scholarly journals Numerical description of the viscoelastic properties of low- and high-filled elastomeric nanocomposites

2021 ◽  
pp. 19-24
Author(s):  
V. D. Kislitsyn ◽  
◽  
K. A. Mokhireva ◽  
◽  
Keyword(s):  
Stress Tensor ◽  
Viscoelastic Properties ◽  
High Accuracy ◽  
Deformation Curve ◽  
Viscoelastic Response ◽  
Equilibrium Curve ◽  
Constant Rate ◽  
Elastomeric Materials ◽  
Loading And Unloading ◽  
Unloading Time

In this work, an analytical solution is found for the change in the dissipative (inelastic) part of the stress tensor at a constant rate of uniaxial loading of the material within the framework of a new thermodynamic model of the behavior of viscoelastic materials. At the same time, a fairly accurate coincidence of the theoretical curve constructed on the basis of the obtained solution with the experimental results was demonstrated. For this, uniaxial tests with nested loading cycles were carried out for samples of low- and high-filled elastomeric nanocomposites with various fillers. At each section of loading and unloading, time holdings were set, which made it possible to neglect the temporal processes taking place in the material, this makes it possible to experimentally find the equilibrium deformation curve. The resulting equilibrium curve can be described using the elastic potential. Having determined the equilibrium (elastic) and finding the dissipative (inelastic) parts of the stress tensor, the viscoelastic response of the considered elastomeric materials was described with high accuracy.

Changes in Elastic and Viscoelastic Properties of Poly(Methyl methacrylate) by Physical Aging

2011 ◽  
Vol 314-316 ◽  
pp. 914-917
Author(s):  
Wen Bo Luo ◽  
Chu Hong Wang ◽  
Xiu Liu ◽  
Qiang Shen
Keyword(s):  
Aging Time ◽  
Viscoelastic Properties ◽  
Physical Aging ◽  
Creep Compliance ◽  
Aging Effect ◽  
Glassy Polymers ◽  
Time Range ◽  
Asymptotic Values ◽  
Constant Rate ◽  
Linear Manner

The influence of physical aging on mechanical properties of glassy polymers was investigated in this paper. After annealing above Tg to release the previous thermal and stress history, the polymethyl methacrylate (PMMA) samples were quenched to 27°C, aged for various times (ta), and were then stretched at the same temperature by two ways: (1) step stresses with four different magnitudes varying from 15MPa to 30MPa; (2) constant rate stretch up to fracture. The physical aging effect was monitored by measuring the initial instantaneous elastic modulus (E) and the fracture strength (σf) from the stress-strain curves as a function of ta up to 1368h. It is shown that both E and σf of the material increase with aging time and approach to their asymptotic values, which satisfy the KWW rule, while the isochronous creep compliance decreases with log ta in a linear manner within the aging time range considered in this paper.

scholarly journals ANALISIS EFEKTIVITAS PENETAPAN JALUR TERKAIT DENGAN DWELLING TIME DI KANTOR PELAYANAN UTAMA BEA DAN CUKAI TIPE A TANJUNG PRIOK

2019 ◽  
Vol 1 (1) ◽  
pp. 57-69
Author(s):  
Sunarmin Sunarmin ◽  
Noviandari Sari Utami ◽  
Wiwin Eka Yulianita
Keyword(s):  
Data Collection ◽  
Dwelling Time ◽  
Descriptive Research ◽  
Directorate General ◽  
Qualitative Descriptive ◽  
Loading And Unloading ◽  
Unloading Time

Path determination is one of the customs procedures regulated in Law No. 17 of 2006 on customs. Considering the Directorate General of Customs and Excise, especially Tanjung Priok Customs and Excise KPU is faced with two functions, namely service and supervision, the strategic step taken to answer the problems of both functions is by determining the path. This study aims to discuss the determination of paths associated with dwelling time. The main problem in this research is the extent of the effectiveness of the application of the determination of the path and its relation to the dwelling time which is the loading and unloading time of the container carried from the vessel to the container out of the port. This research is a qualitative descriptive research with data collection techniques in the form of interviews and data secondary. From the results of interviews and data processed by the authors then concluded that with the establishment of a system of determining the path at the Tanjung Priok Customs and Excise KPU has been quite effective in reducing the dwelling time in the port of Tanjung Priok.

Influence of Decorin and Biglycan on Tensile Viscoelastic Properties in Knockout Mice

2011 ◽  
Author(s):  
LeAnn M. Dourte ◽  
Lydia Pathmanathan ◽  
Renato V. Iozzo ◽  
Louis J. Soslowsky
Keyword(s):  
Knockout Mice ◽  
Viscoelastic Properties ◽  
Linear Response ◽  
Mechanical Response ◽  
Tissue Response ◽  
Treatment Modalities ◽  
Viscoelastic Response ◽  
Composition And Structure ◽  
Biocomposite Material

Tendons have a complex, viscoelastic mechanical behavior that depends on their composition and structure. Understanding these structure-function relationships may help elucidate important differences in the varying functional behaviors of specific tendons as well as guide targeted treatment modalities and tissue engineered constructs. The tendon extracellular matrix (ECM) can be described as a biocomposite material consisting of collagen fibers surrounded by an extrafibrillar matrix. Many studies have focused on the role of the fibers on the tensile properties of tendon; however, fibers alone do not completely explain the viscoelastic and non-linear response of tendon. The interactions of small leucine-rich proteoglycans (SLRPs) with other ECM molecules, such as collagen fibrils, as well as their association with water suggest that SLRPs may play a role in tendon viscoelasticity. Some studies have assessed the role of SLRPs or glycosaminoglycans in the mechanical response of tendon, but few have explored their role in more sophisticated viscoelastic properties. Therefore, the objective of this study was to evaluate the viscoelastic response of the patellar tendon in two different SLRP knockout mice compared to wildtype. We hypothesized that the absence of SLRPs would lead to a stiffer dynamic tissue response compared to wildtype.

