Investigation of the influence of recyclate content on Poisson number of composites

Abstract Composite materials are used in many industries. Their mechanical and physical properties as well as their low weight make them suitable for use in many constructions. Their wide application generates a problem with their disposal. Therefore, it is necessary to design new materials based on waste from polyester–glass laminates in order to introduce a closed circuit in the composite production process. The article presents research aimed at determining solid material composites with polyester–glass recyclate, in order to use these materials for modeling the structure. The aim of this study was to determine the effect of the addition of recyclate to the polyester–glass composite on the deformation and the value of the Poisson number of the material. During the study, samples from composites with the addition of polyester–glass recyclate were used. Samples made in accordance with the standard for plastics PN-EN ISO 527-4_2000P were subjected to static tensile test on a universal testing machine, with variable load parameters. During the test, the longitudinal and transverse elongations of the samples were measured using a strain gauge measuring system. On the basis of the measurements, the values of Poisson numbers were determined, which allowed for a preliminary assessment of the impact of the recyclate content in the composite on its deformability.

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IMPACT TENSILE PROPERTIES OF YAG LASER WELDED BUTT JOINTS MADE BY DIFFERENT STEEL SHEETS FOR VEHICLES

International Journal of Modern Physics B ◽

10.1142/s0217979208047304 ◽

2008 ◽

Vol 22 (09n11) ◽

pp. 1712-1717

Author(s):

Y. TAKAHASHI ◽

M. DAIMARUYA ◽

H. KOBAYASHI ◽

H. TSUDA ◽

H. FUJIKI

Keyword(s):

Tensile Properties ◽

Welded Joints ◽

Testing Machine ◽

High Strength ◽

Tensile Tests ◽

Butt Joints ◽

Yag Laser ◽

Steel Sheets ◽

Static Tensile ◽

The Impact

The tensile properties of YAG laser welded butt joints using different high strength steel sheets with a tensile strength of 270 MPa, 590 MPa and 980 MPa (denoted HR270, HR590 and HR980, respectively) were investigated at static and dynamic rates, together with the three kinds of laser welded joints made by the same steel sheets. The impact tensile tests were performed by using the vertical type of split Hopkinson tension bar apparatus, while the static tensile tests were carried out using a universal testing machine INSTRON5586. The impact tensile strengths were significantly increased in comparison with the static ones due to the effect of strain rate, which might be the contribution of the part of HR270 base metal. And in both of static and impact tests, the fracture strains of HR270-HR590 joint, HR270-HR980 joint and HR590-HR980 joint were about one half of the fracture strains observed in the same steel welded joints of HR270-HR270, HR270-HR270 and HR590-HR590, respectively.

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Evaluation of wettability characteristics and adhesion of resin composite to photo-polymerized pulp-capping materials with and without bioactive glass

Brazilian Dental Science ◽

10.14295/bds.2019.v22i3.1703 ◽

2019 ◽

Vol 22 (3) ◽

pp. 335-343

Author(s):

Fatih Tulumbaci ◽

Emre Korkut ◽

Hazal Ozer ◽

Mutlu Özcan

Keyword(s):

Contact Angle ◽

Bond Strength ◽

Shear Bond Strength ◽

Sessile Drop ◽

Resin Composite ◽

Testing Machine ◽

Adhesive System ◽

Significant Difference ◽

Mechanical And Physical Properties ◽

Made In

Objective: The purpose of this study was to evaluate mechanical and physical properties of three different light-curable resin-based materials (TheraCal LC, Biner LC, and CalciPlus LC) with or without BAG. Material and Methods: 15 cylindrically shaped specimens (n=5) were prepared for contact angle test. The test values (Θ) were determined with the sessile drop method using three test liquids. 30 acrylic cylindrical blocks were prepared, and holes of (6mmx1mm) were made in the center of the cylinders for shear bond strength test. An adhesive system and a restorative composite material were applied via cylindrically shaped plastic tubes of (2mmx2mm) at the center of the light-curable resin-based material surfaces. The specimens were mounted in a universal testing machine. A crosshead speed of 1 mm/min was applied to each specimen using a knife-edge blade. Results: The highest (74.77°±13.56) and the lowest (35.35°±12.89) contact angle values were recorded for the MB Biner LC group and the CalciPlus LC, respectively. Statistically significant differences observed in contact angle values between the test groups (p<0.05). The surface free energy of Biner LC (γS 36.22) was lower than that of TheraCal LC (γS 44.70) and CalciPlus LC (γS 46.20) (p<0.05). There was no significant difference in shear bond strength values between TheraCal LC and CalciPlus LC (p>0.05). Conclusions: Hydrophilic property of Theracal LC and Calciplus LC resulted in better bonding strength in these materials. The BAG used in Calciplus LC did not adversely affect mechanical and surface properties of the material.

