Evaluating Mobility Behavior of Fluid Filled Fiber-Reinforced Elastomeric Enclosures

2012 ◽  
Author(s):  
Girish Krishnan ◽  
Joshua Bishop-Moser ◽  
Charles Kim ◽  
Sridhar Kota
Keyword(s):  
Large Class ◽  
Power Density ◽  
Cost Effective ◽  
Design Tool ◽  
Preliminary Design ◽  
Fiber Reinforced ◽  
Soft Robots ◽  
Large Power ◽  
Mobility Behavior ◽  
Narrow Class

Fluid filled Fiber Reinforced Elastomeric Enclosures (FREE) have been popular choices for actuators in prosthetics and soft robots owing to their large power density and cost effective manufacturing. While a narrow class of FREEs known as McKibben’s actuators have been extensively studied, there is a wide unexplored class that could be potentially used as actuators and load bearing members. This paper analyzes the mobility of a large class of FREEs based on simple geometric relationships that originate due to the inextensibility of fibers and incompressibility of fluids. The analysis conducted on various families of fibers reveal certain configurations that are locked under fluidic actuation. Furthermore the analysis reveals unrestricted motion in certain directions (freedom) and restrictions in certain other directions (constraint). Such an analysis is deemed to be useful as a preliminary design tool to pick the appropriate geometry for use in design of soft robots and actuators.

scholarly journals A zonal safety analysis methodology for preliminary aircraft systems and structural design

2018 ◽  
Vol 122 (1255) ◽  
pp. 1330-1351 ◽  
Author(s):  
Z. Chen ◽  
J. P. Fielding
Keyword(s):  
Failure Modes ◽  
Hazard Analysis ◽  
Fault Tree Analysis ◽  
Cost Effective ◽  
Safety Analysis ◽  
Design Tool ◽  
Assessment Process ◽  
Design Stage ◽  
Preliminary Design

ABSTRACTZonal Safety Analysis (ZSA) is a major part of the civil aircraft safety assessment process described in Aerospace Recommended Practice 4761 (ARP4761). It considers safety effects that systems/items installed in the same zone (i.e. a defined area within the aircraft body) may have on each other. Although the ZSA may be conducted at any design stage, it would be most cost-effective to do it during preliminary design, due to the greater opportunity for influence on system and structural designs and architecture. The existing ZSA methodology of ARP4761 was analysed, but it was found to be more suitable for detail design rather than preliminary design. The authors therefore developed a methodology that would be more suitable for preliminary design and named it the Preliminary Zonal Safety Analysis (PZSA). This new methodology was verified by means of the use of a case study, based on the NASA N3-X project. Several lessons were learnt from the case study, leading to refinement of the proposed method. These lessons included focusing on the positional layout of major components for the zonal safety inspection, and using the Functional Hazard Analysis (FHA)/Fault Tree Analysis (FTA) to identify system external failure modes. The resulting PZSA needs further refinement, but should prove to be a useful design tool for the preliminary design process.

Evaluation of cost-effective hybrid fiber reinforced ECC

Sadhana ◽  
2021 ◽  
Vol 46 (2) ◽  
Author(s):  
Maninder Singh ◽  
Babita Saini ◽  
HD Chalak
Keyword(s):  
Cost Effective ◽  
Fiber Reinforced ◽  
Hybrid Fiber

Using CFD to Enhance the Preliminary Design of High-Pressure Steam Turbines

2013 ◽  
Author(s):  
Juri Bellucci ◽  
Federica Sazzini ◽  
Filippo Rubechini ◽  
Andrea Arnone ◽  
Lorenzo Arcangeli ◽  
...  
Keyword(s):  
High Pressure ◽  
Steam Turbine ◽  
Design Tool ◽  
Tip Clearance ◽  
Large Set ◽  
Preliminary Design ◽  
Steam Turbines ◽  
High Pressure Steam ◽  
Wide Range ◽  
Pressure Steam

This paper focuses on the use of the CFD for improving a steam turbine preliminary design tool. Three-dimensional RANS analyses were carried out in order to independently investigate the effects of profile, secondary flow and tip clearance losses, on the efficiency of two high-pressure steam turbine stages. The parametric study included geometrical features such as stagger angle, aspect ratio and radius ratio, and was conducted for a wide range of flow coefficients to cover the whole operating envelope. The results are reported in terms of stage performance curves, enthalpy loss coefficients and span-wise distribution of the blade-to-blade exit angles. A detailed discussion of these results is provided in order to highlight the different aerodynamic behavior of the two geometries. Once the analysis was concluded, the tuning of a preliminary steam turbine design tool was carried out, based on a correlative approach. Due to the lack of a large set of experimental data, the information obtained from the post-processing of the CFD computations were applied to update the current correlations, in order to improve the accuracy of the efficiency evaluation for both stages. Finally, the predictions of the tuned preliminary design tool were compared with the results of the CFD computations, in terms of stage efficiency, in a broad range of flow coefficients and in different real machine layouts.

