scholarly journals Fibre-Reinforced Composite for Protection against Shark Bites

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5065
Author(s):  
Thomas Fiedler ◽  
Trent Verstegen
Keyword(s):  
The Novel ◽  
Test Rig ◽  
Complex Motion ◽  
Severe Injuries ◽  
Protective Material ◽  
Suitable Material ◽  
Shark Teeth ◽  
Reinforced Composite ◽  
Shark Attacks ◽  
Growing Population

The number of shark attacks resulting in fatalities and severe injuries has increased steadily over recent years. This is mainly attributed to a growing population participating in ocean sports such as swimming, diving, and surfing. To mitigate the severity of shark attacks, the current study presents a novel fibre-reinforced composite for bite protection. This material is intended for integration into neoprene wetsuits, e.g., in the form of protective pads. A suitable material must be able to withstand significant bite forces, which are concentrated within a small contact area at the tips of the shark teeth. At the same time, the material should not hinder the complex motion sequences of aquatic sports. To this end, a novel fibre-reinforced composite was created by integrating Kevlar fibres into an elastic matrix. Uni-axial testing using shark teeth replicas was conducted on a specially designed test rig to quantify the effectiveness of the novel protective material.

Load-Force-Adaptive Outlet Throttling: An Easily Commissionable Independent Metering Control Strategy

2016 ◽  
Author(s):  
Jan Lübbert ◽  
André Sitte ◽  
Benjamin Beck ◽  
Jürgen Weber
Keyword(s):  
Hydraulic System ◽  
Control Algorithm ◽  
Systematic Approach ◽  
Load Force ◽  
Chamber Pressure ◽  
The Novel ◽  
Test Rig ◽  
Mechanical Pressure ◽  
And Control ◽  
Inlet Chamber

This paper deals with a novel independent metering valve system which is intended to be used in medium sized mobile machines. The system uses a mechanical pressure compensator to enable a very simple SISO control algorithm which does not need any feedback parameters to be adjusted. The algorithm is capable of handling resistive and pulling loads at a certain desired velocity and inlet chamber pressure level. The paper gives a brief summary of the systematic approach to deriving the valves structure and compares different control approaches for the complete hydraulic system comprising several actuators. Special emphasis is given to the preferred solution, which is verified on a laboratory test rig consisting of reasonably priced mobile machine components. Furthermore a linear model of system and control structure is constructed to give detailed information regarding the dynamic characteristics of the controlled drive. The energetic benefits of the novel system architecture in comparison to a standard coupled metering flow sharing system are investigated by means of a levelling movement performed on the test rig and a simulated synthetic high power digging cycle.

scholarly journals Design of an Innovative Test Rig for Industrial Bearing Monitoring with Self-Balancing Layout

Machines ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 54
Author(s):  
Eugenio Brusa ◽  
Cristiana Delprete ◽  
Lorenzo Giorio ◽  
Luigi Gianpio Di Maggio ◽  
Vittorio Zanella
Keyword(s):  
Industrial Applications ◽  
The Novel ◽  
Axial Loads ◽  
Test Rig ◽  
System Failures ◽  
Novel Concept ◽  
Time Required ◽  
The Impact ◽  
Bearing Monitoring

The remote prognosis and diagnosis of bearings can prevent industrial system failures, but the availability of realistic experimental data, being as close as possible to those detected in industrial applications, is essential to validate the monitoring algorithms. In this paper, an innovative bearing test rig architecture is presented, based on the novel concept of “self-contained box”. The monitoring activity is applicable to a set of four middle-sized bearings simultaneously, while undergoing the independent application of radial and axial loads in order to simulate the behavior of the real industrial machinery. The impact of actions on the platform and supports is mitigated by the so-called “self-contained box” layout, leading to self-balancing of actions within the rotor system. Moreover, the high modularity of this innovative layout allows installing various sized bearings, just changing mechanical adapters. This leads to a reduction of cost as well as of system down-time required to change bearings. The test rig is equipped with suitable instrumentation to develop effective procedures and tools for in- and out-monitoring of the system. An initial characterization of the healthy system is presented.

A Long Look at Head Injuries

1989 ◽  
Vol 52 (3) ◽  
pp. 101-102 ◽  
Author(s):  
P S London
Keyword(s):  
Long Term Care ◽  
Head Injuries ◽  
Severe Injury ◽  
Early Care ◽  
Severe Injuries ◽  
Term Care ◽  
Early Stages ◽  
The Brain ◽  
Growing Population

Over the last 40 years, improved standards of early care have created a growing population of disabled survivors of severe injuries of the brain. Solutions for this growing problem exist but they can never be complete. There is understandable and justifiable concern about the deficiencies in the long-term care of the victims of severe injury of the brain, who are to some extent the price of success in the management of such injuries during the early stages and so keeping alive brains that cannot recover fully.

