An experimental characterization of wrinkling generated during prepreg autoclave manufacturing using caul plates

2019 ◽  
Vol 53 (26-27) ◽  
pp. 3757-3773 ◽  
Author(s):  
Tobias A Weber ◽  
Markus Englhard ◽  
Jan-Christoph Arent ◽  
Joachim Hausmann
Keyword(s):  
Experimental Characterization ◽  
Part Geometry ◽  
Quality Issue ◽  
Out Of Plane ◽  
Set Up ◽  
Wrinkle Generation ◽  
The Given ◽  
Part Thickness ◽  
Insight Into

Out-of-plane ply wrinkling is a major quality issue for carbon fiber reinforced prepreg parts. Its triggers are numerous and not every influencing parameter is fully understood, yet. The research presented in this paper aims at providing a better insight into ply wrinkling generated during autoclave compaction using caul plates. A detailed description of the experimental set-up and the applied methodology is provided. Statistical analyses of varying influencing factors such as part thickness, geometry, tool–part interaction, and laminate lay-up are presented. This, in turn, generates a better understanding of their impact on fiber wrinkling risk and size. Part geometry and compaction deformation show the most significant influence on wrinkle size. However, for the given manufacturing concept, tool–part interaction also plays a significant role. It influences both the dimension and location of the wrinkles, as well as the existence and size of a critical flange length of the part. A noteworthy effect on wrinkle generation and size can also be observed when adding unidirectional plies to an otherwise fabric laminate.

scholarly journals Friction and Wear Performance of Various Polymer Coatings for Journal Bearings under Stop Start Sliding

Lubricants ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 1
Author(s):  
Florian Summer ◽  
Florian Grün ◽  
Emma R Ravenhill
Keyword(s):  
Friction And Wear ◽  
Combustion Engine ◽  
Polymer Coatings ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Wear Performance ◽  
Set Up ◽  
Many Core ◽  
The Given

Increasing environmental legislation and demands for improved fuel economy performance have resulted in the introduction of various measures to optimize the internal combustion engine. Many of these actions significantly change the operating conditions of the engines and bring with them new challenges that original engine manufacturers (OEMs) have to solve. One example is stop start technology, which changes the operation of many core parts of engines such as journal bearings. Hence, the current paper deals with this topic. In particular, different polymer coated bearings have been studied regarding their friction and wear performance under stop start sliding. Detailed material characterization of the materials was carried out using light microscopy and scanning electron microscopy. Furthermore, tribometric tests were conducted under controlled and similar conditions on a TE92 tribometer using a bearing segment test set up. The results show that the various polymer coated bearings tested provide enhanced friction and wear performance in comparison to other bearing types (e.g., lead-based electroplated) and that friction and wear performance differs also among them. In this regard, a higher amount of solid lubricant fillers and a dense filler structure appears to be beneficial under the given test conditions.

scholarly journals Experimental Investigation of an Electrical Model for Sodium–Nickel Chloride Batteries

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2652
Author(s):  
Roberto Di Rienzo ◽  
Gianluca Simonte ◽  
Ian Biagioni ◽  
Federico Baronti ◽  
Roberto Roncella ◽  
...  
Keyword(s):  
Nickel Chloride ◽  
Battery Management ◽  
Experimental Characterization ◽  
Identification Process ◽  
Battery Model ◽  
Battery Management Systems ◽  
Set Up ◽  
Battery Technology ◽  
Validation Tests

This work describes the experimental characterization of a commercial sodium–nickel chloride battery and the investigation on a state-of-the-art model that represents the battery behavior. This battery technology is considered very promising but it has not fully been exploited yet. Besides improvements on the technological side, accurate models of the battery should be found to allow the realization of Battery Management Systems with advanced functions. This achievement may extend the battery exploitation to its best. The paper describes the experimental set-up and the model parameter identification process, and discusses the identified parameters and the model validation tests. The comparison between model simulations and experiments shows that the model is rather accurate for low-current rates, but it loses accuracy and it is not able to reproduce with fidelity the battery behavior at low states of charge or at high current rates. Further research efforts and refinements of the model are necessary to make available a sodium–nickel chloride battery model accurate in any operating condition.

scholarly journals Experimental characterization of the out-of-plane performance of regular stone masonry walls, including test setups and axial load influence

2015 ◽  
Vol 13 (9) ◽  
pp. 2667-2692 ◽  
Author(s):  
Tiago Miguel Ferreira ◽  
Alexandre A. Costa ◽  
António Arêde ◽  
Ana Gomes ◽  
Aníbal Costa
Keyword(s):  
Axial Load ◽  
Stone Masonry ◽  
Masonry Walls ◽  
Experimental Characterization ◽  
Out Of Plane

Experimental characterization of the out-of-plane behaviour of masonry infill walls made of lightweight concrete blocks

2021 ◽  
Vol 244 ◽  
pp. 112755
Author(s):  
Marta Agante ◽  
André Furtado ◽  
Hugo Rodrigues ◽  
António Arêde ◽  
Paulo Fernandes ◽  
...  
Keyword(s):  
Lightweight Concrete ◽  
Experimental Characterization ◽  
Infill Walls ◽  
Masonry Infill ◽  
Masonry Infill Walls ◽  
Out Of Plane ◽  
Concrete Blocks

scholarly journals A prototype characterization of ExoFinger, a finger exoskeleton

2021 ◽  
Vol 18 (3) ◽  
pp. 172988142110248
Author(s):  
Marco Ceccarelli ◽  
Cuauhtemoc Morales-Cruz
Keyword(s):  
Power Consumption ◽  
Efficient Solution ◽  
Experimental Characterization ◽  
Operation Performance ◽  
Finger Temperature ◽  
Motion Range ◽  
Finger Motion ◽  
Large Motion ◽  
The Given

This article presents an experimental characterization of ExoFinger, a finger exoskeleton for finger motion assistance. The exoskeletal device is analyzed in experimental lab activities that have been conducted with different users to characterize the operation performance and to demonstrate the adaptability of the proposed device. The behavior of this device is characterized in detail using sensors to measure finger motion and power consumption. Sensor measures also demonstrate the given motion assistance performance in terms of an electrical finger response and finger temperature by resulting in an efficient solution with a large motion range of a finger in assistance of recovering finger motion.