Experimental evaluation on engineering properties and microstructure of the high-performance fiber-reinforced mortar with low polypropylene fiber content

2021 ◽  
Vol 72 (7) ◽  
pp. 824-840
Author(s):  
Hung Vu Viet ◽  
Cuong Nguyen Tuan ◽  
Duy Nguyen Huu ◽  
Tho Ngo Nguyen Ngoc ◽  
Phuoc Huynh Trong
Keyword(s):  
High Performance ◽  
Polypropylene Fiber ◽  
Cost Effective ◽  
Fiber Content ◽  
Engineering Properties ◽  
Fiber Reinforced ◽  
Cement Mortars ◽  
High Performance Fiber ◽  
New Construction ◽  
Local Materials

Recently, high-performance fiber-reinforced mortar/concrete (HPFRM) has been researched and developed in many fields such as repair, maintenance, and new construction of infrastructure works due to its high strain capacity and tight crack width characteristics. Optimizing the design of mixture proportions and structures using HPFRM is still a complex mechanical and physical process, depending on the design principles, specific site conditions, and their local materials. This study aims to develop an HPFRM with low polypropylene fiber content by using locally available ingredients in Southern Vietnam to address the deficiencies commonly observed in traditional cement grout mortars. Three mixture proportions were prepared with different water-to-binder (w/b) ratios of 0.2, 0.25, and 0.3. Then, the performance of HPFRM was evaluated in both fresh and hardened stages. Additionally, the microstructural characteristics of each mix design were also assessed through scanning electron microscope observation. The experimental results showed that the optimum w/b of 0.25 and a fixed dosage of 0.6% polypropylene fiber produced positive impacts on the rheological, mechanical properties, and also ductility of the high-performance mortar. It was concluded that HPFRMs are promising for cost-effective and sustainable cement mortars.

scholarly journals FEM Based Preliminary Design Optimization in Case of Large Power Transformers

2019 ◽  
Author(s):  
Tamás Orosz ◽  
David Pánek ◽  
Pavel Karban
Keyword(s):  
Design Optimization ◽  
Design Process ◽  
Optimization Problems ◽  
Optimization Method ◽  
Power Transformers ◽  
Design Stage ◽  
Preliminary Design ◽  
Large Power ◽  
Custom Made ◽  
Transformer Design

Since large power transformers are custom-made, and their design process is a labor-intensive task, their design process is split into different parts. In tendering, the price calculation is based on the preliminary design of the transformer. Due to the complexity of this task, it belongs to the most general branch of discrete, non-linear mathematical optimization problems. Most of the published algorithms are using a copper filling factor based winding model to calculate the main dimensions of the transformer during this first, preliminary design step. Therefore, these cost optimization methods are not considering the detailed winding layout and the conductor dimensions. However, the knowledge of the exact conductor dimensions is essential to calculate the thermal behaviour of the windings and make a more accurate stray loss calculation. The paper presents a novel, evolutionary algorithm-based transformer optimization method which can determine the optimal conductor shape for the windings during this examined preliminary design stage. The accuracy of the presented FEM method was tested on an existing transformer design. Then the results of the proposed optimization method have been compared with a validated transformer design optimization algorithm.

1D nanorod-like porous carbon with simultaneous high energy and large power density as a supercapacitor electrode material

RSC Advances ◽  
2016 ◽  
Vol 6 (56) ◽  
pp. 51332-51336 ◽  
Author(s):  
Yanli Tan ◽  
Qiuming Gao ◽  
Jiandong Xu ◽  
Zeyu Li
Keyword(s):  
Power Density ◽  
Porous Carbon ◽  
High Energy ◽  
Aqueous System ◽  
Porous Carbon Material ◽  
Koh Activation ◽  
Supercapacitor Electrode ◽  
Large Power ◽  
System P ◽  
Porous Coordination Polymer

1D nanorod-like porous carbon material synthesized by pyrolysis of porous coordination polymer following with KOH activation exhibits long cyclic stability and simultaneous high energy and large power density in the 6 M KOH aqueous system.

scholarly journals Photothermal Effect of Superparamagnetic Fe3O4 Nanoparticles Irradiated by Near-Infrared Laser

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Shawei Fu ◽  
Yuchun Man ◽  
Fuquan Jia
Keyword(s):  
Cancer Treatment ◽  
Power Density ◽  
Infrared Absorption ◽  
Fe3o4 Nanoparticles ◽  
Near Infrared ◽  
Infrared Laser ◽  
Photothermal Effect ◽  
Transduction Efficiency ◽  
Large Power ◽  
Fe3o4 Nps

Fe3O4 nanoparticles (NPs) have been widely used in biomedicine due to their unique magnetism, biocompatibility, and biodegradability. Magnetic hyperthermia of Fe3O4 NPs for cancer treatment has attracted more attention. However, it could interfere with magnetic field-sensitive devices of patients, such as pacemakers. Therefore, it is necessary to find a new method for clinical therapy. In this study, the superparamagnetic Fe3O4 NPs were fabricated. Visible-near-infrared absorption spectra indicated that the Fe3O4 NPs have near-infrared absorption. The influences of Fe3O4 NP concentrations, power density, and wavelength of near-infrared laser irradiation on the photothermal performance of Fe3O4 NPs were investigated. The results revealed that high concentrations, large power density, and short irradiation wavelength could improve the photothermal performance of Fe3O4 NPs. The temperature variation and the absorption intensity simultaneously determined the photothermal transduction efficiency of Fe3O4 NPs. The application of the photothermal performance of Fe3O4 NPs would provide a new opportunity for clinic cancer treatment.

A Cost‐Effective Mixed Matrix Polyethylene Porous Membrane for Long‐Cycle High Power Density Alkaline Zinc‐Based Flow Batteries

2019 ◽  
Vol 29 (29) ◽  
pp. 1901674 ◽  
Author(s):  
Nana Chang ◽  
Yanbin Yin ◽  
Meng Yue ◽  
Zhizhang Yuan ◽  
Huamin Zhang ◽  
...  
Keyword(s):  
Power Density ◽  
High Power ◽  
Cost Effective ◽  
Porous Membrane ◽  
High Power Density ◽  
Mixed Matrix ◽  
Long Cycle ◽  
Flow Batteries
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