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.

scholarly journals Optimal consumption of multiple goods in incomplete markets

2018 ◽  
Vol 55 (3) ◽  
pp. 810-822
Author(s):  
Oleksii Mostovyi
Keyword(s):  
Closed Form ◽  
Incomplete Markets ◽  
Existence And Uniqueness ◽  
Dual Problem ◽  
Optimal Consumption ◽  
Closed Form Solutions ◽  
Uniqueness Of The Solution ◽  
Incomplete Models

Abstract We consider the problem of optimal consumption of multiple goods in incomplete semimartingale markets. We formulate the dual problem and identify conditions that allow for the existence and uniqueness of the solution, and provide a characterization of the optimal consumption strategy in terms of the dual optimizer. We illustrate our results with examples in both complete and incomplete models. In particular, we construct closed-form solutions in some incomplete models.

Review of Test Methods for Evaluating Hydrogen Embrittlement Susceptibility of Materials

2004 ◽  
Author(s):  
Deanna J. Burwell ◽  
Michiel P. H. Brongers ◽  
John A. Beavers
Keyword(s):  
Hydrogen Embrittlement ◽  
Constant Load ◽  
Test Methods ◽  
Standard Test ◽  
Operating Conditions ◽  
General Motors ◽  
Hydrogen Fuel Cell ◽  
The Government ◽  
American Society ◽  
Safe Transport

For several decades, engineers and technicians responsible for safe transport and storage of hydrogen, in both the government and industry sectors, have had to contend with the problem of hydrogen embrittlement. Today, the problem of hydrogen embrittlement must be considered anew with the systems and environments emerging with the developing hydrogen fuel cell industry. This paper discusses several methods to test for the susceptibility of metallic materials to hydrogen embrittlement. The objective of this review is to assist engineers and designers in selecting hydrogen embrittlement test methods to simulate actual manufacturing and/or operating conditions while using appropriate specimen geometries. Reviewed are standard test methods from American Society for Testing and Materials (ASTM) International, British Aerospace Series (BSEN), and General Motors Engineering sources. These include constant load, rising step load, slow strain rate, inclined wedge, bend, disk pressure, and cantilever beam test methods. Information is provided on load and displacement characteristics, uses, a brief description, and required equipment for each test.

Structure Design, Kinematics and Grasp Constraint of a Metamorphic Robotic Hand for Meat Deboning Operation

2013 ◽  
Author(s):  
Guowu Wei ◽  
Vahid Aminzadeh ◽  
Evangelos Emmanouil ◽  
Jian S. Dai
Keyword(s):  
Closed Form ◽  
Structure Design ◽  
Robotic Hand ◽  
Meat Industry ◽  
Sensor Systems ◽  
Level Control ◽  
Closed Form Solutions ◽  
Low Level ◽  
Structure And Design

A four-fingered metamorphic robotic hand with a reconfigurable palm is presented in this paper with the application in deboning operation of meat industry. This robotic hand has a reconfigurable palm that generates changeable topology and augments dexterity and versatility for the hand. Mechanical structure and design of the robotic hand are presented and based on mechanism decomposition, kinematics of the metamorphic hand is investigated with closed-form solutions leading to the workspace characterization of the robotic hand. Based on the kinematics of the four-fingered metamorphic hand, utilizing product-of-exponentials formula, grasp map and grasp constraint of the hand are then formulated revealing the grasp robustness and manipulability performed by the metamorphic hand. A prototype of the four-fingered metamorphic hand is consequently fabricated and integrated with low level control and sensor systems leading to a scenario of applying the hand in the field of meat industry for deboning operation.

scholarly journals Entropy-regularized 2-Wasserstein distance between Gaussian measures

2021 ◽  
Author(s):  
Anton Mallasto ◽  
Augusto Gerolin ◽  
Hà Quang Minh
Keyword(s):  
Fixed Point ◽  
Closed Form ◽  
Numerical Study ◽  
Wasserstein Distance ◽  
Iteration Algorithm ◽  
Probability Measures ◽  
Gaussian Distributions ◽  
Closed Form Solutions ◽  
Special Cases

AbstractGaussian distributions are plentiful in applications dealing in uncertainty quantification and diffusivity. They furthermore stand as important special cases for frameworks providing geometries for probability measures, as the resulting geometry on Gaussians is often expressible in closed-form under the frameworks. In this work, we study the Gaussian geometry under the entropy-regularized 2-Wasserstein distance, by providing closed-form solutions for the distance and interpolations between elements. Furthermore, we provide a fixed-point characterization of a population barycenter when restricted to the manifold of Gaussians, which allows computations through the fixed-point iteration algorithm. As a consequence, the results yield closed-form expressions for the 2-Sinkhorn divergence. As the geometries change by varying the regularization magnitude, we study the limiting cases of vanishing and infinite magnitudes, reconfirming well-known results on the limits of the Sinkhorn divergence. Finally, we illustrate the resulting geometries with a numerical study.

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.

Sign in / Sign up

Export Citation Format

Share Document