Investigation and Diagnosis of Fatigue Cracks of Rib-to-Deck Welded Joints in Orthotropic Decks by the Phased Array Ultrasonic Scanner

2019 ◽  
Author(s):  
Masafumi Hattori ◽  
Koji Osada ◽  
Shoji Nojima ◽  
Hideyuki Tatematsu
Keyword(s):  
Welded Joints ◽  
Phased Array ◽  
Early Stage ◽  
Fatigue Cracks ◽  
Transportation Safety ◽  
Investigation Area ◽  
Diagnosis Method ◽  
Ultrasonic Scanner ◽  
Pavement Damage ◽  
The Cost

<p>Over the last decade, fatigue cracks have been observed at the rib-to-deck welded joints in many orthotropic decks in Japan. Considering the fatigue cracks can cause pavement damage and thus compromise transportation safety, it is necessary to detect and repair it at the early stage of its development. But the cracks occur from the weld route, it cannot be detected in early stage by visual check. Therefore, the phased array ultrasonic scanner (PAUS) has been developed as the method which can detect and measure the cracks with small size. And, it can simultaneously investigates the deck propagation type cracks and the weld bead propagation type cracks.</p><p>In this study, we propose a diagnosis method which considered the relation with selected countermeasures based on technological knowledge. And we propose an investigation area selecting method based on investigation speed of the PAUS which is confirmed by trial on the real bridge. In addition, the cost advantage by using the PAUS is estimated.</p>

scholarly journals Development of Asynchronous Motor Bearing Fault Diagnosis Method using TDA and FFNN

2019 ◽  
Vol 8 (10) ◽  
pp. 2622-2625
Keyword(s):  
Early Stage ◽  
Asynchronous Motor ◽  
Time Domain Analysis ◽  
Process Industry ◽  
Feed Forward Neural Network ◽  
Bearing Fault Diagnosis ◽  
Asynchronous Motors ◽  
Diagnosis Method ◽  
Detection And Diagnosis ◽  
The Cost

Asynchronous motors (AM) are life line of any process industry. Malfunctioning of AM at any stage of process leads the cost of finish product and decrease the efficiency of plant. Hence detection and diagnosis of AM failure at early stage is essential for timely maintenance and enhance the overall efficiency of the plant. The work present in this paper focuses on the bearing faults of AM. For this purpose experimental setup is developed in laboratory and results are based on experimental study carried out in laboratory by analysing AM generated vibration signals using time domain analysis (TDA) and feed forward neural network (FFNN).

scholarly journals Early stage propagation behavior of fatigue cracks in fillet welded joints.

1990 ◽  
pp. 135-143
Author(s):  
Chitoshi MIKI ◽  
Masahiro SAKANO ◽  
Yukihiro TOYODA ◽  
Tsutomu YOSFTIZAWA
Keyword(s):  
Welded Joints ◽  
Early Stage ◽  
Fatigue Cracks ◽  
Propagation Behavior

Insights into Transdermal Drug Delivery: Approaches for Redressal of a Burgeoning Issue of Osteoporosis

2020 ◽  
Vol 20 (10) ◽  
pp. 1682-1695
Author(s):  
Foziyah Zakir ◽  
Kanchan Kohli ◽  
Farhan J. Ahmad ◽  
Zeenat Iqbal ◽  
Adil Ahmad
Keyword(s):  
Drug Delivery ◽  
Transdermal Delivery ◽  
Oral Delivery ◽  
Calcium Absorption ◽  
Early Stage ◽  
Osteoporotic Fractures ◽  
The Novel ◽  
Systemic Delivery ◽  
Primary Focus ◽  
The Cost

Osteoporosis is a progressive bone disease that remains unnoticed until a fracture occurs. It is more predominant in the older age population, particularly in females due to reduced estrogen levels and ultimately limited calcium absorption. The cost burden of treating osteoporotic fractures is too high, therefore, primary focus should be treatment at an early stage. Most of the marketed drugs are available as oral delivery dosage forms. The complications, as well as patient non-compliance, limit the use of oral therapy for prolonged drug delivery. Transdermal delivery systems seem to be a promising approach for the delivery of anti-osteoporotic active moieties. One of the confronting barriers is the passage of drugs through the SC layers followed by penetration to deeper dermal layers. The review focuses on how anti-osteoporotic drugs can be molded through different approaches so that they can be exploited for the skin to systemic delivery. Insights into the various challenges in transdermal delivery and how the novel delivery system can be used to overcome these have also been detailed.

scholarly journals Methodology for the Concept Design of Locally Reinforced Composites

2021 ◽  
Vol 11 (16) ◽  
pp. 7246
Author(s):  
Julius Moritz Berges ◽  
Georg Jacobs ◽  
Sebastian Stein ◽  
Jonathan Sprehe
Keyword(s):  
Cost Estimation ◽  
Structural Design ◽  
Early Stage ◽  
Parameter Study ◽  
Great Effort ◽  
Concept Design ◽  
Cost Weight ◽  
Reinforced Plastics ◽  
Fiber Reinforced Plastics ◽  
The Cost