Articulated MEMS Robot for Microfactory Applications

2009 ◽  
Author(s):  
Rakesh Murthy ◽  
Dan O. Popa
Keyword(s):  
Range Of Motion ◽  
Experimental Characterization ◽  
Micro Electro Mechanical Systems ◽  
End Effector ◽  
Nano Indentation ◽  
Experimental Identification ◽  
Work Volume ◽  
Out Of Plane ◽  
Flexure Joints

A MEMS (Micro Electro Mechanical Systems) based four degree of freedom articulated microrobot is presented as an example of next generation miniaturized top down manipulators. The robot occupies 6mm3 in total volume with room for further down scaling. The operating work volume is 50μm × 50μm × 75μm with a 2P2R (Prismatic Prismatic Revolute Revolute) kinematic configuration — X, Y, Pitch and Yaw. The presented microrobot design rises above commonly encountered performance tradeoff’s of previous MEMS positioners such as range of motion vs. exerted force and range of motion vs. precision. It is constructed using a combination of hybrid microassembly and high aspect ratio micromachining. Structurally, the first version of the microrobot consists of Silicon 2 1/2 D parts and a 30μm diameter Cu wire. The robot joints and attachment of the end effector are accomplished by microassembly using compliant snap-fasteners, monolithic flexure joints, and epoxy glue. Actuation is carried out by two banks of in-plane electrothermal actuators, one coupled through an out of plane compliant socket, and the other one coupled remotely using a 30 μm diameter Cu wire. In this paper we present the microrobot kinematic design, and experimental identification of the robot Jacobian. Preliminary experimental characterization of the microrobot shows that it is repeatable to less than 0.5 μm along XY axes and 0.015 degrees along Pitch and Yaw DOFs. Finally, the robot was configured to carry an AFM tip and we demonstrate nano indentation sequences on a Parylene substrate.

scholarly journals How Geometric Misalignments can affect the Accuracy of Measurements by a Novel Configuration of Self-Tracking LDV

ACTA IMEKO ◽  
2014 ◽  
Vol 3 (4) ◽  
pp. 26 ◽  
Author(s):  
Giuseppe Dinardo ◽  
Laura Fabbiano ◽  
Gaetano Vacca
Keyword(s):  
Single Point ◽  
Laser Doppler Vibrometer ◽  
The Self ◽  
Laser Doppler ◽  
Tracking Technique ◽  
Accuracy Of Measurements ◽  
Experimental Apparatus ◽  
Out Of Plane ◽  
Set Up

Aim of the paper is to evaluate the reliability of a novel configuration of a Laser Doppler Vibrometer (LDV) for the measurement of vibrations affecting rotating components of machines. In the paper an analysis of errors due to the possible static misalignments of the mirrors utilized in an experimental apparatus has been carried out. This instrument was set up for the estimation of the out of plane vibrations of moving (rotating) objects, in order to give a better characterization of the self-tracking technique employed with the use of a 1D single point LDV and its measurements. The accuracies of the measures are mostly linked to the interaction between environment and instrumentation.

Whipping instability characterization of an electrified visco-capillary jet

2011 ◽  
Vol 671 ◽  
pp. 226-253 ◽  
Author(s):  
GUILLAUME RIBOUX ◽  
ÁLVARO G. MARÍN ◽  
IGNACIO G. LOSCERTALES ◽  
ANTONIO BARRERO
Keyword(s):  
High Speed ◽  
Dielectric Liquid ◽  
Taylor Cone ◽  
The Other ◽  
Experimental Characterization ◽  
Dimensionless Numbers ◽  
Host Medium ◽  
Set Up ◽  
Axisymmetric Instability

The charged liquid micro-jet issued from a Taylor cone may develop a special type of non-axisymmetric instability, usually referred to in the literature as a whipping mode. This instability usually manifests itself as a series of fast and violent lashes of the charged jet, which makes its characterization in the laboratory difficult. Recently, we have found that this instability may also develop when the host medium surrounding the Taylor cone and the jet is a dielectric liquid instead of air. When the oscillations of the jet occur inside a dielectric liquid, their frequency and amplitude are much lower than those of the oscillations taking place in air. Taking advantage of this fact, we have performed a detailed experimental characterization of the whipping instability of a charged micro-jet within a dielectric liquid by recording the jet motion with a high-speed camera. Appropriate image processing yields the frequency and wavelength, among the other important characteristics, of the jet whipping as a function of the governing parameters of the experimental set-up (flow rate and applied electric field) and liquid properties. Alternatively, the results can be also written as a function of three dimensionless numbers: the capillary and electrical Bond numbers and the ratio between an electrical relaxation and residence time.

scholarly journals Experimental Characterization of the In-plane and Out-of-Plane Behaviour of Infill Masonry Walls

2015 ◽  
Vol 114 ◽  
pp. 862-869 ◽  
Author(s):  
André Furtado ◽  
Hugo Rodrigues ◽  
António Arêde ◽  
Humberto Varum
Keyword(s):  
Masonry Walls ◽  
Experimental Characterization ◽  
Out Of Plane ◽  
Infill Masonry
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