Paper 2: Safety and Failure Analysis of Large Diesel Engine Pistons

1969 ◽  
Vol 184 (2) ◽  
pp. 8-16 ◽  
Author(s):  
D. J. White ◽  
L. R. Enderby
Keyword(s):  
Cast Iron ◽  
Diesel Engine ◽  
Failure Analysis ◽  
Diesel Engines ◽  
Fatigue Testing ◽  
Fatigue Tests ◽  
Safety Factors ◽  
Design For Safety ◽  
Theoretical Stress ◽  
Fatigue Failures

This paper describes investigations that were undertaken to identify the reasons for fatigue failures in cast iron and aluminium pistons of large diesel engines. The work involved experimental and theoretical stress analyses, and fatigue tests were made on specimens cut from actual pistons. It was found that four pistons which suffered fatigue failures had safety factors of 0·60, 0·68, 0·94, and 0·96, while three modified designs which performed satisfactorily were assessed to have safety factors of 1·1, 1·24, and 1·57. Special attention is drawn to the method of fatigue testing in which features typical of the piston are retained. While it is considered prudent to design for safety factors substantially in excess of unity, the results presented should promote confidence that this approach to the design of components is valid not only in this case but more generally.

Gigacycle Fatigue of Welded Joints of Structural Materials (A Review)

2016 ◽  
Vol 17 ◽  
pp. 14-30 ◽  
Author(s):  
Okechukwu P. Nwachukwu ◽  
Alexander V. Gridasov ◽  
Ekaterina A. Gridasova
Keyword(s):  
Fatigue Testing ◽  
Fatigue Behavior ◽  
Testing Machine ◽  
Structural Materials ◽  
Fatigue Tests ◽  
Material Defects ◽  
Graphite Cast Iron ◽  
Ultrasonic Fatigue ◽  
Materials Used ◽  
Fatigue Failures

This review looks into the state of gigacycle fatigue behavior of some structural materials used in engineering works. Particular attention is given to the use of ultrasonic fatigue testing machine (USF-2000) due to its important role in conducting gigacycle fatigue tests. Gigacycle fatigue behavior of most materials used for very long life engineering applications is reviewed.Gigacycle fatigue behavior of magnesium alloys, aluminum alloys, titanium alloys, spheroid graphite cast iron, steels and nickel alloys are reviewed together with the examination of the most common material defects that initiate gigacycle fatigue failures in these materials. In addition, the stage-by-stage fatigue crack developments in the gigacycle regime are reviewed. This review is concluded by suggesting the directions for future works in gigacycle fatigue.

scholarly journals Material evolution in critical parts of marine low speed engines

2015 ◽  
Vol 2015 (4) ◽  
pp. 65-72
Author(s):  
Владимир Рогалев ◽  
Vladimir Rogalev ◽  
Олег Чернявский ◽  
Oleg Chernyavskiy
Keyword(s):  
Cast Iron ◽  
Diesel Engine ◽  
Diesel Engines ◽  
Alloying Elements ◽  
Effective Pressure ◽  
Piston Rings ◽  
Engineering Plant ◽  
Low Speed ◽  
Material Chemistry ◽  
Materials Used

With the growth of average effective pressure in cylinders of marine lowspeed diesel engines the requirements increased to materials used for manufacturing their critical parts. This paper reports the dynamics of mechanical data changes in materials (steel and cast iron) of critical parts in diesel engines by the example of produce of the Bryansk engineering plant. From 1961 till 2008 the Bryansk engineering plant is the only manufacturer of powerful marine low-speed diesel engines in Russia. Diesel engines were being built under licence of “MAN Burmeister Diesel” Co. Diesel engines manufactures in different years differ with forcing degree. A diesel engine with a higher forcing degree has a higher value of mean effective pressure. In the paper there are shown types of diesel engines manufactured by the Bryansk engineering plant and is shown the evolution of mechanical data of cylinder iron bushes, piston rings, steel components of a bed frame, crankshafts. It is pointed out that the application of new steel and cast iron kinds should follow considerable changes in the design of marine low-speed diesel engines of the type 6DKRN 50/200-14 of compact modification. The conclusion is drawn of that with the growth of a forcing degree in diesel engines the mechanical data of steel and cast iron will increase at the expense of material chemistry changes by means of the introduction of alloying elements and application of modern metallurgical equipment for qualitative billet manufacturing.

