choice and the optimal design using ANSYS optimization tool. In addition, the paper also describes the use of response surface analysis tool of ANSYS Workbench to evaluate the effect of design variables on the optimization so that to investigate the sensitivity of those design variables on the objective function. The finite element model of the designed mechanism is established and used to simulate the compliant mechanism and to evaluate the amplification ability. The results show that the amplification ratio is higher than 10.

Redrawing Operation a Star Shape from Cylindrical Shape Using Experimental and FE Analysis

2020 ◽  
Vol 38 (1A) ◽  
pp. 25-32
Author(s):  
Waleed Kh. Jawad ◽  
Ali T. Ikal
Keyword(s):  
Finite Element ◽  
Effective Strain ◽  
Element Model ◽  
Cylindrical Shape ◽  
Element Analysis ◽  
Punch Force ◽  
Maximum Value ◽  
Element Simulation ◽  
Blank Sheet ◽  
The Finite Element Model

The aim of this paper is to design and fabricate a star die and a cylindrical die to produce a star shape by redrawing the cylindrical shape and comparing it to the conventional method of producing a star cup drawn from the circular blank sheet using experimental (EXP) and finite element simulation (FES). The redrawing and drawing process was done to produce a star cup with the dimension of (41.5 × 34.69mm), and (30 mm). The finite element model is performed via mechanical APDL ANSYS18.0 to modulate the redrawing and drawing operation. The results of finite element analysis were compared with the experimental results and it is found that the maximum punch force (39.12KN) recorded with the production of a star shape drawn from the circular blank sheet when comparing the punch force (32.33 KN) recorded when redrawing the cylindrical shape into a star shape. This is due to the exposure of the cup produced drawn from the blank to the highest tensile stress. The highest value of the effective stress (709MPa) and effective strain (0.751) recorded with the star shape drawn from a circular blank sheet. The maximum value of lamination (8.707%) is recorded at the cup curling (the concave area) with the first method compared to the maximum value of lamination (5.822%) recorded at the cup curling (the concave area) with the second method because of this exposure to the highest concentration of stresses. The best distribution of thickness, strains, and stresses when producing a star shape by

A SIMPLIFIED ANALYTICAL PROCEDURE FOR SEISMIC ANALYSIS OF TIMBER LIGHT-FRAME SHEAR WALLS

2019 ◽  
Vol 3 (Special Issue on First SACEE'19) ◽  
pp. 173-180
Author(s):  
Giorgia Di Gangi ◽  
Giorgio Monti ◽  
Giuseppe Quaranta ◽  
Marco Vailati ◽  
Cristoforo Demartino
Keyword(s):  
Analytical Procedure ◽  
Seismic Analysis ◽  
Shear Walls ◽  
Element Model ◽  
Sensitivity Analyses ◽  
Width Ratio ◽  
Damping Factor ◽  
Equivalent Viscous Damping ◽  
Design Variables ◽  
Depth Analysis

The seismic performance of timber light-frame shear walls is investigated in this paper with a focus on energy dissipation and ductility ensured by sheathing-to-framing connections. An original parametric finite element model has been developed in order to perform sensitivity analyses. The model considers the design variables affecting the racking load-carrying capacity of the wall. These variables include aspect ratio (height-to-width ratio), fastener spacing, number of vertical studs and framing elements cross-section size. A failure criterion has been defined based on the observation of both the global behaviour of the wall and local behaviour of fasteners in order to identify the ultimate displacement of the wall. The equivalent viscous damping has been numerically assessed by estimating the damping factor which is in use in the capacity spectrum method. Finally, an in-depth analysis of the results obtained from the sensitivity analyses led to the development of a simplified analytical procedure which is able to predict the capacity curve of a timber light-frame shear wall.

Durability Analysis of the Reduction Gear for High Speed Train Considering Driving Histories

2012 ◽  
Vol 586 ◽  
pp. 269-273
Author(s):  
Chul Su Kim ◽  
Gil Hyun Kang
Keyword(s):  
Fatigue Life ◽  
High Speed ◽  
Element Model ◽  
Rolling Stock ◽  
Reduction Gear ◽  
High Speed Train ◽  
Analysis Software ◽  
Tractive Effort ◽  
Durability Analysis ◽  
The Finite Element Model

To assure the safety of the power bogies for train, it is important to perform the durability analysis of reduction gear considering a variation of velocity and traction motor capability. In this study, two types of applied load histories were constructed from driving histories considering the tractive effort and the train running curves by using dynamic analysis software (MSC.ADAMS). Moreover, this study was performed by evaluating fatigue damage of the reduction gears for rolling stock using durability analysis software (MSC.FATIGUE). The finite element model for evaluating the carburizing effect on the gear surface was used for predicting the fatigue life of the gears. The results showed that the fatigue life of the reduction gear would decrease with an increasing numbers of stops at station.

scholarly journals Effects of intracorneal ring segments implementation technique and design on corneal biomechanics and keratometry in a personalized computational analysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Niksa Mohammadi Bagheri ◽  
Mahmoud Kadkhodaei ◽  
Shiva Pirhadi ◽  
Peiman Mosaddegh
Keyword(s):  
Clinical Data ◽  
Three Dimensional ◽  
Element Model ◽  
Von Mises Stress ◽  
Patient Specific ◽  
Average Error ◽  
Constant Thickness ◽  
Arc Length ◽  
Implementation Techniques ◽  
Von Mises

AbstractThe implementation of intracorneal ring segments (ICRS) is one of the successfully applied refractive operations for the treatment of keratoconus (kc) progression. The different selection of ICRS types along with the surgical implementation techniques can significantly affect surgical outcomes. Thus, this study aimed to investigate the influence of ICRS implementation techniques and design on the postoperative biomechanical state and keratometry results. The clinical data of three patients with different stages and patterns of keratoconus were assessed to develop a three-dimensional (3D) patient-specific finite-element model (FEM) of the keratoconic cornea. For each patient, the exact surgery procedure definitions were interpreted in the step-by-step FEM. Then, seven surgical scenarios, including different ICRS designs (complete and incomplete segment), with two surgical implementation methods (tunnel incision and lamellar pocket cut), were simulated. The pre- and postoperative predicted results of FEM were validated with the corresponding clinical data. For the pre- and postoperative results, the average error of 0.4% and 3.7% for the mean keratometry value ($$\text {K}_{\text{mean}}$$ K mean ) were predicted. Furthermore, the difference in induced flattening effects was negligible for three ICRS types (KeraRing segment with arc-length of 355, 320, and two separate 160) of equal thickness. In contrast, the single and double progressive thickness of KeraRing 160 caused a significantly lower flattening effect compared to the same type with constant thickness. The observations indicated that the greater the segment thickness and arc-length, the lower the induced mean keratometry values. While the application of the tunnel incision method resulted in a lower $$\text {K}_{\text{mean}}$$ K mean value for moderate and advanced KC, the induced maximum Von Mises stress on the postoperative cornea exceeded the induced maximum stress on the cornea more than two to five times compared to the pocket incision and the preoperative state of the cornea. In particular, an asymmetric regional Von Mises stress on the corneal surface was generated with a progressive ICRS thickness. These findings could be an early biomechanical sign for a later corneal instability and ICRS migration. The developed methodology provided a platform to personalize ICRS refractive surgery with regard to the patient’s keratoconus stage in order to facilitate the efficiency and biomechanical stability of the surgery.

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