Online Forecast of Fatigue Life in Welded Grider of Bridge Crane

2008 ◽  
Vol 44-46 ◽  
pp. 809-812
Author(s):  
Chang Hong Liu ◽  
Xin Tian Liu ◽  
Hu Huang ◽  
Li Hui Zhao
Keyword(s):  
Fatigue Crack ◽  
Crack Extension ◽  
Spline Interpolation ◽  
Fuzzy Reasoning ◽  
Bridge Crane ◽  
Ann Model ◽  
Interpolation Model ◽  
Anfis Model ◽  
Fatigue Crack Development ◽  
Order Spline

It is very important to forecast the fatigue crack development upon welded girder of bridge crane during use. When it happens, it will have a lot of clout with performance of enterprises. For security purpose in use, ANFIS model is built to predict the length of the fatigue crack extension about welded girder of bridge crane. Membership function is adjusted according to inputs and outputs of fuzzy reasoning, and appropriate fuzzy regulation numbers are chosen. The model which is closest to the real development of fatigue crack is built with the help of the If-Then rules. According to the result from the fatigue experiment of the welded girder of bridge crane, ANFIS model, ANN model and Three Order Spline Interpolation model are respectively built. After analysis and verification, it is obvious that ANFIS model is more accurate and feasible.

Piecewise Fifth Order Spline Interpolation for Line Heating Forming Process

2016 ◽  
Author(s):  
Henri Champliaud ◽  
Zhengkun Feng ◽  
David Provencher ◽  
Danick Tousignant ◽  
Javad Gholipour
Keyword(s):  
Finite Element ◽  
Flat Plate ◽  
Spline Interpolation ◽  
Finite Element Simulations ◽  
Thermal Gradients ◽  
Interpolation Model ◽  
Forming Process ◽  
Line Heating ◽  
Order Spline ◽  
Fifth Order

A fifth order piecewise spline interpolation model has been developed for computing the evolving geometry of a plate deformed by line heating thermal gradients. 3D formulations are presented and applied to continuously derivable geometries to demonstrate the capability of the methodology. Then the developed formulation is used to form gradually, with a sequence of heating lines, a 3D shape from an initially flat plate. The geometric results obtained from finite element simulations with three heating lines are used to illustrate where heating lines should be applied on a flat plate to achieve the intended geometry of a workpiece. Furthermore, it is shown that applying the developed piecewise fifth order spline interpolation model to the same flat plate produces results very close to the ones obtained from the thermal structural FE simulations.

scholarly journals FAST AND ACCURATE MULTI-FRAME SUPER-RESOLUTION OF SATELLITE IMAGES

2020 ◽  
Vol V-1-2020 ◽  
pp. 57-64
Author(s):  
J. Anger ◽  
T. Ehret ◽  
C. de Franchis ◽  
G. Facciolo
Keyword(s):  
Satellite Images ◽  
Spline Interpolation ◽  
Super Resolution ◽  
Interpolation Model ◽  
Resolution Method ◽  
Still Image ◽  
Small Satellites ◽  
High Resolution Image ◽  
Video Frames ◽  
Order Spline

Abstract. Recent constellations of small satellites, such as Planet’s SkySats, offer new acquisition modes where very short videos or bursts of images are acquired instead of a single still image. Compared to sequences of multi-date images, these sequences of consecutive video frames yield a large redundancy of information within the range of seconds. This redundancy enables to increase the spatial resolution using multi-frame super-resolution algorithms. In this paper, we propose a novel super-resolution method based on a high-order spline interpolation model that combines multiple low-resolution frames to produce a high-resolution image. Moreover this method can be implemented efficiently on GPU to process entire images from real satellite acquisitions. Synthetic and real experiments show that the proposed method is able to recover fine details, and measurements of the resulting resolution indicate a gain of 10 cm / pixel with respect to Planet’s SkySat standard imagery products.