Fatigue Strength of Ductile Iron in Ultra-High Cycle Regime

2014 ◽  
Vol 874 ◽  
pp. 43-48 ◽  
Author(s):  
Robert Ulewicz ◽  
František Nový ◽  
Jacek Selejdak
Keyword(s):  
Cast Iron ◽  
Fatigue Strength ◽  
Ductile Iron ◽  
High Frequency ◽  
Fatigue Testing ◽  
Testing Machine ◽  
Fatigue Tests ◽  
Essential Factor ◽  
Equipment Safety ◽  
Sn Curve

Machine and equipment safety is the most essential factor that determines the choice of a particular material used in the construction phase. Failure analyses in engineering praxis demonstrate that nearly 90 % of all cases of failures are caused by fatigue. For popular technical applications such as cars and trains, the durability expected for some components ranges from 108to 1010loading cycles. However, only few studies have been carried out for more than 107cycles. The SN curve in the ultra-wide life region must be determined in order to ensure actual fatigue strength and safety of these components. This paper presents the results obtained from fatigue tests carried out by means of a high-frequency fatigue testing machine for the three grades of ductile iron: with ferritic-pearlitic matrix (GGG50), with pearlitic-ferritic matrix (GGG60) and ADI cast iron in the range from 106up to 1010cycles.

scholarly journals Consideration of the transient material behavior under variable amplitude loading in the fatigue assessment of nodular cast iron using the strain-life approach

2020 ◽  
Author(s):  
Jan Hesseler ◽  
Jörg Baumgartner ◽  
Christoph Bleicher
Keyword(s):  
Cast Iron ◽  
Residual Stresses ◽  
Fatigue Testing ◽  
Cyclic Hardening ◽  
Nodular Cast Iron ◽  
Fatigue Tests ◽  
Material Behavior ◽  
Strong Impact ◽  
Static Creep ◽  
Cyclic Relaxation

The consideration of realistic load assumptions is important for the fatigue design of highly stressed nodular cast iron components for wind energy application. Especially in case of overloads causing elastic-plastic deformation, residual stresses may have a strong impact on fatigue life. In strain-controlled fatigue tests with constant and variable amplitudes, the influence of overloads on the lifetime was investigated. The overload was applied with the objective to create high tensile residual stresses. During fatigue testing the transient material behavior, cyclic hardening, cyclic relaxation of the residual stresses as well as quasi static creep effects, of the EN-GJS-400-18-LT was recorded and evaluated. To quantify the influence of the transient material behavior on the calculated lifetime, fatigue analyses are carried out with the strain-life approach, both with and without consideration of the transient material behavior. The results show that conservative damage sums are derived if the transient material behavior, especially the relaxation of tensile residual stresses, is neglected.

Failure Analysis on the GCr15 Bearing Steel and the 20CrMo Carburized Steel Nuts of the Ball Screw Pair

2014 ◽  
Vol 651-653 ◽  
pp. 29-33 ◽  
Author(s):  
Yu Hong Gai ◽  
Ye Yan ◽  
Cheng Nan Li ◽  
Bao Min Li ◽  
Wei Du ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Fatigue Testing ◽  
Contact Fatigue ◽  
Bearing Steel ◽  
Fatigue Tests ◽  
Ball Screw ◽  
Carburized Steel ◽  
Gcr15 Bearing Steel ◽  
Steel Balls ◽  
Testing Condition

Failure analysis on the GCr15 bearing steel and the 20CrMo carburized steel nuts was performed after two sets of fatigue tests of GD8020×1100 ball screw pair. By means of scanning electron microscopy observation, energy dispersive analysis and microhardness testing, it is found that there is an obvious indentation, slight pitting and microcracks on the raceway of the GCr15 bearing steel nut and shows the characteristics of contact fatigue failure. The nonuniformity of microstructure and the lower carbon and chromium content in the indentation, leading to local lower hardness, account for the nut failure. While the raceway of the 20CrMo carburized steel nut is more rough with scratches caused by the damaged steel balls so as to show the characteristics of wear failure. Therefore there are different failure ways for the different nuts made by different steels and heat treatments under the same fatigue testing condition.

scholarly journals Fault Detection of Diesel Engine Air and after-Treatment Systems with High-Dimensional Data: A Novel Fault-Relevant Feature Selection Method

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 259
Author(s):  
Qilan Ran ◽  
Yedong Song ◽  
Wenli Du ◽  
Wei Du ◽  
Xin Peng
Keyword(s):  
Genetic Algorithm ◽  
Diesel Engine ◽  
Fault Detection ◽  
Correlation Analysis ◽  
Canonical Correlation Analysis ◽  
Diesel Engines ◽  
Canonical Correlation ◽  
High Dimensional Data ◽  
High Dimensional ◽  
Relevant Variables

