Developing an Optimized Low-Cost Transtibial Energy Storage and Release Prosthetic Foot Using Three-Dimensional Printing

2020 ◽  
Vol 3 (2) ◽  
Author(s):  
Hisham Kamel ◽  
Omar Harraz ◽  
Khaled Azab ◽  
Tamer Attia
Keyword(s):  
Energy Storage ◽  
Low Cost ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Healthy Person ◽  
Metabolic Energy ◽  
Normal Person ◽  
Fe Model ◽  
Prosthetic Foot ◽  
Human Foot

Abstract This paper presents the results of an investigative study on the development of an affordable and functional prosthetic foot for below knee amputees. A prototype was successfully manufactured using three-dimensional (3D) printing technology. This continuously evolving technology enables the rapid production of prosthetics that are individually customized for each patient. Our prototype was developed after conducting a topology optimization study that interestingly converged to the shape of the biological human foot. Afterward, a design was envisioned where a simple energy storage and release (ESAR) mechanism was implemented to replace the Achilles tendon, which minimizes the metabolic energy cost of walking. Our mechanism can successfully manage 70% of the energy compared to a normal person during each walking step. A finite element (FE) model of the prosthetic was developed and validated using experimental tests. Then, this FE model was used to confirm the safe operation of the prosthetic through simulating different loading scenarios according to the ISO standard. A prototype was successfully tested by a healthy person using an adapter that was designed and 3D printed for this purpose. Our study clearly showed that customizable prosthetics could be produced at a fraction 1/60 of the cost of the commercially sold ones.

Developing a Cost-Effective and Functional Prosthetic Foot for Below Knee Amputees Using Topology Optimization and 3D Printing

2019 ◽  
Author(s):  
Hisham Kamel ◽  
Omar Harraz ◽  
Tamer Attia
Keyword(s):  
Topology Optimization ◽  
3D Printing ◽  
Experimental Tests ◽  
Cost Effective ◽  
Metabolic Energy ◽  
Release Mechanism ◽  
Normal Person ◽  
Fe Model ◽  
Prosthetic Foot ◽  
Human Foot

Abstract This paper presents the results of an investigative study on the development of an affordable and functional prosthetic foot for below knee amputees. A prototype was successfully manufactured using 3D printing technology. This continuously evolving technology enables the rapid production of prosthetics that are individually customized for each patient. Our prototype was developed after conducting a topology optimization study that interestingly converged to the shape of the biological human foot. Afterwards, a design was envisioned where a simple energy storage and release mechanism was implemented to replace the Achilles tendon, which minimizes the metabolic energy cost of walking. Our mechanism can successfully manage 70% of the energy compared to a normal person during each walking step. A finite element (FE) model of the prosthetic was developed and validated using experimental tests. Then, this FE model was used to confirm the safe operation of the prosthetic through simulating different loading scenarios according to the ISO standard. Our study clearly showed that customizable prosthetics could be produced at a fraction 1/60 of the cost of the commercially sold ones.

scholarly journals Numerical Analysis of the Perforated Steel Sheets Under Uni-Axial Tensile Force

Metals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 632 ◽  
Author(s):  
Ahmed M. Sayed
Keyword(s):  
Load Capacity ◽  
Tensile Force ◽  
Three Dimensional ◽  
Tensile Load ◽  
Experimental Tests ◽  
Strain Engineering ◽  
Uniaxial Tensile ◽  
Fe Model ◽  
Stress Strain ◽  
Steel Sheets

The perforated steel sheets have many uses, so they should be studied under the influence of the uniaxial tensile load. The presence of these holes in the steel sheets certainly affects the mechanical properties. This paper aims at studying the behavior of the stress-strain engineering relationships of the perforated steel sheets. To achieve this, the three-dimensional finite element (FE) model is mainly designed to investigate the effect of this condition. Experimental tests were carried out on solid specimens to be used in the test of model accuracy of the FE simulation. Simulation testing shows that the FE modeling revealed the ability to calculate the stress-strain engineering relationships of perforated steel sheets. It can be concluded that the effect of a perforated rhombus shape is greater than the others, and perforated square shape has no effect on the stress-strain engineering relationships. The efficiency of the perforated staggered or linearly distribution shapes with the actual net area on the applied loads has the opposite effect, as it reduces the load capacity for all types of perforated shapes. Despite the decrease in load capacity, it improves the properties of the steel sheets.