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DESIGN OF FORCE MEASURING SYSTEM ON MAIN LANDING GEAR WEIGHT DROP TESTING MACHINE FOR THE APPLICATION OF LSU SERIES

Jurnal Teknologi Dirgantara ◽

10.30536/j.jtd.2020.v18.a3377 ◽

2020 ◽

Vol 18 (2) ◽

pp. 159

Author(s):

Yusuf Giri Wijaya ◽

Abian Nurrohmad

Keyword(s):

Data Acquisition ◽

Reaction Force ◽

Testing Machine ◽

Data Acquisition System ◽

Landing Gear ◽

Load Cell ◽

Acquisition System ◽

Measuring System ◽

Weight Drop ◽

The Impact

In this research, the design of the force measuring system on main landing gear weight drop test for the LSU series that developed by LAPAN was carried out. The principle of this machine is to apply the load according to the weight of the aircraft on the main landing gear and drop it at a certain height assisted by the guiding rail. At the bottom of this machine there is a impact platform where each angle is mounted with a load cell that functions to measure the reaction force due to the impact of the main landing gear. In addition, there is a data acquisition system whose function is to process the output signal from load cell and display measurement data. The data acquisition system used consists of DAQ measurement hardware made by national instruments and LabVIEW software installed on a PC. The design of this testing tools aims to carry out a dynamic impact test on the main landing gear structure of the UAV. In this study, static calibration has also been successfully performed on the impact platform and shows consistent results for various test masses.

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Study of the characteristics of a sliding bearing under dynamic loading

MATEC Web of Conferences ◽

10.1051/matecconf/201929800039 ◽

2019 ◽

Vol 298 ◽

pp. 00039

Author(s):

Andrei Gorin ◽

Anton Sytin ◽

Alexey Rodichev

Keyword(s):

Control Systems ◽

Frequency Converter ◽

Visual Programming ◽

Measuring System ◽

Programming Environment ◽

Wide Range ◽

Information Measuring System ◽

The Impact ◽

Experimental Bench ◽

Made In

The article discusses the prerequisites and the process of creating an experimental bench for the study of external electromagnetic effects on rotor-bearing units in the work process. The control systems of the experimental setup and the electromagnetic device are presented, the latter is made in the form of 4 paired orthogonally located electromagnets. The percussion device can operate in a programmable mode. Flexible variation in speed and magnitude of the impact (according to a predetermined law of change) allows you to cover a wide range of possible external influences on the rotor unit. The tool for the automatic control of installation modules, as well as the collection and processing of experimental data, is software developed in the LabView visual programming environment. The drivers for matching the frequency converter and the controller, as well as all the software for the operation of the information-measuring system, the experiment and data processing, were written in the graphic programming language.

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Material Properties of HY 80 Steel after 55 Years of Operation for FEM Applications

Materials ◽

10.3390/ma14154213 ◽

2021 ◽

Vol 14 (15) ◽

pp. 4213

Author(s):

Szturomski Bogdan ◽

Kiciński Radosław

Keyword(s):

Material Properties ◽

Testing Machine ◽

Tensile Tests ◽

Pressure Waves ◽

The Finite Element Method ◽

Static Tensile ◽

The Republic ◽

Post War ◽

The Impact ◽

Dynamic Tensile Tests

The paper presents the results of testing the properties of HY 80 steel from the hull of a Kobben class 207 submarine after 60 years of operation in extreme sea conditions. Steels from the HY family in the post-war period were used to build American and German submarines. For the obtained fragment of steel from the hull of the Polish submarine ORP Jastrząb (ORP-Boat of the Republic of Poland), static tensile tests were performed on an MTS testing machine. Dynamic tensile tests were carried out on a rotary hammer for the strain rate in the range of 500–2000 s−1. Results: Based on the obtained results, the Johnson–Cook model and the failure parameters of HY 80 steel in terms of the finite element method (FEM) were developed. Conclusion: This model can be used to simulate fast-changing processes such as resistance of structures to collisions, shelling, and the impact of pressure waves caused by explosions in water and air related to submarines.

