scholarly journals Clamping Voltage Characteristics and Accelerated Aging Behavior of CoCrTb-doped Zn/Pr-based Varistors with Sintering Temperature

2009 ◽  
Vol 10 (4) ◽  
pp. 125-130
Author(s):  
Ghoon-Woo Nahm
Keyword(s):  
Sintering Temperature ◽  
Accelerated Aging ◽  
Aging Behavior

Lifetime Prediction of Tires with Regard to Oxidative Aging5

2008 ◽  
Vol 36 (1) ◽  
pp. 63-79 ◽  
Author(s):  
L. Nasdala ◽  
Y. Wei ◽  
H. Rothert ◽  
M. Kaliske
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Temperature Distribution ◽  
Superposition Principle ◽  
Accelerated Aging ◽  
Material Model ◽  
Aging Behavior ◽  
Element Analysis ◽  
Material Parameters ◽  
Reaction Processes

Abstract It is a challenging task in the design of automobile tires to predict lifetime and performance on the basis of numerical simulations. Several factors have to be taken into account to correctly estimate the aging behavior. This paper focuses on oxygen reaction processes which, apart from mechanical and thermal aspects, effect the tire durability. The material parameters needed to describe the temperature-dependent oxygen diffusion and reaction processes are derived by means of the time–temperature–superposition principle from modulus profiling tests. These experiments are designed to examine the diffusion-limited oxidation (DLO) effect which occurs when accelerated aging tests are performed. For the cord-reinforced rubber composites, homogenization techniques are adopted to obtain effective material parameters (diffusivities and reaction constants). The selection and arrangement of rubber components influence the temperature distribution and the oxygen penetration depth which impact tire durability. The goal of this paper is to establish a finite element analysis based criterion to predict lifetime with respect to oxidative aging. The finite element analysis is carried out in three stages. First the heat generation rate distribution is calculated using a viscoelastic material model. Then the temperature distribution can be determined. In the third step we evaluate the oxygen distribution or rather the oxygen consumption rate, which is a measure for the tire lifetime. Thus, the aging behavior of different kinds of tires can be compared. Numerical examples show how diffusivities, reaction coefficients, and temperature influence the durability of different tire parts. It is found that due to the DLO effect, some interior parts may age slower even if the temperature is increased.

Accelerated aging behavior of an iron base amorphous alloy for 60 Hz application

1982 ◽  
Vol 18 (6) ◽  
pp. 1391-1393 ◽  
Author(s):  
A. Datta ◽  
R. Martis ◽  
S. Das
Keyword(s):  
Amorphous Alloy ◽  
Accelerated Aging ◽  
Aging Behavior ◽  
Iron Base

scholarly journals Effects of pretreatment on the soil aging behavior of rice husk fibers/polyvinyl chloride composites

BioResources ◽  
2018 ◽  
Vol 14 (1) ◽  
pp. 59-69 ◽  
Author(s):  
Lei Wang ◽  
Chunxia He ◽  
Xingxing Yang
Keyword(s):  
Polyvinyl Chloride ◽  
Rice Husk ◽  
Alkali Treatment ◽  
Accelerated Aging ◽  
Physical And Mechanical Properties ◽  
Microwave Treatment ◽  
Hydroxyl Groups ◽  
Aging Behavior ◽  
Plant Fibers ◽  
Soil Aging

The application of rice husk fibers (RHFs) to reinforce wood plastic composites has received appreciable attention. However, good interfacial adhesion is important for actual applications. Pretreatment methods can reduce the hydroxyl groups in plant fibers in order for them to bond with the plastic matrix. In this research, RHFs were pretreated by four methods: hydrothermal treatment (HT), microwave treatment (MT), alkali treatment (AT), and benzoylation treatment (BT). The effects of the four pretreatment methods on aging behavior of RHFs/polyvinyl chloride (PVC) composites was studied with simulated soil-accelerated aging conditions. Accelerated-soil aging caused the physical and mechanical properties of the composites to deteriorate. The ultimate performance of the composites was improved by the pretreated RHFs. The effectiveness ranking of the pretreatment methods was: benzoylation-treated RHFs reinforced PVC (BRRP) > alkali-treated RHFs reinforced PVC (ARRP) > hydrothermal-treated RHFs reinforced PVC (HRRP) > microwave-treated RHFs reinforced PVC (MRRP) > untreated RHFs reinforced PVC (URRP).

scholarly journals Advanced Test Setup for Accelerated Aging of Plastics by Visible LED Radiation

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4261
Author(s):  
Moritz Hemmerich ◽  
Jörg Meyer ◽  
Frank Walther
Keyword(s):  
High Power ◽  
Accelerated Aging ◽  
Sample Surface ◽  
Operating Parameters ◽  
Aging Behavior ◽  
Visible Radiation ◽  
Test Setup ◽  
Temperature Controlled ◽  
Optical Plastics

In this article, a newly developed test setup for the aging of optical plastics by visible radiation (450 nm) is presented. In addition to a comprehensive monitoring of the operating parameters and an efficient cooling of the high-power multiple chips on board the LEDs used, the plastic samples can be fully temperature-controlled, independent of the radiant power of the LED, due to fluid driven thermostatization. The sample surface temperatures and irradiance values were verified by in situ measurements and simulations. To validate the test setup, polycarbonate samples with well-known aging behavior were aged for 1896 h. By spectroscopic IR and UV/vis analysis of the samples at different aging times, known optical aging results of polycarbonate could be observed, which proves the intended operationality of the system.

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