An Experimental and Numerical Study on the Axial Compression Response of Flexible Pipes

2010 ◽  
Author(s):  
Jose´ Renato M. de Sousa ◽  
Paula F. Viero ◽  
Carlos Magluta ◽  
Ney Roitman
Keyword(s):  
Axial Compression ◽  
Failure Modes ◽  
Mechanical Response ◽  
Numerical Study ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Mechanical Analysis ◽  
Fe Model ◽  
Flexible Pipe ◽  
Flexible Pipes

This paper deals with a nonlinear three-dimensional finite element (FE) model capable of predicting the mechanical response of flexible pipes subjected to axisymmetric loads focusing on their axial compression response. Moreover, in order to validate this model, experimental tests carried out at COPPE/UFRJ are also described. In these tests, a typical 4″ flexible pipe was subjected to axial compression until its failure is reached. Radial and axial displacements were measured and compared to the model predictions. The good agreement between all obtained results points that the proposed FE model is efficient to estimate the response of flexible pipes to axial compression and, furthermore, has potential to be employed in the identification of the failure modes related to excessive axial compression as well as in the mechanical analysis of flexible pipes under other types of loads.

scholarly journals Low-Cost and High-Productivity Three-Dimensional Nanocapacitors Based on Stand-Up ZnO Nanowires for Energy Storage

2016 ◽  
Vol 11 (1) ◽  
Author(s):  
Lei Wei ◽  
Qi-Xuan Liu ◽  
Bao Zhu ◽  
Wen-Jun Liu ◽  
Shi-Jin Ding ◽  
...  
Keyword(s):  
Energy Storage ◽  
Low Cost ◽  
Three Dimensional ◽  
Zno Nanowires ◽  
High Productivity

Simple method to construct three-dimensional porous carbon for electrochemical energy storage

Nanoscale ◽  
2018 ◽  
Vol 10 (33) ◽  
pp. 15842-15853 ◽  
Author(s):  
Huanhuan Wei ◽  
Kexuan Liao ◽  
Penghui Shi ◽  
Jinchen Fan ◽  
Qunjie Xu ◽  
...  
Keyword(s):  
Energy Storage ◽  
Porous Carbon ◽  
Carbon Materials ◽  
Low Cost ◽  
Three Dimensional ◽  
Electrochemical Energy Storage ◽  
Superabsorbent Polymer ◽  
Simple Method ◽  
Electrochemical Energy

A material derived from a nitrogen-enriched superabsorbent polymer in waste diapers provides a new basis for obtaining low-cost carbon materials.

Development and Validation of Finite Element Structure-Tuned Liquid Damper System Models

2015 ◽  
Vol 137 (11) ◽  
Author(s):  
Islam M. Soliman ◽  
Michael J. Tait ◽  
Ashraf A. El Damatty
Keyword(s):  
Finite Element ◽  
3D Structure ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Random Excitation ◽  
System Model ◽  
Fe Model ◽  
Tuned Liquid Damper ◽  
Supplemental Damping ◽  
Sensitive Structure

Implementation of supplemental damping systems (e.g., the dynamic vibration absorbers (DVAs)) to mitigate excessive tall building vibrations induced by external dynamic loads (wind storms or earthquakes) has increased over the last several decades. A tuned liquid damper (TLD) is a specific type of the DVAs that consists of a rigid tank which is partially filled with a liquid, usually water. The sloshing liquid inside the tank provides inertia forces that counteract the forces acting on the structure, thus reducing the building motion. A single sway mode of vibration is usually targeted, however, for certain structures multiple modes may need to be suppressed. Moreover, the location of the TLD on the floor plate is important for certain modes, such as a torsionally dominate mode. In this paper, a three-dimensional (3D) finite element (FE) structure-TLD system model (3D-structure-TLD) is proposed where the TLDs can be positioned at any location on the structure allowing the most effective positions in reducing the structure's dynamic response to be determined. Therefore, the response of a 3D structure (tower, high-rise building, bridge, etc.) fitted with single or multiple TLD(s) and subjected to dynamic excitation can be predicted using the proposed FE model. For torsionally sensitive structure (eccentric/irregular structures), this type of 3D numerical analysis is highly recommended. Two nonlinear TLD models are employed to simulate the TLD and implemented in the FE model. The 3D-structure-TLD system model is validated for the cases of sinusoidal and random excitation forces using existing experimental test values. Results from the 3D-structure-TLD system model are found to be in excellent agreement with values obtained from experimental tests.

