scholarly journals Experimental viscoelastic properties evaluation, under impact loads and large strain conditions, of coated & uncoated rubber from end-of-life tires

2022 ◽  
pp. 107468
Author(s):  
J. González-Vega ◽  
G. Castillo-López ◽  
J.M. Galindo-Moreno ◽  
S. Guerrero-Porras ◽  
F. García-Sánchez
Keyword(s):  
End Of Life ◽  
Viscoelastic Properties ◽  
Large Strain ◽  
Impact Loads

scholarly journals Rheological measurements of the viscoelastic properties of snow

2001 ◽  
Vol 32 ◽  
pp. 44-50 ◽  
Author(s):  
Christian Camponovo ◽  
Jürg Schweizer
Keyword(s):  
Viscoelastic Properties ◽  
Deformation Process ◽  
Large Strain ◽  
Measuring Method ◽  
Shear Loading ◽  
Small Samples ◽  
Rheological Parameters ◽  
Viscoelastic Deformation ◽  
Dependent Part ◽  
Applied Torque

AbstractIn order to determine the viscoelastic properties of snow, torsional shear measurements were performed in a cold laboratory with a stress-controlled rheometer. Small samples (60 mm in diameter and about 7 mm thick of natural snow collected from the nearby study plot were loaded in simple shear with monotonically increasing stress (stress ramp) and with sinusoidally varying stress (oscillation). The dynamic measuring method allows the deformation process to be separated into a time-independent part (elastic) and a time-dependent part (viscous). The applied torque is sufficiently small to prevent destructive deformation, generally permitting the true viscoelastic properties of a sample to be obtained over a large range of frequency and temperature. The limit strain for linear viscoelastic deformation was found to be very small (0.5−5 × 10−4). Experiments performed beyond the linear range imply important textural changes (damage, breaking of bonds). The large strain reached during stress-ramp experiments showed that the ongoing damage process must be balanced by a healing (sintering) process. The usefulness of a rheometer was proven. It is a precise method for measuring with high reproducibility the rheological parameters of snow, and data gained with it improve our understanding of the deformation process under shear loading.

Comparison of Bitumen’s Large Strain Viscoelastic Properties in Cables and Umbilicals to Small Strain Rheometer Measurements

2016 ◽  
Author(s):  
Bjørn Konradsen
Keyword(s):  
Shear Stress ◽  
Viscoelastic Material ◽  
Viscoelastic Properties ◽  
Large Strain ◽  
Steel Wire ◽  
Small Strain ◽  
Strain Comparison

When a steel wire armored cable or umbilical is bent, the armor wires will move relative to the underneath layer if the wires are free to move. If this movement is restricted by friction or stiff bitumen, the bending will result in shear stress in the armor wires. In the case of bitumen, the bitumen will behave as a viscoelastic material dependent on temperature, frequency, and strain. Comparison of measurements of bitumen with small and large strain shows that the viscoelastic properties of bitumen are highly affected by the size of the strain. Therefore, the small strain rheometer measurements are not suitable for describing the viscoelastic properties of bitumen in the case of repeated bending of the cable or umbilical to a certain curvature.

VISCOELASTIC PROPERTIES OF CFRP SUBJECTED TO IMPACT LOADS

1992 ◽  
pp. 351-356
Author(s):  
Y. SOGABE ◽  
M. TSUZUKI ◽  
T. SENDA ◽  
K. KISHIDA
Keyword(s):  
Viscoelastic Properties ◽  
Impact Loads

Temperature Dependence of Viscoelastic Properties of CFRP Subjected to Impact Loads.

1991 ◽  
Vol 40 (455) ◽  
pp. 1111-1117
Author(s):  
Yuji SOGABE ◽  
Masayuki TSUZUKI ◽  
Katsunori SAKAI ◽  
Toyomitsu SENDA ◽  
Keizo KISHIDA
Keyword(s):  
Temperature Dependence ◽  
Viscoelastic Properties ◽  
Impact Loads

Viscoelastic Large Strain Model of Bitumen Used for Corrosion Protection in Subsea Cables and Umbilicals

2015 ◽  
Author(s):  
Magnus Komperød ◽  
Bjørn Konradsen ◽  
Roger Slora
Keyword(s):  
Strain Amplitude ◽  
Viscoelastic Properties ◽  
Amplitude Ratio ◽  
Large Strain ◽  
Real Life ◽  
Analytical Models ◽  
Large Strains ◽  
New Instrument ◽  
Strain Model ◽  
Strain Frequency

Bitumen is used as anticorrosion material to protect armor wires in subsea cables and umbilicals. Establishing bitumen’s viscoelastic properties is essential for developing analytical models of how bitumen influences the cable’s mechanical properties, in particular the bending stiffness. A new laboratory instrument has been developed for establishing the viscoelastic properties of bitumen subject to equally large strains as in real-life cables. This paper presents the basic principle of the new instrument and derives how to calculate bitumen’s viscoelastic properties from the measurements logged by the instrument. The paper also models bitumen’s viscoelastic properties as function of strain amplitude, strain frequency, and bitumen temperature, using multi-variable data analysis. These models show that the viscoelastic properties are highly temperature dependent. Bitumen’s shear stress / shear strain amplitude ratio grows with increasing rate as the temperature decreases.

Much Ado About Fried Chicken: Abetting Aspiration or Respecting Autonomy?

2019 ◽  
Vol 28 (3) ◽  
pp. 1356-1362
Author(s):  
Laurence Tan Lean Chin ◽  
Yu Jun Lim ◽  
Wan Ling Choo
Keyword(s):  
Palliative Care ◽  
End Of Life ◽  
Multidisciplinary Team ◽  
Biopsychosocial Model ◽  
Family Members ◽  
Clinical Decisions ◽  
Goals Of Care ◽  
Complex Needs ◽  
Aspiration Risk ◽  
Patient Centric

Purpose Palliative care is a philosophy of care that encompasses holistic, patient-centric care involving patients and their family members and loved ones. Palliative care patients often have complex needs. A common challenge in managing patients near their end of life is the complexity of navigating clinical decisions and finding achievable and realistic goals of care that are in line with the values and wishes of patients. This often results in differing opinions and conflicts within the multidisciplinary team. Conclusion This article describes a tool derived from the biopsychosocial model and the 4-quadrant ethical model. The authors describe the use of this tool in managing a patient who wishes to have fried chicken despite aspiration risk and how this tool was used to encourage discussions and reduce conflict and distress within the multidisciplinary team.

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