Failure Analysis and Material Selection - Research Proposal Example

Name Name of Instructor Subject Institution Date Background information of the materials failure Although with time many studies have been made to counter the effect caused by the failure of materials, much economic loss and human demoralizing has been realized with the change in this technology. Failure analysis is the key factor that is being used as the subject of analysis to enable engineers learns the new ways to solve the problems encountered [9]. This analysis is used in the use of mechanical and also structural failures to analyze the failure of any given material. The use of materials has been dated 2250 BC which proves that the materials used are always prone to failure and thus need to improve their strength and other working properties [3]. Based on the failure of many bridges that have been built and failed the use of advanced technology is the basic way to advance the construction and developing of the new and better materials for the designs. Operations of the materials The working principles of the materials are based on the stress analysis which defines the working and the operations of such materials. There are many reasons that result in failure of materials in many occasions these, include; fatigue analysis, corrosion failures, stress corrosion cracking, ductile and brittle fractures, hydrogen embrittlement, liquid material embrittlement, and creep and stress rupture [3]. This analysis is provided by the analysis done by the engineers and the metallurgical consultants who have proper knowledge concerning the materials and the failure analysis. The expert opinions are provided by the material engineers who work in hand with the failure analysts. These have the duty to analyze the principles of operation of the materials and how they operate at different environments. Literature review Analysis of the potential causes of failure of the materials The accident which is used as the case study occurred on November fourth 2010 at 0157 UTC time. A code VH-OQA (OQA) was registered by the airbus A380 which operated as a Qantas flight. It had departed from the 20 centre runway at the Changi airport heading towards Sydney. It had 24 crew cabin and four hundred and forty passengers. This amounted to four hundred and sixty nine. There were two loud bangs which were heard by the crew as the aircraft flew seven thousand feet above the sea level. The crew members were provide with the radar vector and directed to go back and land in Singapore. Following this action, it is evident that, the materials have many defects that results into failure as recorded from many instances. Amongst these materials' failure may result from the following, design errors, improper materials, unforeseen operating conditions, assembly errors, misuse or abuse of the materials when making the designs , inadequate quality assurance, having discontinuities during the casting process and lastly if the materials have inadequate environmental protection/control [4]. These factors are the major causes of the material failure and thus much care should be put in place to ensure that failure of the materials is taken care off. Failure analysis is an important field in the sphere of engineering. It deals with analyzing the various causes of the material breakdown or malfunctioning. The cases studies from the previous occurrences of the incidences aid in the determination the characteristics of the phenomenon that occurred [9]. It is adept to have the background knowledge of the nature of a given material and its specific use. The choice of the material to be used depends on the purpose on which the given material would be used. It through such mitigations that the failure cause may be analysed and proper designs may be implemented in future. The procedures which were used for inspections may also be moderated to come up with better strategies which would be more efficient and failure detection. This has been exhibited across various fields such as construction field where the failure in the bridges, cathedrals and the viaducts have led to better designs of these structures. In analyzing failure procedures, the application of the stress analysis plays a major role in speculating the design parameters of a given component or system. This is because the, operating principles of a given component would rely on its capability to succumb a given stress [3]. Most materials follow Hooke’s law while others take a different trend. The hooks law permeates the strength of particular materials and the elasticities exhibited in these materials. The technique of Finite element method has aided in ascertaining discrete stresses of materials. In the field of aerospace, the use of safe life and the fail safe have assisted in the development of statistical structures that determine how long a given structure may last without having experienced failure in a given duration [7]. The material would have to undergo several inspections at a given time to prevent it from experiencing failures. Considering the fail safe approach, the structures are such that when one of the given components undergoes failure, there is an alternative load that provides redundancy to avert failure and provide the support till the next inspection is carried out. This is exhibited in the use of the suspenders and the belt that supports the trousers. The kind of loading that would be subjected to a particular loading has to be considered to ensure there is uniform loading in a given structure. In testing procedures, applications such as corrosion science, fracture mechanics and the fatigue research have become elemental in the design testing of various structures. The current trend has seen modern materials being enhanced to endure resistance through, improvement in the metallurgical field where better designs of the alloys have been brought up. This has been achieved through the alloying chemistry and enhanced processing of the materials [6]. The methodology involved in the analysis procedures entailed the revision of the modification of the NMSB 72 G595 and the engine characteristics of the oil feed stubs which had a misalignment. The engine required to be throttled back to an idle mode and the condition to be scrutinised for duration of about thirty seconds. A massive damage was observed which required the engine two to be fire bottled [7]. The final results indicated that engine 2 had failed whereas engine number one and four were in their failure mode. The message relayed from the ECAM indicated that there were failures in the electric busses one and two. The flight was also operating in the alternate mode. The wings slats indicated that they were not operating properly. Several messages had been conveyed about the breaking systems Failure may be exhibited through the fractography where the fractures may be observed on the surface either, by pure observation or by use of the microscope. The results which have emanated from the failure analysis have become vital in developing the codes and specifications that would govern various materials construction. An example is the (American Society foresting and materials) ASTM [7]. The codes are aimed at averting the previous failures and provide more guard on the operating conditions of the future materials design and manufacture. This can stipulate on the number of which the safety factor may be based on. This aids to ascertain the allowable stress of various materials. Study of the bent metal speaks and the wreakage reports aid in the analyzing of failure of various materials. The study of macrostructure and microstructure gives the overall modes of deformation that occurs in various materials. Macro structural defects lead to dents in various materials that occur on ductile materials such as