A Method to Improve Prosthesis Leg Design Based on Pressure Analysis at the Socket-Residual Limb Interface

2016 ◽  
Author(s):  
Giorgio Colombo ◽  
Claudio Comotti ◽  
Davide Felice Redaelli ◽  
Daniele Regazzoni ◽  
Caterina Rizzi ◽  
...  
Keyword(s):  
Low Cost ◽  
Experimental Tests ◽  
Fe Model ◽  
Residual Limb ◽  
Pressure System ◽  
Pressure Distributions ◽  
Physical Prototype ◽  
Lower Limb Prosthesis ◽  
Loading Tests ◽  
Pressure Analysis

This paper presents a methodology and tools to improve the design of lower limb prosthesis through the measurement of pressure analysis at the interface residual limb-socket. The steps of the methodology and the design tools are presented using a case study focused on a transfemoral (amputation above knee) male amputee. The experimental setup based on F-Socket Tekscan pressure system is described as well the results of some static loading tests. Pressure data are visualized with a colour pressure map over the 3D model of the residual limb acquired using an optical low cost scanner, based on MS Kinect. Previous methodology is useful to evaluate a physical prototype; in order to improve also conceptual design, the Finite Element (FE) Analysis has been carried and results reached so far have been compared with experimental tests. Pressure distributions are comparable, even if some discrepancies have been highlighted due to sensors placements and implemented FE model. Future developments have been identified in order to improve the accuracy of the numerical simulations.

Equivalent Layer Approaches to Predict the Bisymmetric Hydrostatic Collapse Strength of Flexible Pipes

2018 ◽  
Author(s):  
José Renato M. de Sousa ◽  
Marcelo K. Protasio ◽  
Luis V. S. Sagrilo
Keyword(s):  
Three Dimensional ◽  
Experimental Tests ◽  
Fe Model ◽  
Flexible Pipe ◽  
Collapse Mechanisms ◽  
Collapse Strength ◽  
Flexible Pipes ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Radial Loading

The hydrostatic collapse strength of a flexible pipe is largely dependent on the ability of its carcass and pressure armor to resist radial loading and, therefore, its prediction involves an adequate modeling of these layers. Hence, initially, this work proposes a set of equations to estimate equivalent thicknesses and physical properties for these layers, which allows their modeling as equivalent orthotropic cylinders. These equations are obtained by simulating several two-point static ring tests with a three-dimensional finite element (FE) model based on beam elements and using these results to form datasets that are analyzed with a symbolic regression (SR) tool. The results of these analyses are the closed-form equations that best fit the provided datasets. After that, these equations are used in conjunction with a three-dimensional shell FE model and a previously presented analytical model to study the dry and wet hydrostatic collapse mechanisms of a flexible pipe. The predictions of these models agreed quite well with the collapse pressures obtained in experimental tests thus indicating that the use of the equivalent approach is promising.

Improvements on the Numerical Analysis of the Coupled Extensional–Torsional Response of a Flexible Pipe

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Héctor E. M. Muñoz ◽  
José R. M. de Sousa ◽  
Carlos Magluta ◽  
Ney Roitman
Keyword(s):  
Cross Sections ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Axial Rotation ◽  
Nonlinear Finite Element ◽  
Analytical Models ◽  
Fe Model ◽  
Flexible Pipe ◽  
Torsional Response ◽  
Axial Twist

In this paper, the coupled extensional–torsional behavior of a 4 in. flexible pipe is studied. The pipe is subjected to pure tension and two different boundary conditions are considered: ends free and prevented from axially rotating. The response of the pipe is predicted with a three-dimensional nonlinear finite element (FE) model. Some aspects of the obtained results are discussed, such as the effect of restraining the axial rotation at the extreme sections of the model; the effect of friction or adhesion between the layers of the pipe on the induced axial rotation (or torque) and elongation; and the reduction to simple plane behavior usually assumed by analytical models. The numerical results are compared to the ones measured in experimental tests. Reasonable agreement is observed between all results pointing out that the analyzed pipe is torque balanced and that friction mainly affects the axial twist induced by the applied tension. Moreover, the cross sections of the pipe remain straight with the imposed load, but different axial rotations are found in each layer.

An Experimental and Numerical Study on the Axial Compression Response of Flexible Pipes

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
José Renato M. de Sousa ◽  
Paula F. Viero ◽  
Carlos Magluta ◽  
Ney Roitman
Keyword(s):  
Axial Compression ◽  
Failure Modes ◽  
Mechanical Response ◽  
Numerical Study ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Mechanical Analysis ◽  
Fe Model ◽  
Flexible Pipe ◽  
Flexible Pipes

This paper deals with a nonlinear three-dimensional finite element (FE) model capable of predicting the mechanical response of flexible pipes subjected to axisymmetric loads focusing on their axial compression response. Moreover, in order to validate this model, experimental tests are also described. In these tests, a typical 4 in. flexible pipe was subjected to axial compression until its failure is reached. Radial and axial displacements were measured and compared to the model predictions. The good agreement between all results points out that the proposed FE model is effective to estimate the response of flexible pipes to axial compression and; furthermore, has potential to be employed in the identification of the failure modes related to excessive axial compression as well as in the mechanical analysis of flexible pipes under other types of loads.

Sign in / Sign up

Export Citation Format

Share Document