Standard Test Methods for High-Temperature Characterization of Gypsum Boards and Panels

10.1520/c1795 ◽  
2016 ◽  
Author(s):  
Keyword(s):  
High Temperature ◽  
Test Methods ◽  
Standard Test

Stresses in Multilayered Ceramics Subjected to Biaxial Flexure Tests

2008 ◽  
Vol 606 ◽  
pp. 79-92 ◽  
Author(s):  
C.H. Hsueh
Keyword(s):  
Solid Oxide Fuel Cells ◽  
Closed Form ◽  
Analytical Description ◽  
Test Methods ◽  
Standard Test ◽  
Fracture Load ◽  
Closed Form Solutions ◽  
American Society ◽  
Biaxial Flexure

Although standard test methods for biaxial strength measurements of ceramics have been established and the corresponding formulas for relating the biaxial strength to the fracture load have been approved by American Society for Testing and Materials (ASTM) and International Organization for Standardization, respectively, they are limited to the case of monolayered discs. Despite the increasing applications of multilayered ceramics, characterization of their strengths using biaxial flexure tests has been difficult because the analytical description of the relation between the strength and the fracture load for multilayers subjected to biaxial flexure tests is unavailable until recently. Using ring-on-ring tests as an example, the closed-form solutions for stresses in (i) monolayered discs based on ASTM formulas, (ii) bilayered discs based on Roark’s formulas, and (iii) multilayered discs based on Hsueh et al.’s formulas are reviewed in the present study. Finite element results for ring-on-rings tests performed on (i) zirconia monolayered discs, (ii) dental crown materials of porcelain/zirconia bilayered discs, and (iii) solid oxide fuel cells trilayered discs are also presented to validate the closed-form solutions. With Hsueh et al.’s formulas, the biaxial strength of multilayered ceramics can be readily evaluated using biaxial flexure tests.

Effects of Thermal Cycling on Elastomers in High Temperature Coolant

2010 ◽  
Author(s):  
Daniel L. Hertz
Keyword(s):  
High Temperature ◽  
Thermal Cycling ◽  
Cooling System ◽  
Engine Performance ◽  
Test Methods ◽  
Standard Test ◽  
Radial Deformation ◽  
Seal Design ◽  
Vulcanized Rubber ◽  
Before And After

In the past ten years diesel engine performance has significantly increased in terms of kilowatts/litre (kW/L). These higher power density outputs create higher thermal loads on the cooling system and associated seals. While compatibility of elastomers in high temperature coolants has been studied and reported, the inevitable impact of thermal cycling on these elastomers is not well documented. This study examines the effects of thermal cycling in three general coolant categories on three different elastomers commonly considered for sealing hot engine coolants. The elastomers, by ASTM D1418 designation, are HNBR, FKM Type 2, and FEPM. The coolants are an organic acid technology (OAT) coolant, a propylene glycol premix coolant, and a corrosion inhibited de-ionized water. Normal service applications are characterized by an indefinite number of shutdowns and startups. Testing was designed to simulate such service. Aging periods incorporated ongoing 24 hour cycles: a 16 hour period to heat up and operate at 150°C, and an 8 hour period to cool off to ambient. O-rings, a common seal design, were subject to axial and radial deformation during testing. The o-rings’ sealing attributes were examined after four, ten, twenty, and forty cycles. Elastomeric properties were evaluated, before and after cyclical aging, in accordance with ASTM D1414-94 (“Standard Test Methods for Rubber O-rings”) and D412-06a (“Standard Test Methods for Vulcanized Rubber … - Tension”). Compressive stress relaxation (CSR) was evaluated using an in-house procedure, comporting with ASTM D6147-94.

Characterization of Bituminous, Intermediate-Level Waste Products

1988 ◽  
Vol 127 ◽  
Author(s):  
Z. Kopajtic ◽  
D. Laske ◽  
H. P. Linder ◽  
M. Mohos ◽  
M. Nellen ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Test Methods ◽  
Standard Test ◽  
Intermediate Level ◽  
Gas Generation ◽  
Γ Irradiation ◽  
Waste Products

ABSTRACTThe influence of γ-irradiation on the properties of two types of bituminous reprocessing waste has been studied. Standard test methods were adapted for use with radioactive samples. Measurements of penetration, gas generation, thermal stability and leaching of irradiated and non-irradiated samples have been compared.

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