Aluminium which is used in parts of aeroplane. Fig 1 indicating the ductility of materials and their fractures in the plane ( Sihgn, 1997 ) The shape of the engine at the time of the accident may elaborate whether the engine could have been powered or not. An incidence of the chalks ocean airways crash indicated that the failure was with the structural components. The failure of components depends on the knowledge of fibre pull out and the failure due to interfacial. Case studies Comet Air crash The comet aircraft had better performing characteristics as compared to the initial designs that relied on the propeller to be driven. However, after a couple of flights, this plane experienced a disaster that occurred while it was cruising at high altitude. The fuselage underwent an explosive fuselage which is strongly believed to have emanated as a result of fatigue cracking. This occurred due to the stresses on areas around the corners of the fuselage regions. The regions that were squarer exhibited more cracking as compared to the round corners. The fractographic markings indicated the presence of the fatigue crack growth. This scenario led to the cancelation in ordering of the new fleet making the Comet fleet to come to a halt. The design team noted the need to come up with a new design of the pressurized fuselage that would be able to debar the catastrophic depressurization. In 1987, an aircraft Boeing 707-300c with goods to Zambia from London, while preparing to land its right horizontal stabilizer separated with the elevator in flight, this led to crashing of the aircraft two miles away from the runway. The Pilot, co pilot and the flight engineer died. The aircraft was the first of the B-707-300c series convertible passenger/freighter production line with a total of 16,723 landings. The horizontal stabilizer as well as other parts of this aircraft had been designed with fail-safe approach though full scale fatigue testing of B-707-300c stabilizer had not yet been done. The fail-safe approach can only be failed safe if after failure of one of the component. The remaining components have the strength to support the applied loads. This example of a single redundant structure is fail-safe while the primary structure is intact, when it fails then the principle of safe-life obtains and it becomes priority to find the failure in primary structure before fail-safe members become are weakened. Since the strength reserves in the fail-safe are always well below those of intact structure, it means, in practice the failure should be found and required action taken within a short time o maintain safety of a fail-safe thus an adequate inspection program must be part of the total design to ensure that a failure is identified before weakening of strength of the fail safe structure can happen Hartford Coliseum The collapse of Hartford coliseum roof occurred after three year since its construction, in 1978 January. A triangular lattice steel space grid 360feet by300feet supported by four reinforced concrete pylons with spans of 270 feet and 210 feet was used to support the roof. Analysis showed that interaction of top chord compression members and bracing had a role in redistribution of load and eventual collapse. Certain compression members were braced against buckling in only one plane and as load increased the members broke out of the plane and redistributed load to other members, this scenario continued over the time until the remaining members were unable to the added stress because of the loads present that night the collapse happened. Back ground on the failure Analysis of the misaligned oil pipe could indicate the nature of the fracture. The adjacent area of the counter bore is believed to be the area of main concern where the source of failure may have originated from [2]. The measurement of the oil feed pipes may have been measured wrongly and it may be difficult to ascertain if it met the required specification. The modules inspected found out seven modules having their wall thickness being less than the required thickness. This led to the replacement of about three engines. To keep the safety of the airplane, air simulators tests were performed regarding the data which was obtained from the recorder. It is expected to have the final conclusion by July 2011. Mitigations arising ensured the 72-G595 would undergo two flights from the initial twenty. To enhance better performance of the engines, the European aviation ensured the Rolls Royce control units have been approved with the software updates. This aids in envisaging whenever the engine over speeds, the engine would be turned down before the failure of the disc takes place. The investigations indicated a misanormally with the manufacturing of the oil pipes of various engines. The poor process in the manufacturing of the stud pipes is believed to be one of the probable causes of the fatigue crack leading to the engine failure. This yields to the firing of the oil as a result of oil leakage. Stud pipes would feed the bearing structure having high pressure (IP) intermediately pressure with oil. The crack was observed to have occurred in areas that exhibited thinner sections as compared to the rest of other parts. The misalignment of the axial area of the counter-bore could be one of the probable cause of the cracking. The conjecture of misalignment could probably have produced the presence of localised thinning occurring on the walls of the pipes. The power plants, propellers and the landing gears obtained it the aeroplanes play significant roles. They are designed in such a manner that they would avert chances of failure. The initial failure enables the establishment of safety standards. The major aim in the design systems is to avoid dangers associated with machine failures [7]. The dire need to learn from the previous failures enables engineers to learn lessons where they went wrong. It is apparent that the risks decisions have to be made to ensure that safety standards are adhered. Some sectors of scientist believed the problem to be the sole role of the technical issue that could be isolated from the rest of technology. Probabilistic assessment requires the determination of the future occurrence of accidents. The major challenge that lies is the ability to identify various failure modes that may be experienced. Material selection Material analysis Fatigue failures Many engineering components and systems possess low chances of exhibiting failure. Despite this, when the failure occurs, they are usually catastrophic. The low probability of failure is a result of the preclusion of several experiments carried out before a given system operates. This makes certification to be paramount in the computational models carried out on these systems. The use of conditional failure provides information about a variation in the random variables that goes hand in hand with a given failure [3]. This approach suffices the purposes of enhancing better engineering designs as well as validating the various mathematical models that find their applications in the computation of the models and their reliability. Conditional failure analysis would provide the graphical techniques from the conditional failures that would have been analysed. This technique focuses on the fatigue growth giving the result which may be evaluated in the validation of the model. Engineering systems design depends on various uncertainties that would cause the prediction of a certain component. The failure probability of a density function may be characterised by integral function as shown in equation (i) of a given failure function. The range of the values has to be identified in the random variables . (i) The F would define the failure domain in which  The conditional; failure density would be referred to as f(x/F) = f(x)[xg(x) Read More