Locally load-optimized fiber-based composites, the so-called tailored textiles (TT), offer the potential to reduce weight and cost compared to conventional fiber-reinforced plastics (FRP). However, the design of TT has a higher complexity compared to FRP. Current approaches, focusing on solving this complexity for multiple objectives (cost, weight, stiffness), require great effort and calculation time, which makes them unsuitable for serial applications. Therefore, in this paper, an approach for the efficient creation of simplified TT concept designs is presented. By combining simplified models for structural design and cost estimation, the most promising concepts, regarding the cost, weight, and stiffness of TT parts, can be identified. By performing a parameter study, the cost, weight, and stiffness optima of a sample part compared to a conventional FRP component can be determined. The cost and weight were reduced by 30% for the same stiffness. Applying this approach at an early stage of product development reduces the initial complexity of the subsequent detailed engineering design, e.g., by applying methods from the state of the art.

scholarly journals Grid Parity Analysis of China’s Centralized Photovoltaic Generation under Multiple Uncertainties

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1814
Author(s):  
Libo Zhang ◽  
Qian Du ◽  
Dequn Zhou
Keyword(s):  
Power Generation ◽  
Early Stage ◽  
Electricity Price ◽  
Grid Parity ◽  
Industry Environment ◽  
External Conditions ◽  
Generation Costs ◽  
Time Price ◽  
The Cost ◽  
Installed Capacity

The cost of centralized photovoltaic (CPV) power generation has been decreasing rapidly in China. However, the achievement of grid parity is full of uncertainties due to changes in policies and the industry environment. In order to explore the time, price, and external conditions in which grid parity can be achieved, we create the improved grey GM (1, 1) model to estimate the installed capacity over the next 10 years, and apply a learning curve to predict the cost of CPV generation. In the analysis of grid parity, we compare the benchmark price of coal power and the price under the market-oriented mechanism with CPV. The results show that China’s CPV industry will enter the early stage of maturity from 2020 onwards; with the help of benchmark investment, the grid parity of CPV may be achieved in 2022 at the earliest and 2025 at the latest. After 2025, the photovoltaic electricity price will be generally lower than the coal electricity price under marketization. By 2030, CPV power generation costs will reach US $0.05/kWh, the accumulative installed capacity will exceed 370 GW, and the uncertainties will lead to a cumulative installed gap of nearly 100 GW.

Plastic Slip and Early Stage of Fatigue Damage in Polycrystals: Comparison between Experiments and Crystal Plasticity Finite Elements Simulations

2014 ◽  
Vol 891-892 ◽  
pp. 1711-1716 ◽  
Author(s):  
Loic Signor ◽  
Emmanuel Lacoste ◽  
Patrick Villechaise ◽  
Thomas Ghidossi ◽  
Stephan Courtin
Keyword(s):  
Fatigue Crack ◽  
Finite Elements ◽  
Crack Initiation ◽  
Fatigue Damage ◽  
Crystal Plasticity ◽  
Early Stage ◽  
Low Cycle Fatigue ◽  
Fatigue Cracks ◽  
Fatigue Crack Initiation ◽  
Plastic Slip

For conventional materials with solid solution, fatigue damage is often related to microplasticity and is largely sensitive to microstructure at different scales concerning dislocations, grains and textures. The present study focuses on slip bands activity and fatigue crack initiation with special attention on the influence of the size, the morphology and the crystal orientation of grains and their neighbours. The local configurations which favour - or prevent - crack initiation are not completely identified. In this work, the identification and the analysis of several crack initiation sites are performed using Scanning Electron Microscopy and Electron Back-Scattered Diffraction. Crystal plasticity finite elements simulation is employed to evaluate local microplasticity at the scale of the grains. One of the originality of this work is the creation of 3D meshes of polycrystalline aggregates corresponding to zones where fatigue cracks have been observed. 3D data obtained by serial-sectioning are used to reconstruct actual microstructure. The role of the plastic slip activity as a driving force for fatigue crack initiation is discussed according to the comparison between experimental observations and simulations. The approach is applied to 316L type austenitic stainless steels under low-cycle fatigue loading.

Application of Visual Beam Ultrasonic Phased Array in Inspection of Weld in Tubular Node

2015 ◽  
Author(s):  
Shaojun Wang ◽  
Xiaoying Tang ◽  
Houde Yu ◽  
Yaozhou Qian ◽  
Jun Cheng ◽  
...  
Keyword(s):  
Welded Joints ◽  
Phased Array ◽  
Sound Beam ◽  
Ultrasonic Sound ◽  
Array Technology ◽  
Coverage Model ◽  
Ultrasonic Phased Array ◽  
Arbitrary Section ◽  
Tubular Joint ◽  
Low Efficiency

Responding to complexity and particularity welding on the geometry of TKY tubular node, this paper constructs mathematical model of tubular joint weld of arbitrary section by simplifying the geometry structure, and draws welded joints and ultrasonic sound beam lines based on the actual specifications in order to solve the problems of low efficiency, positioning difficulty, missing inspection and etc. The computeraided simulation technology can realize the visualization in the beam coverage model of welded joints, which can commendably guide the design of ultrasonic phased array inspection and overcome the blindness of the instrument detection parameters, thus improving the effectiveness and pertinence of the actual detection. Study shows that it is beneficial to enhance the effectiveness of the detection tubular joint weld by employment of Visual beam and ultrasonic phased array technology.

The Aberdeen phased array: a real-time ultrasonic scanner with dynamic focus

1980 ◽  
Vol 18 (3) ◽  
pp. 335-343 ◽  
Author(s):  
R. D. Selbie ◽  
J. M. S. Hutchison ◽  
J. R. Mallard
Keyword(s):  
Real Time ◽  
Phased Array ◽  
Ultrasonic Scanner
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