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Instrumental records received in 11 storey steel frame building during a remote earthquake

E3S Web of Conferences ◽

10.1051/e3sconf/202125809078 ◽

2021 ◽

Vol 258 ◽

pp. 09078

Author(s):

Vladimir Lapin ◽

Nurakhmet Makish ◽

Kamadiyar Kassenov ◽

Zhassulan Omarov ◽

Dauren Kassenov

Keyword(s):

Seismic Station ◽

Steel Frame ◽

Measuring System ◽

Spectral Curves ◽

Frame Building ◽

Digital Instrumentation ◽

Instrumental Records ◽

The Impact ◽

The City ◽

Made In

On August 9, 2017, a strong earthquake with a magnitude Mw = 6.3 occurred in the Xinjiang Uygur Autonomous Region of China. For the first time in the last 10 years, representative instrumental data were obtained at the seismic station No. 11 (“Prospect Abay”) in the city of Almaty, equipped with a digital instrumentation and measuring system. The building is eleven-story and is made in a steel frame. In the city of Almaty, there is a significant number of residential and public buildings made in a steel frame. Using the AT 1105 sensors and the RSM-8 recorder, high-quality instrumental records of accelerations in the basement and on the roof of the building were obtained, as well as the β spectral curves. The frequency composition of the impact at the basement level has been determined. The prevailing period of fluctuation at the basement level is 0.3 sec, and at the roof level is close to 1.3 sec. It was found that during a remote earthquake, resonant vibrations of the building took place. The results of the work can be used in the design of buildings with a steel frame in the city of Almaty.

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Metal Contamination of Stream Waters under the Impact of Tanneries

Pesquisas em Geociências ◽

10.22456/1807-9806.19514 ◽

2006 ◽

Vol 33 (2) ◽

pp. 55 ◽

Cited By ~ 1

Author(s):

MARIA LUCIA KOLOWSKI RODRIGUES ◽

MILTON LUIZ LAQUINTINIE FORMOSO

Keyword(s):

Water Quality ◽

Water Discharge ◽

Solid Material ◽

Total Variance ◽

Oxygen Conductivity ◽

Contamination Degree ◽

Iron Aluminum ◽

Relevant Variables ◽

Stream Waters ◽

The Impact

This study evaluated the contamination of water samples from Cadeia and Feitoria rivers (Rio Grande do Sul State, Brazil), affected by tannery activities. From July 1999 to April 2000, four sampling campaigns were performed at ten sites in order to evaluate selected metals and ancillary physicochemical variables. Sample preservation and analyses followed recommendations of the Standard Methods. Factor analysis was used to obtain statistical indexes representing the contamination degree of waters evaluated. The information was summarized in two principal components. The first, which accounted for 50% of the total variance, was associated to a tannery contribution and generated a contamination index. Total, Suspended and Dissolved Solids, Dissolved Oxygen, Conductivity, Chromium, Manganese, Copper, Nickel, Sodium, Calcium, Potassium, and Magnesium were the well-correlated variables with this first component. The water quality decreased from headwaters up to mouth along both streams, but the most contaminated sites were located at the lower reach of Feitoria river (Ivoti and Lindolfo Collor cities), where tanneries are concentrated. After the entrainment of Feitoria waters (São Sebastião do Caí municipality), Cadeia river also presented an increased contamination degree. The application of statistical randomization tests highlighted these same sites as significantly distinct from the others. Water contamination also showed association to flow variations, and a poorer water quality was observed during the dry period (January). The second component, in which Iron, Aluminum, and Suspended Solids were the relevant variables, was loaded with 15% of the total variance. It was linked to natural events, since higher factor scores in this component were obtained during a period of increased water discharge (October), which caused resuspension and entrainment of solid material to the rivers bed. As a final result of the study, sampling stations were classified according to the contamination degree, and graphically represented on a basin map, which synthesized the environmental diagnosis.

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Evaluation of the Impact of Organic Fillers on Selected Properties of Organosilicon Polymer

Polymers ◽

10.3390/polym13071103 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1103

Author(s):

Sara Sarraj ◽

Małgorzata Szymiczek ◽

Tomasz Machoczek ◽

Maciej Mrówka

Keyword(s):

