The relationship between hydrogen concentration behavior and local triaxial stress

2019 ◽  
Vol 2019 (0) ◽  
pp. S03128
Author(s):  
Toshihito OHMI ◽  
Rikuya NAKAHARA ◽  
Toshimitsu YOKOBORI
Keyword(s):  
Hydrogen Concentration ◽  
Triaxial Stress ◽  
Concentration Behavior ◽  
The Relationship

scholarly journals Measurement and Analysis of Hydrogen Distribution in Stress Environment Using Vickers Microhardness Technique

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Lei Gu ◽  
Jing Wang ◽  
Xiaoyang Li ◽  
Yanjun Zeng
Keyword(s):  
Hydrogen Concentration ◽  
Vickers Microhardness ◽  
Experimental Results ◽  
Hydrogen Distribution ◽  
Crack Propagation Direction ◽  
Measurement And Analysis ◽  
Stress Environment ◽  
Concentration Behavior ◽  
The Relationship ◽  
Microhardness Tester

In this paper, the stress distribution field in front of the crack tip was obtained by loading a modified WOL specimen using a bolt. Considering the relationship between microhardness and hydrogen content or internal stress in the metal, a model based on the change of microhardness increment is proposed to describe the trend of hydrogen concentration distribution in the stress environment. The agreement between theoretical model and experimental results is verified by the Vickers microhardness tester. Based on the model, there is a simple additive relationship between the hydrogen-induced microhardness increment and the stress-induced microhardness increment. Therefore, the microhardness tester can be employed to evaluate the hydrogen distribution in metals quantitatively. The experimental results demonstrated that the Vickers microhardness method has accurately revealed the hydrogen concentration behavior accurately in a known equibiaxial stress environment. The hydrogen distribution of specimens in the stress environment was analyzed by taking the change of the microhardness increment along the crack propagation direction of specimens as the indicator.

scholarly journals Existence and Concentration Behavior of Solutions of the Critical Schrödinger–Poisson Equation in R3

Mathematics ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 464
Author(s):  
Jichao Wang ◽  
Ting Yu
Keyword(s):  
Poisson Equation ◽  
Existence Result ◽  
Critical Growth ◽  
Singularly Perturbed ◽  
Singularly Perturbed Problem ◽  
Number Of Solutions ◽  
Concentration Behavior ◽  
The Relationship ◽  
Concentration Phenomenon

In this paper, we study the singularly perturbed problem for the Schrödinger–Poisson equation with critical growth. When the perturbed coefficient is small, we establish the relationship between the number of solutions and the profiles of the coefficients. Furthermore, without any restriction on the perturbed coefficient, we obtain a different concentration phenomenon. Besides, we obtain an existence result.

scholarly journals An Overview of Pre-ignition of Hydrogen Engine

2020 ◽  
pp. 1-7
Author(s):  
Yang Luo ◽  
Chuanhao Zhao
Keyword(s):  
Environmental Pollution ◽  
Hydrogen Concentration ◽  
Development Trend ◽  
Combustion Efficiency ◽  
Key Factors ◽  
Factors Affecting ◽  
Research Status ◽  
New Perspective ◽  
The Development Trend ◽  
The Relationship

Hydrogen engine has attracted much attention due to its high combustion efficiency, low hydrogen concentration requirement, low environmental pollution and fuel regeneration. But the key issue pre-ignition has hindered the development of hydrogen engines. In order to have a more in-depth understanding of pre-ignition, this paper reviews the mechanism of pre-ignition, the relationship between the nature of hydrogen and pre-ignition , the key factors affecting pre-ignition and the research status of pre-ignition, analyzes the development trend of hydrogen engine and provides a new perspective for the study of inhibiting pre-ignition.

Hydrogen concentration behavior of y - grooved weld joint based on a coupled analysis of heat transfer - thermal stress - hydrogen diffusion

2018 ◽  
Vol 9 (10) ◽  
pp. 677-683
Author(s):  
Go Ozeki ◽  
A. Toshimitsu Yokobori ◽  
Toshihito Ohmi ◽  
Tadashi Kasuya ◽  
Nobuyuki Ishikawa ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Stress ◽  
Hydrogen Concentration ◽  
Weld Joint ◽  
Hydrogen Diffusion ◽  
Coupled Analysis ◽  
Concentration Behavior

Modeling of Fiber Bragg Grating Hydrogen Sensor with Multiple Membranes

2015 ◽  
Vol 738-739 ◽  
pp. 15-18
Author(s):  
Ying Ting Luo ◽  
Hao Wu ◽  
Yong Huang ◽  
Xiong Li ◽  
Hong Tu Song ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Partial Pressure ◽  
Fiber Bragg Grating ◽  
Hydrogen Concentration ◽  
Linear Response ◽  
Hydrogen Sensor ◽  
Bragg Grating ◽  
Wavelength Shift ◽  
Low Concentration ◽  
The Relationship

This paper develops a multiple membranes fiber Bragg grating (FBG) hydrogen sensor and investigates the relationship between wavelength of FBG hydrogen sensor and ambient hydrogen concentration. A physical and mathematical model is built to explain the sensor behavior when it is subjected to the changes in hydrogen concentration and in temperature. The shifts in Bragg wavelengths of the Pd-coated FBG hydrogen sensor as a function of hydrogen partial pressure is obtained. Thus the developed FBG hydrogen sensor has a linear response to hydrogen in the low concentration range. Tests were carried on to prove the relationship between wavelength shift and hydrogen concentration.

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