Failure Analysis Of A Cracked Cylinder Block Assembly Of An Aircraft Brake System

The failure problem of brakes in the bogie of the working part on a tamper wagon is brought out in this paper. Braking process under its working condition is simulated and the comparison is done between the motion simulation and the working principle of brake system. FEM analysis by ABAQUS is done to analyze the front braking beam which is suffering bigger force. Stress distribution from the FEM analysis is discussed to explain the failure places happen in reality. In the end, an arbitrary crack is assumed and the fatigue life of beam is work out to give a prediction of failure.

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Failure Analysis of Diesel Engine Intake Valve

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.385-387.29 ◽

2008 ◽

Vol 385-387 ◽

pp. 29-32

Author(s):

Ali Göksenli ◽

Barlas Eryürek

Keyword(s):

Diesel Engine ◽

Failure Analysis ◽

Safety Factor ◽

Chemical Properties ◽

Failure Surface ◽

Cylinder Block ◽

Intake Valve ◽

Valve Seat ◽

Stress Increase ◽

High Fatigue

In this study failure analysis of a mini van diesel engine intake valve is analyzed in detail. Failure occurred at the groove of the valve. First mechanical and chemical properties of the valve are determined. After visual investigation of the fracture surface it is concluded that fracture occurred due to fatigue. Damaged valve, valve seat, cylinder block and piston surface is investigated and construed. Failure constituted 300 kilometers after the rectification of the engine. Therefore rectification and assembly steps of valve and engine parts are analyzed in detail. Considering assembly, design and working conditions of the engine, stresses occurring at the failure surface are calculated. Endurance limit and fatigue safety factor is determined. Because of high fatigue safety factor, reasons for failure are investigated and effects causing stress increase at groove of the valve are established. These effects are faulty assembly of the valve and valve seat causing a high impact effect. In conclusion effect of impact ratio on stress increase is explained.

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Failure Analysis With the Scanning Electron Microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100095662 ◽

1972 ◽

Vol 30 ◽

pp. 482-483

Author(s):

John R. Devaney

Keyword(s):

Electron Microscope ◽

Scanning Electron Microscope ◽

Integrated Circuits ◽

Failure Analysis ◽

High Reliability ◽

Military Applications ◽

Small Structure ◽

Useful Life ◽

Insight Into ◽

Scanning Electron

Occasionally in history, an event may occur which has a profound influence on a technology. Such an event occurred when the scanning electron microscope became commercially available to industry in the mid 60's. Semiconductors were being increasingly used in high-reliability space and military applications both because of their small volume but, also, because of their inherent reliability. However, they did fail, both early in life and sometimes in middle or old age. Why they failed and how to prevent failure or prolong “useful life” was a worry which resulted in a blossoming of sophisticated failure analysis laboratories across the country. By 1966, the ability to build small structure integrated circuits was forging well ahead of techniques available to dissect and analyze these same failures. The arrival of the scanning electron microscope gave these analysts a new insight into failure mechanisms.

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Using the scanning electron microscope for failure analysis of high density magnetic media

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100126755 ◽

1987 ◽

Vol 45 ◽

pp. 392-393

Author(s):

Evelyn R. Ackerman ◽

Gary D. Burnett

Keyword(s):

Electron Microscope ◽

Scanning Electron Microscope ◽

Failure Analysis ◽

High Density ◽

Magnetic Media ◽

Specific Data ◽

Retrieval Systems ◽

Operating Environments ◽

The Media ◽

Scanning Electron

Advancements in state of the art high density Head/Disk retrieval systems has increased the demand for sophisticated failure analysis methods. From 1968 to 1974 the emphasis was on the number of tracks per inch. (TPI) ranging from 100 to 400 as summarized in Table 1. This emphasis shifted with the increase in densities to include the number of bits per inch (BPI). A bit is formed by magnetizing the Fe203 particles of the media in one direction and allowing magnetic heads to recognize specific data patterns. From 1977 to 1986 the tracks per inch increased from 470 to 1400 corresponding to an increase from 6300 to 10,800 bits per inch respectively. Due to the reduction in the bit and track sizes, build and operating environments of systems have become critical factors in media reliability.Using the Ferrofluid pattern developing technique, the scanning electron microscope can be a valuable diagnostic tool in the examination of failure sites on disks.

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