scholarly journals INVESTIGATION OF A NOVEL PRESSURE-ACTUATED BRUSH SEAL UNDER HOT STEAM CONDITIONS

2020 ◽  
Vol 4 ◽  
pp. 14-26
Author(s):  
Philip Reggentin ◽  
Jens Friedrichs ◽  
Johan Flegler ◽  
Ivan McBean
Keyword(s):  
Power Plants ◽  
The Novel ◽  
Basic Design ◽  
Test Rig ◽  
Brush Seal ◽  
Brush Seals ◽  
Increasing Demand ◽  
Improved Design ◽  
Flexible Operation ◽  
Novel Design

Due to the increasing demand towards flexible operation of conventional power plants also the seals of their turbines have to adapt to varying loads. Based on the basic design of a clamped brush seal, a novel seal with a pressure-actuated backplate is introduced which is capable of combining the advantages of low and high inclined brush seals while avoiding their undesired properties for flexible operation. During preliminary investigations on a test rig operated with compressed air and without rotation, the functionality of the improved design was demonstrated. It is shown that the leakage mass flow was lowered by up to 40% while undesired bristle oscillations were reduced by up to 90% at low pressure differences compared to conventional seal designs. After the adaption of the design for subsequent investigations under realistic conditions comparable to those in a steam turbine, further tests were conducted at TU Braunschweig´s hot steam test rig. Within these investigations the novel design showed improved properties regarding a high leakage performance and an advanced capability to avoid deterioration due to shaft excursions compared to brush seals with fixed backplate design.

Refinement of the Maxwell Formula for Fiber-Reinforced Composites

2019 ◽  
Vol 11 (01) ◽  
pp. 1950001
Author(s):  
Alexander Kalamkarov ◽  
Igor Andrianov ◽  
Galina Starushenko
Keyword(s):  
Thermal Conductivity ◽  
Physical Properties ◽  
Effective Properties ◽  
Principal Term ◽  
The Novel ◽  
Fiber Reinforced ◽  
Reinforced Composite ◽  
Coefficient Of Thermal Conductivity ◽  
Shape Perturbation ◽  
Limiting Values

The effective properties of the fiber-reinforced composite materials with fibers of square cross-section are investigated. The novel formula for the effective coefficient of thermal conductivity refining the classical Maxwell formula (MF) is derived. The methods of asymptotic homogenization, boundary shape perturbation and Schwarz alternating process are applied. It is shown that the principal term of the asymptotic expansion of the refined formula in powers of small size of inclusions coincides with the classical MF. The corrections to the MF are obtained for different values of geometrical and physical properties of the constituents of the composite material. The analytical and numerical analyses are carried out and illustrated graphically. In particular, the derived refined formula and the MF are compared for the limiting values of the geometric dimensions and physical properties of the composite. It is shown that the refined formula is applicable for the inclusions with any conductivity in the entire range of the geometric sizes of inclusions, including the limiting cases of inclusions with zero thermal conductivity and maximally large inclusions.

scholarly journals Refinement of the Maxwell formula for a composite reinforced by circular cross-section fibres. Part II: using Padé approximants

2020 ◽  
Vol 231 (12) ◽  
pp. 5145-5157
Author(s):  
Igor I. Andrianov ◽  
Jan Awrejcewicz ◽  
Galina A. Starushenko ◽  
Vladimir A. Gabrinets
Keyword(s):  
Composite Materials ◽  
Cross Section ◽  
Volume Fraction ◽  
Effective Properties ◽  
Circular Cross Section ◽  
The Novel ◽  
High Contrast ◽  
Asymptotic Results ◽  
Reinforced Composite ◽  
Coefficient Of Thermal Conductivity

Abstract The effective properties of the fiber-reinforced composite materials with fibers of circle cross section are investigated. The novel estimation for the effective coefficient of thermal conductivity refining the classical Maxwell formula is derived. The method of asymptotic homogenization is used. For an analytical solution of the periodically repeated cell problem the Schwarz alternating process (SAP) was employed. Convergence of this method was proved by S. Mikhlin, S. Sobolev, V. Mityushev. Unfortunately, the rate of the convergence is often slow, especially for nondilute high-contrast composite materials. For improving this drawback we used Padé approximations for various forms of SAP solutions with the following additive matching of obtained expressions. As a result, the solutions in our paper are obtained in a fairly simple and convenient form. They can be used even for a volume fraction of inclusion very near the physically possible maximum value as well as for high-contrast composite constituents. The results are confirmed by comparison with known numerical and asymptotic results.