It deals with analyzing the various causes of the material breakdown or malfunctioning. The cases studies from the previous occurrences of the incidences aid in the determination the characteristics of the phenomenon that occurred [9]. It is adept to have the background knowledge of the nature of a given material and its specific use. The choice of the material to be used depends on the purpose on which the given material would be used. It through such mitigations that the failure cause may be analysed and proper designs may be implemented in future.

The procedures which were used for inspections may also be moderated to come up with better strategies which would be more efficient and failure detection. This has been exhibited across various fields such as construction field where the failure in the bridges, cathedrals and the viaducts have led to better designs of these structures. In analyzing failure procedures, the application of the stress analysis plays a major role in speculating the design parameters of a given component or system.

This is because the, operating principles of a given component would rely on its capability to succumb a given stress [3]. Most materials follow Hooke’s law while others take a different trend. The hooks law permeates the strength of particular materials and the elasticities exhibited in these materials. The technique of Finite element method has aided in ascertaining discrete stresses of materials. In the field of aerospace, the use of safe life and the fail safe have assisted in the development of statistical structures that determine how long a given structure may last without having experienced failure in a given duration [7].

The material would have to undergo several inspections at a given time to prevent it from experiencing failures. Considering the fail safe approach, the structures are such that when one of the given components undergoes failure, there is an alternative load that provides redundancy to avert failure and provide the support till the next inspection is carried out. This is exhibited in the use of the suspenders and the belt that supports the trousers. The kind of loading that would be subjected to a particular loading has to be considered to ensure there is uniform loading in a given structure.

In testing procedures, applications such as corrosion science, fracture mechanics and the fatigue research have become elemental in the design testing of various structures. The current trend has seen modern materials being enhanced to endure resistance through, improvement in the metallurgical field where better designs of the alloys have been brought up. This has been achieved through the alloying chemistry and enhanced processing of the materials [6]. The methodology involved in the analysis procedures entailed the revision of the modification of the NMSB 72 G595 and the engine characteristics of the oil feed stubs which had a misalignment.

The engine required to be throttled back to an idle mode and the condition to be scrutinised for duration of about thirty seconds. A massive damage was observed which required the engine two to be fire bottled [7]. The final results indicated that engine 2 had failed whereas engine number one and four were in their failure mode. The message relayed from the ECAM indicated that there were failures in the electric busses one and two. The flight was also operating in the alternate mode. The wings slats indicated that they were not operating properly.

Several messages had been conveyed about the breaking systems Failure may be exhibited through the fractography where the fractures may be observed on the surface either, by pure observation or by use of the microscope. The results which have emanated from the failure analysis have become vital in developing the codes and specifications that would govern various materials construction. An example is the (American Society foresting and materials) ASTM [7]. The codes are aimed at averting the previous failures and provide more guard on the operating conditions of the future materials design and manufacture.

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