Frequency effect in the fatigue of the aluminum alloy D16T at elevated temperatures and with local stress concentration

1976 ◽  
Vol 11 (3) ◽  
pp. 355-356 ◽  
Author(s):  
A. V. Karlashov ◽  
V. P. Tokarev ◽  
V. V. Sazonov
Keyword(s):  
Aluminum Alloy ◽  
Stress Concentration ◽  
Elevated Temperatures ◽  
Local Stress ◽  
Frequency Effect ◽  
Alloy D16t ◽  
Local Stress Concentration ◽  
Aluminum Alloy D16t

Determination of DC06+ZE Sheet Crack Cause

2016 ◽  
Vol 368 ◽  
pp. 121-125
Author(s):  
Pavel Kejzlar ◽  
Tomáš Pilvousek ◽  
Michal Tregler
Keyword(s):  
Stress Concentration ◽  
Tensile Stress ◽  
Deep Drawing ◽  
Crack Formation ◽  
Local Stress ◽  
Local Deformation ◽  
Local Stress Concentration ◽  
Bcc Lattice ◽  
Hard Particles

The present work deals with determination of the cause of crack occurring in a part of car body manufactured from deep-drawing sheet. UHR-SEM, EDS, EBSD and measurement of microhardness were used for evaluation of the structure, local deformation and crack formation mechanism. A material analysis discovered foreign particles in the material. These particles were identified as MgAl2O4 with BCC lattice. The occurrence of these hard particles led to local stress concentration, decrease in mechanical strength and sheet breach due to tensile stress during deformation.

Permeability Improvement Technology of Directional Hydraulic Fracturing in Low Permeability

2014 ◽  
Vol 599-601 ◽  
pp. 385-390 ◽  
Author(s):  
Xue Xi Chen ◽  
Rui Qing Bi ◽  
Wen Guang Jin ◽  
Yong Xu
Keyword(s):  
Stress Concentration ◽  
Hydraulic Fracturing ◽  
Maximum Concentration ◽  
Local Stress ◽  
Field Application ◽  
Low Permeability ◽  
Pressure Relief ◽  
Local Stress Concentration ◽  
Directional Hydraulic Fracturing ◽  
Better Than

According to the conventional fracturing could easily lead to the local stress concentration of coal, the effect of pressure relief and permeability improvement is not ideal. The mechanism of directional hydraulic fracturing is analyzed and the parameters such as the layout of directional hole, the fracturing hole sealing, the minimum cracking pressure are discussed, then the field application tests are carried out. The results show that the directional hydraulic fracturing effect is better than that of ordinary fracturing hole and the maximum concentration and the average drainage scalar is respectively 3.75 times and 4 times of the ordinary hole pumping gas fracturing effects. The effect of permeability improvement is remarkable.

Effect of Coal Loading Conditions on Structural Characteristics of LFTS

2019 ◽  
Author(s):  
Hiroaki Eto ◽  
Koji Iizuka ◽  
Ryo Nishigochi ◽  
Tomoki Ikoma ◽  
Yasuhiro Aida ◽  
...  
Keyword(s):  
Stress Concentration ◽  
Loading Condition ◽  
Local Stress ◽  
Asia Pacific ◽  
Linear Potential ◽  
Detailed Model ◽  
Local Stress Concentration ◽  
East Kalimantan ◽  
Wave Response ◽  
Bulk Carriers