Investigation of the power losses of the hybrid transmission DE-REX based on modeling and measurement

2019 ◽  
Vol 233 (14) ◽  
pp. 3646-3657
Author(s):  
Ye Shen ◽  
Andreas Viehmann ◽  
Stephan Rinderknecht
Keyword(s):  
Experimental Data ◽  
Electric Vehicles ◽  
Power Loss ◽  
The Novel ◽  
Power Losses ◽  
Test Rig ◽  
Hybrid Powertrain ◽  
Range Extender ◽  
Hybrid Powertrains ◽  
Hybrid Transmission

Electric and hybrid powertrains are developed to reduce the energy and fuel consumption of vehicles. Recently, multi-speed transmission systems were discussed for further reduction of the energy consumption of electric vehicles. Therefore, analyzing the power losses of such transmissions is of interest. In this paper, the novel powertrain concept DE-REX (Two-Drive-Transmission with Range-Extender) and the experimental investigation of its overall power losses is first introduced. A method is then developed to model and analyze the power losses of this hybrid transmission based on experimental data. After the validation of the method, the overall power loss model is eventually applied to estimate the power losses of the transmission at other driving modes, which were not measured on the test rig. The method is used to understand the characteristics of power losses inside the transmission in a hybrid powertrain and to optimize powertrain power losses in future.

Application of Recently Developed MCDM Methods for Materials Selection

2015 ◽  
Vol 809-810 ◽  
pp. 1468-1473
Author(s):  
Dušan Petković ◽  
Miloš Madić ◽  
Miroslav Radovanović ◽  
Predrag Janković
Keyword(s):  
Decision Making ◽  
Material Selection ◽  
Selection Process ◽  
Multi Criteria Decision Making ◽  
The Novel ◽  
Materials Selection ◽  
Suitable Material ◽  
Product Assessment ◽  
Designed Materials ◽  
Selection Of

It is well known fact that materials play an important role in engineering design. Nowadays over a hundred thousand available materials can be distinguished with constant tendency for increasing the novel designed materials. Therefore material selection process becomes a complex and time consuming task. Selection of the most suitable material for a given application can be regarded as a multi-criteria decision making (MCDM) problem with conflicting and diverse objectives. New MCDM methods have been developed, and existing methods improved, showing that research in the decision-making is important and still valuable. This paper describes the use of recently developed MCDM methods, i.e. Complex Proportional Assessment (COPRAS) and Weighted Aggregated Sum Product Assessment (WASPAS) for selecting the most suitable hard coating material.

Preparation and electrochromic properties of flexible transparent WO3/AgNWs decorated nanofiber composite film

2021 ◽  
Author(s):  
Byoung-Suhk Kim
Keyword(s):  
Silver Nanowires ◽  
Composite Films ◽  
The Novel ◽  
Smart Window ◽  
Nanofiber Composite ◽  
Transparent Films ◽  
Coloration Efficiency ◽  
Reinforced Composite ◽  
Experimental Protocols ◽  
Improved Performance

Abstract It is well-known that tungsten oxide (WO3) is extensively used for electrochromic (EC) devices due to their special properties such as high coloration/bleaching response time, good coloration efficiency and so on. The preparation of flexible EC devices is highly desirable for various applications. However, the fabrication of flexible EC devices with improved performance is still major task due to their limited experimental protocols. In this work, we have prepared thr highly flexible transparent films consisting of WO3 and silver nanowires coated on nanofiber-reinforced composite films (WO3/AgNWs-NCF). The novel flexible transparent WO3/AgNWs-NCF is used for the electrochromic (EC) applications. The as-fabricated EC device based on WO3/AgNWs-NCF demonstrated a good coloration efficiency (161.3 cm2/C), excellent stability (81.5 %), and rapid respone time for coloration (2.9 sec) and bleaching (3.2 sec). The fabricated transparent flexible EC device may be potentially useful to design an outstanding EC device for a smart window application.

State Space Modeling and Stable Dynamic Inversion for Trajectory Tracking on an Industrial Seat Test Rig

2002 ◽  
Vol 8 (7) ◽  
pp. 1033-1050 ◽  
Author(s):  
J. De Cuyper ◽  
M. Verhaegen
Keyword(s):  
State Space ◽  
Trajectory Tracking ◽  
State Space Model ◽  
State Space Models ◽  
Dynamic Inversion ◽  
The Novel ◽  
Test Rig ◽  
Software Packages ◽  
Novel Approach ◽  
Space Modeling

This paper introduces a novel approach for trajectory tracking on seat test rigs. Seat test rigs are used in the automotive industry to test prototypes of new seats with respect to their comfort and vibration characteristics. Classically, a digital Fourier transform (DFT) approach, based on a Frequency Response Function (FRF) model, is used in this domain and different software packages exist that are based on this approach. The novel approach proposes state space models to identify the test rig and uses the recently developed Stable Dynamic Inversion (SDI) to invert the obtained state space models. The approach is validated on an industrial seat test rig and it is shown that the new approach is a competitive alternative to the existing DFT based methods. A closed loop experiment is also performed; this shows that the feedback controller allows one to reduce the state space model order without loss of accuracy.

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