Tensile Strength ◽

Natural Fiber ◽

Accelerated Aging ◽

Strength Properties ◽

Visual Observation ◽

Walnut Shell ◽

Pistachio Shell ◽

Thermoplastic Matrix ◽

Static Tensile ◽

The Impact

Eco-friendly composites are proposed to substitute commonly available polymers. Currently, wood–plastic composites and natural fiber-reinforced composites are gaining growing recognition in the industry, being mostly on the thermoplastic matrix. However, little data are available about the possibility of producing biocomposites on a silicone matrix. This study focused on assessing selected organic fillers’ impact (ground coffee waste (GCW), walnut shell (WS), brewers’ spent grains (BSG), pistachio shell (PS), and chestnut (CH)) on the physicochemical and mechanical properties of silicone-based materials. Density, hardness, rebound resilience, and static tensile strength of the obtained composites were tested, as well as the effect of accelerated aging under artificial seawater conditions. The results revealed changes in the material’s properties (minimal density changes, hardness variation, overall decreasing resilience, and decreased tensile strength properties). The aging test revealed certain bioactivities of the obtained composites. The degree of material degradation was assessed on the basis of the strength characteristics and visual observation. The investigation carried out indicated the impact of the filler’s type, chemical composition, and grain size on the obtained materials’ properties and shed light on the possibility of acquiring ecological silicone-based materials.

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The Performance of CR180IF and DP600 Laser Welded Steel Sheets under Different Strain Rates

Materials ◽

10.3390/ma14061553 ◽

2021 ◽

Vol 14 (6) ◽

pp. 1553

Author(s):

Mária Mihaliková ◽

Kristína Zgodavová ◽

Peter Bober ◽

Anna Špegárová

Keyword(s):

Sheet Steel ◽

Testing Machine ◽

Dynamic Test ◽

Tensile Tests ◽

Joint Surface ◽

Strain Rates ◽

Interstitial Free ◽

Welded Steel ◽

Steel Sheets ◽

Static Tensile

The presented research background is a car body manufacturer’s request to test the car body’s components welded from dissimilar steel sheets. In view of the vehicle crew’s protection, it is necessary to study the static and dynamic behavior of welded steels. Therefore, the influence of laser welding on the mechanical and dynamical properties, microstructure, microhardness, and welded joint surface roughness of interstitial free CR180IF and dual-phase DP600 steels were investigated. Static tensile tests were carried out by using testing machine Zwick 1387, and dynamic test used rotary hammer machine RSO. Sheet steel was tested at different strain rates ranging from 10−3 to 103 s−1. The laser welds’ microstructure and microhardness were evaluated in the base metal, heat-affected zone, and fusion zone. The comprehensive analysis also included chemical analysis, fracture surface analysis, and roughness measurement. The research results showed that the strain rate had an influence on the mechanical properties of base materials and welded joints. The dynamic loading increases the yield stress more than the ultimate tensile strength for the monitored steels, while the most significant increase was recorded for the welded material.

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Handshake antimicrobial stewardship as a model to recognize and prevent diagnostic errors

Diagnosis ◽

10.1515/dx-2020-0032 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Justin B. Searns ◽

Manon C. Williams ◽

Christine E. MacBrayne ◽

Ann L. Wirtz ◽

Jan E. Leonard ◽

...

Keyword(s):

Antimicrobial Stewardship ◽

Interrater Reliability ◽

Diagnostic Errors ◽

Diagnostic Error ◽

Primary Treatment ◽

Treatment Team ◽

Children's Hospital ◽

Children’S Hospital ◽

The Impact ◽

Made In

AbstractObjectivesFew studies describe the impact of antimicrobial stewardship programs (ASPs) on recognizing and preventing diagnostic errors. Handshake stewardship (HS-ASP) is a novel ASP model that prospectively reviews hospital-wide antimicrobial usage with recommendations made in person to treatment teams. The purpose of this study was to determine if HS-ASP could identify and intervene on potential diagnostic errors for children hospitalized at a quaternary care children’s hospital.MethodsPreviously self-identified “Great Catch” (GC) interventions by the Children’s Hospital Colorado HS-ASP team from 10/2014 through 5/2018 were retrospectively reviewed. Each GC was categorized based on the types of recommendations from HS-ASP, including if any diagnostic recommendations were made to the treatment team. Each GC was independently scored using the “Safer Dx Instrument” to determine presence of diagnostic error based on a previously determined cut-off score of ≤1.50. Interrater reliability for the instrument was measured using a randomized subset of one third of GCs.ResultsDuring the study period, there were 162 GC interventions. Of these, 65 (40%) included diagnostic recommendations by HS-ASP and 19 (12%) had a Safer Dx Score of ≤1.50, (Κ=0.44; moderate agreement). Of those GCs associated with diagnostic errors, the HS-ASP team made a diagnostic recommendation to the primary treatment team 95% of the time.ConclusionsHandshake stewardship has the potential to identify and intervene on diagnostic errors for hospitalized children.

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