scholarly journals Relationship between Methods of Loading and Unloading, Carcass Bruising, and Animal Welfare in the Transportation of Extensively Reared Beef Cattle

Animals ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 119 ◽  
Author(s):  
Stella Huertas ◽  
Rick Kempener ◽  
Frank van Eerdenburg
Keyword(s):  
Beef Cattle ◽  
Animal Welfare ◽  
Truck Drivers ◽  
Substantial Part ◽  
Beef Production ◽  
Significant Difference ◽  
Loading And Unloading ◽  
Grade 3 ◽  
Unloading Time

In Uruguay, extensive, welfare-friendly beef production is a substantial part of the economy and culture. Transport of beef cattle to slaughterhouse compromises animal welfare. The objective of this study was to assess transport conditions related to carcass bruising. A total of 242 trucks with 8132 animals were assessed on loading, transport, unloading conditions, and carcass bruising. Average loading time was 26 min and 21 s and the perception of the truck drivers was correlated with the time took for loading and the use of devices. In 39.3% of the loadings only a flag was used. The average unloading time was 5 min and 54 s with a significant difference in time for the use of devices; only flag 3 min 51 s, cattle prod 6 min 43 s and sticks 8 min 09 s. Of the carcasses observed, 772 (9.5%) had no bruises, 873 (10.7%) had one bruise, 1312 (16.1%) two, 1231 (15.1%) three and 3944 (48.5%) had four or more bruises. Prevalence of bruises were highest on the Tuber-coxea (hip) (29.3%) following forequarter (22.4%), Tuber-ischiadicum (rear) (17.3%), ribs/flank (14.1%), rump/round (10.1%) and loin (6.8%). Bruises were 68.7% grade 1 and 31.3 % grade 2; there were no grade 3, the deepest ones, observed. It appeared that animal welfare training of truck drivers worked out well and the use of flags increased compared to a previous study in 2008.

Characterisation and Approval of FKM Polymers and Compounds with RPA – an Initial Experience Report

2018 ◽  
Vol 45 (4) ◽  
pp. 183-190
Author(s):  
J. Guntrum ◽  
G. Dinu-Biringer ◽  
T. Weber ◽  
J. Klein
Keyword(s):  
Viscoelastic Properties ◽  
High Strain ◽  
High Accuracy ◽  
Shop Floor ◽  
Suitable Alternative ◽  
Test Conditions ◽  
Rubber Compounds ◽  
Normal Test ◽  
Mooney Viscosity ◽  
Accuracy And Repeatability

For decades, measurement of the Mooney viscosity has been used for testing the viscosity of raw polymers and mixed stocks. The Mooney viscometer is commonly used on the shop floor alongside the rheometer. The relevance of the Mooney test for the processing of rubber compounds is limited and the use of a rubber process analyser (RPA) is a suitable alternative. The instrument is robust, easy to handle and therefore perfectly suitable for day-to-day use on the shop floor. High accuracy and repeatability of the measurement are further advantages. This article describes initial experiences with testing FKM raw polymers and compounds based on frequency and strain sweeps. Tests under high strain in particular demonstrate significant differences between polymers, which are not seen under normal test conditions (small amplitudes). In this way, rubber compounders and processors receive considerably more information about the viscoelastic properties of the raw polymers used and the compounds produced from them.

scholarly journals ANALISIS EFEKTIVITAS PENETAPAN JALUR TERKAIT DENGAN DWELLING TIME DI KANTOR PELAYANAN UTAMA BEA DAN CUKAI TIPE A TANJUNG PRIOK

2019 ◽  
Vol 1 (1) ◽  
pp. 57-69
Author(s):  
Sunarmin Sunarmin ◽  
Noviandari Sari Utami ◽  
Wiwin Eka Yulianita
Keyword(s):  
Data Collection ◽  
Dwelling Time ◽  
Descriptive Research ◽  
Directorate General ◽  
Qualitative Descriptive ◽  
Loading And Unloading ◽  
Unloading Time

Path determination is one of the customs procedures regulated in Law No. 17 of 2006 on customs. Considering the Directorate General of Customs and Excise, especially Tanjung Priok Customs and Excise KPU is faced with two functions, namely service and supervision, the strategic step taken to answer the problems of both functions is by determining the path. This study aims to discuss the determination of paths associated with dwelling time. The main problem in this research is the extent of the effectiveness of the application of the determination of the path and its relation to the dwelling time which is the loading and unloading time of the container carried from the vessel to the container out of the port. This research is a qualitative descriptive research with data collection techniques in the form of interviews and data secondary. From the results of interviews and data processed by the authors then concluded that with the establishment of a system of determining the path at the Tanjung Priok Customs and Excise KPU has been quite effective in reducing the dwelling time in the port of Tanjung Priok.

scholarly journals Analysis of Model Loading and Unloading Time of Ships at Boom Baru Port, Palembang, Indonesia

2017 ◽  
Vol 138 ◽  
pp. 07012
Author(s):  
Erika Buchari ◽  
Dinar Dwi Anugerah Putranto ◽  
Aulia Rahman
Keyword(s):  
Loading And Unloading ◽  
Unloading Time
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