In order to reduce pollutants of the emission from diesel vehicles, complex after-treatment technologies have been proposed, which make the fault detection of diesel engines become increasingly difficult. Thus, this paper proposes a canonical correlation analysis detection method based on fault-relevant variables selected by an elitist genetic algorithm to realize high-dimensional data-driven faults detection of diesel engines. The method proposed establishes a fault detection model by the actual operation data to overcome the limitations of the traditional methods, merely based on benchmark. Moreover, the canonical correlation analysis is used to extract the strong correlation between variables, which constructs the residual vector to realize the fault detection of the diesel engine air and after-treatment system. In particular, the elitist genetic algorithm is used to optimize the fault-relevant variables to reduce detection redundancy, eliminate additional noise interference, and improve the detection rate of the specific fault. The experiments are carried out by implementing the practical state data of a diesel engine, which show the feasibility and efficiency of the proposed approach.

scholarly journals Fatigue Testing of Wearable Sensing Technologies: Issues and Opportunities

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4070
Author(s):  
Andrea Karen Persons ◽  
John E. Ball ◽  
Charles Freeman ◽  
David M. Macias ◽  
Chartrisa LaShan Simpson ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Prediction Models ◽  
Fatigue Testing ◽  
Low Cycle Fatigue ◽  
Wearable Sensors ◽  
Fatigue Tests ◽  
Proof Of Concept ◽  
Cycle Fatigue ◽  
Wearable Sensing ◽  
Failure Data

Standards for the fatigue testing of wearable sensing technologies are lacking. The majority of published fatigue tests for wearable sensors are performed on proof-of-concept stretch sensors fabricated from a variety of materials. Due to their flexibility and stretchability, polymers are often used in the fabrication of wearable sensors. Other materials, including textiles, carbon nanotubes, graphene, and conductive metals or inks, may be used in conjunction with polymers to fabricate wearable sensors. Depending on the combination of the materials used, the fatigue behaviors of wearable sensors can vary. Additionally, fatigue testing methodologies for the sensors also vary, with most tests focusing only on the low-cycle fatigue (LCF) regime, and few sensors are cycled until failure or runout are achieved. Fatigue life predictions of wearable sensors are also lacking. These issues make direct comparisons of wearable sensors difficult. To facilitate direct comparisons of wearable sensors and to move proof-of-concept sensors from “bench to bedside,” fatigue testing standards should be established. Further, both high-cycle fatigue (HCF) and failure data are needed to determine the appropriateness in the use, modification, development, and validation of fatigue life prediction models and to further the understanding of how cracks initiate and propagate in wearable sensing technologies.

Effect of altitude conditions on combustion and performance of a turbocharged direct-injection diesel engine

2021 ◽  
pp. 095440702110262
Author(s):  
Zhentao Liu ◽  
Jinlong Liu
Keyword(s):  
Diesel Engine ◽  
High Altitude ◽  
Diesel Engines ◽  
Direct Injection ◽  
Pressure Rise ◽  
Ambient Conditions ◽  
Allowable Limit ◽  
Spray Formation ◽  
Direct Injection Diesel Engine ◽  
And Performance

Market globalization necessitates the development of heavy duty diesel engines that can operate at altitudes up to 5000 m without significant performance deterioration. But the current scenario is that existing studies on high altitude effects are still not sufficient or detailed enough to take effective measures. This study applied a single cylinder direct injection diesel engine with simulated boosting pressure to investigate the performance degradation at high altitude, with the aim of adding more knowledge to the literature. Such a research engine was conducted at constant speed and injection strategy but different ambient conditions from sea level to 5000 m in altitude. The results indicated the effects of altitude on engine combustion and performance can be summarized as two aspects. First comes the extended ignition delay at high altitude, which would raise the rate of pressure rise to a point that can exceed the maximum allowable limit and therefore shorten the engine lifespan. The other disadvantage of high-altitude operation is the reduced excess air ratio and gas density inside cylinder. Worsened spray formation and mixture preparation, together with insufficient and late oxidation, would result in reduced engine efficiency, increased emissions, and power loss. The combustion and performance deteriorations were noticeable when the engine was operated above 4000 m in altitude. All these findings support the need for further fundamental investigations of in-cylinder activities of diesel engines working at plateau regions.

Failure Analysis on Diesel-Engine Valve Springs

2009 ◽  
Vol 9 (4) ◽  
pp. 329-334 ◽  
Author(s):  
Zhi-Wei Yu ◽  
Xiao-Lei Xu
Keyword(s):  
Diesel Engine ◽  
Failure Analysis ◽  
Engine Valve
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