Abstract Indonesia is a main country supplying coal in the Asia-Pacific region, it is important to ensure a stable coal supply to Japan. Because the topography of the seabed near East Kalimantan Island, Indonesia’s main coal production area, is shallow, it is difficult for bulk carriers to reach the coast. Therefore, Large-Scale Floating Coal Transshipment Station (LFTS) was proposed, which will be used as a relay base between coal-barging barges from land and bulk carriers offshore. Installing an LFTS offshore from East Kalimantan is expected to improve coal transport productivity. LFTS can store coal equivalent to five times the capacity of one bulk carrier (total 500,000T), and can accommodate 2 bulk carriers at the same time during offloading. The scale of LFTS is 590m × 160m. The LFTS has a flat spread and the elastic behavior becomes the dominant Structure. The upper part of the LFTS is different rigidity partly because the partition wall to be loaded by dividing the coal into each quality is provided. Loaded coal not only changes the draft of the LFTS but also greatly deforms the LFTS and is expected to cause local stress concentration on the structural members. Therefore, this paper investigates wave response characteristics and stress characteristics with the coal loading of the LFTS, and then evaluation of structural strength by limit state design method. In this study, linear potential theory and the finite element method (FEM) were used to analyze the static hydroelastic motion under various coal loading condition and wave response of LFTS. And, to grasp the local stress concentration occurring inside the LFTS by using the response results, a detailed model modeling a complicated internal structure was prepared. Zooming analysis which is a method of giving the deformation result by the whole model of LFTS as forced displacement to the local detailed model was carried out. As a result, depending on the coal loading condition and wave conditions, it became clear that LFTS will be in a tough situation.

Endurance of the aluminum alloy D16T under high-frequency stressing in various media

1976 ◽  
Vol 11 (2) ◽  
pp. 224-225
Author(s):  
N. L. Pozen ◽  
B. A. Gryaznov ◽  
B. A. Lyashenko
Keyword(s):  
Aluminum Alloy ◽  
High Frequency ◽  
Alloy D16t ◽  
Aluminum Alloy D16t

Finite Element Analysis of Aluminum Alloy Pitting Stress Concentration

2012 ◽  
Vol 538-541 ◽  
pp. 1664-1669
Author(s):  
Li Hui ◽  
Ying Ying Zhang ◽  
Liang Xu ◽  
Song Zhou ◽  
Yan Wang
Keyword(s):  
Finite Element ◽  
Aluminum Alloy ◽  
Stress Concentration ◽  
Fatigue Crack Initiation ◽  
Measurement Data ◽  
Local Stress ◽  
Element Analysis ◽  
Corrosion Pit ◽  
Corrosion Pits ◽  
Corrosion Time

Based on measurement data and the specific morphology of corrosion pit, three-dimensional finite element model of the corrosion damage specimen is established. Then the local stress condition of corrosion pits is given making use of finite element method, the results of stress concentration due to corrosion pits are also obtained, we can compare the stress concentration arised from the corrosion pit on aluminum alloy specimens in different corrosion time. Results show that the corrosion pits produce stress concentration and become the source of fatigue crack initiation and propagation. With the increasing of corrosion time, the pits get deeper and deeper, and the stress concentration gets more serious near the pits.

Stress Intensity Factor for Corner Cracks of Pressurized Tees

1980 ◽  
Vol 102 (1) ◽  
pp. 121-123 ◽  
Author(s):  
M. A. Mohamed ◽  
J. Schroeder
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Stress Concentration ◽  
Intensity Factor ◽  
Local Stress ◽  
Numerical Techniques ◽  
Intensity Factors ◽  
Local Stress Concentration ◽  
Corner Cracks ◽  
Good Agreement

A method based on local stress concentration is employed to estimate stress intensity factors for corner cracks at the crotch corner of pressurized tees. The method yields results which are in good agreement with data obtained using other advanced numerical techniques.

Stress-Chemistry Mechanism of Mortars Made with Steel Slag Sand

2010 ◽  
Vol 163-167 ◽  
pp. 899-903
Author(s):  
Yun Xia Lun ◽  
Shao Shun Liu ◽  
Ming Kai Zhou ◽  
Xiao Fan Liu
Keyword(s):  
Stress Concentration ◽  
Volume Expansion ◽  
Steel Slag ◽  
Local Stress ◽  
Local Stress Concentration ◽  
Chemistry Method ◽  
Expansion Behavior ◽  
Volume Increment ◽  
Mineral Components ◽  
Free Cao

A stress-chemistry method was used to investigate the expansion behavior of mortars made with steel slag sand (SSM). The results indicated that periclase and free CaO were the main mineral components resulted in expansion of SSM by means of volume increment and local stress concentration after hydration. So it can be concluded that stress concentration arised from enrichment and uneven distribution of expansile mineral components was the main reason resulted in the volume expansion of SSM. Model of expansion of SSM was built according to the characteristics of crack and types of versicolor particles.

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