Application of the R-Curve Concept to Fatigue Crack Growth

1978 ◽  
Vol 100 (4) ◽  
pp. 416-420 ◽  
Author(s):  
D. P. Wilhem ◽  
M. M. Ratwani
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Crack Extension ◽  
Stress Ratio ◽  
Cyclic Stress ◽  
Crack Growth Resistance ◽  
Resistance Curve ◽  
Cyclic Stress Ratio ◽  
Wide Range

Crack growth resistance for both static (rising load) and for cyclic fatigue crack growth has been shown to be a continuous function over a range of 0.1 μm to 10 cm in crack extension for 2024-T3 aluminum. Crack growth resistance to each fatigue cycle of crack extension is shown to approach the materials ordinary undirectional static crack resistance value when the cyclic stress ratio is zero. The fatigue crack extension is averaged over many cycles and is correlated with the maximum value of the crack tip stress intensity, Kmax. A linear plot of crack growth resistance for fatigue and static loading data shows similar effects of thickness, stress ratio, and other parameters. The effect of cyclic stress ratio on crack growth resistance for 2219 aluminum indicates the magnitude of differences in resistance when plotted to a linear scale. Prediction of many of these trends is possible using one of several available crack growth data correlating techniques. It appears that a unique resistance curve, dependent on material, crack orientation, thickness, and stress/physical environment, can be developed for crack extensions as small as 0.076 μm (3 μ inches). This wide range, crack growth resistance curve is seen of immense potential for use in both fatigue and fracture studies.

scholarly journals Fractographic Study of Marine Diesel Engine Connecting Rod Stud Bolt Crack

2021 ◽  
Vol 58 (4) ◽  
pp. 28-42
Author(s):  
K. Carjova ◽  
V. Priednieks ◽  
R. Klaucans ◽  
I. Irbe ◽  
A. Urbahs
Keyword(s):  
Fatigue Crack ◽  
Diesel Engine ◽  
Tensile Tests ◽  
Marine Diesel Engine ◽  
Connecting Rod ◽  
Worst Case ◽  
The People ◽  
Marine Diesel ◽  
Fatigue Rupture ◽  
Fatigue Crack Development

Abstract Failures of marine diesel engine components can lead to serious consequences for a vessel, cargo and the people on board a ship. These consequences can be financial losses, delay in delivery time or a threat to safety of the people on board. This is why it is necessary to learn about connecting rod bolt failures in order to prevent worst-case scenarios. This paper aims at determining the origin, velocity and the duration of fatigue crack development of a diesel alternator engine which suffered a significant failure of one of its mains, not long after a major overhaul had been completed and with less than 1000 running hours having elapsed. It was verified with fatigue rupture of one of the four connecting rod stud bolts. Tensile tests were performed in the remaining connecting rod bolts. During this procedure, another fatigue crack in an adjacent bolt was identified. The probable root case of damage, and at the end some final remarks are presented.

scholarly journals Fatigue Crack Extension in Four-point Bending Test for Steels Imitated Heat Affected Zone

2015 ◽  
Vol 64 (4) ◽  
pp. 323-329 ◽  
Author(s):  
Hidetoshi KOBAYASHI ◽  
Noboru KONDA ◽  
Joy-A-Ka SUTEP ◽  
Ketaro HORIKAWA ◽  
Takeshi YAMAUCHI
Keyword(s):  
Fatigue Crack ◽  
Heat Affected Zone ◽  
Crack Extension ◽  
Bending Test ◽  
Four Point Bending ◽  
Four Point Bending Test

Test Stand for Analysis of Fatigue Crack Propagation under Bending with Torsion

2008 ◽  
Vol 144 ◽  
pp. 90-93 ◽  
Author(s):  
Grzegorz Gasiak ◽  
Grzegorz Robak
Keyword(s):  
Fatigue Crack ◽  
Crack Propagation ◽  
Fatigue Crack Propagation ◽  
Digital Camera ◽  
Crack Propagation Rate ◽  
Propagation Rate ◽  
Test Stand ◽  
Crack Development ◽  
Fatigue Crack Propagation Rate ◽  
Fatigue Crack Development

The paper presents a test stand for measurements of fatigue crack propagation. The stand includes a fatigue machine MZGS–100 and a device for registration of the crack length. The test stand is equipped with a stereoscopic microscope with fluent magnification of 7× – 67.5×. The microscope can be applied for observation of fatigue crack development. The microscope is also equipped with a digital camera, which enables continuous observation of fatigue crack development on the computer monitor and it is not necessary to stop the machine. The test results obtained at this stand can be used for determination of fatigue life and fatigue crack propagation rate.

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