<p>By today’s date there are a lot of companies that are in great need of restructuring their paperwork in a more organized way. This can be excellent arranged with the help of properly constructed computer software. The aviation industry is no exception, but actually a good example of this. Täby Air Maintenance (TAM) is a company which is situated in Örebro. Their main business is aircraft maintenance on a variety of aircraft models. TAM has so far handled their work by hand or with the help of a majority of small computer programmes. The information has now become too abundant and the different kinds of software being used are no longer a working tool for the company. There is therefore a demand for an exhaustive programme which has the capacity to take care of all parts in logistics and production. The purpose is to examine and evaluate three different makes of software and form a recommendation to TAM of which one suits their needs the best. The software was Airsoft, MX System and System Airline Management (SAM). The evaluation has been performed with the help of demo versions of the programmes, manuals and support from contacts at the different manufacturers. The programmes were initially dealt with one at a time and then compared towards each other and towards the demands from TAM. The software which in the end was recommended was SAM, and the decision was based on a number of reasons. The main reason was the user friendliness of the software - the fact that its logical structure makes it easy for its user to swiftly understand the concept and thus learn how to use it quickly. This results in profits, both in time and money.</p> / <p>Idag är många företag i trängande behov av att strukturera upp sitt pappersarbete på ett mer ordnat sätt. Detta kan ske på ett effektivt sätt med ett anpassat och ändamålsenligt strukturerat datorprogram. Flygbranschen är inget undantag, snarare ett bra exempel på detta. Täby Air Maintenance (TAM) är ett företag som är beläget i Örebro och utför underhåll på flygplan i varierande storlek. TAM har hittills skött arbetet för hand och med hjälp av ett flertal mindre datorprogram. Informationen har dock blivit alldeles för omfångsrik och de olika programmen är inte längre ett fungerande instrument för verksamheten. Det krävs därför ett heltäckande program som har kapaciteten att ta hand om alla delar, såväl logistik som produktion. Syftet är att undersöka tre olika program och ge en rekommendation på det som passar företaget bäst. Programmen är Airsoft, MX System och System Airline Management (SAM). Undersökningen har utförts med hjälp av demoversioner, manualer och stöd från kontaktpersoner hos tillverkarna. Programmen undersöktes först var för sig och därefter jämfördes de mot varandra och mot TAMs krav. Det program som rekommenderades var SAM. Detta beror på en mängd orsaker, där den främsta orsaken var programmets användarvänlighet - det faktum att dess logiska uppbyggnad gör det lätt för användaren att snabbt kunna sätta sig in i strukturen och därmed lättare kunna lära sig att använda det. Detta i sin tur ger vinster i både tid och pengar.</p>

<p>An engineering firm which handles and constructs drawings needs well defined routines and structures which should be homogeneous through all the different departments. A common drawing system results in better quality and cooperation between the departments.</p><p>SAS Technical Services (STS) did not have a common drawing system which had led to development of different routines in the different regions and departments. Requested was development of new routines regarding engineering drawings, such as drawing numbering structure, revision and subscription routines, which standards to adhere to, custom made drawing templates and management of the drawings with belonging documents.</p><p>Each requested task was broken into minor tasks and analyzed. Solutions by different leading engineering companies were used for comparison and ideas.</p><p>All the tasks were collected and organized in one single document which is the result of the thesis; a drawing instruction.</p><p>The drawing instruction will after a learning phase ease the work for the STS engineers as all necessary information can be found in one single place. Also, work with contractors will be time-saving as the instruction can be handed out for guidance.</p> / <p>En ingenjörsfirma som hanterar och skapar mängder med ritningar behöver väldefinierade rutiner och strukturer som är homogena genom hela bolaget. Ett gemensamt ritningssystem resulterar i bättre kvalitet och bättre samarbete mellan de olika avdelningarna.</p><p>SAS Technical Services (STS) hade inte ett gemensamt ritningssystem vilket har lett till att de olika avdelningarna har utvecklat olika rutiner rörande ritningar. Önskemålet var utvecklande av nya rutiner rörande ingenjörsritningar såsom ritningsnumreringsstruktur, revisions- och prenumerationsrutiner, vilka standarder som skall följas, egna ritningsmallar och skötsel av ritningar med tillhörande dokument.</p><p>Varje önskad uppgift blev uppdelad i mindre uppgifter och analyserad. Lösningar från olika ledande ingenjörsbolag användes för jämförelse och idéer.</p><p>Alla uppgifterna samlades och organiserades i ett och samma dokument som är resultatet av detta arbete; en ritningsinstruktion.</p><p>Ritningsinstruktionen kommer efter en inlärningsfas underlätta arbetet för ingenjörerna på STS eftersom all nödvändig information nu finns på ett och samma ställe. Arbeten med entreprenörer vill också bli underlättande eftersom instruktionen kan delas ut för vägledning.</p>

<p>For every operating condition of an internal combustion engine there exists an optimal spark timing, called maximum brake torque (MBT), which maximises the output torque and the efficiency of the engine. Traditionally MBT timing is implemented as an open-loop control where the ignition timing is found by using a combination of static lookup tables and sensor information. With a direct closed-loop control from the combustion process the performance of internal combustion engines could be improved. The thesis investigates if it is possible to estimate the MBT timing from the ionization current for every operating condition of a spark ignited engine where the operating conditions are defined by the engine parameters lambda, internal exhaust gas recirculation, engine load, engine speed and spark advance.</p><p>First an investigation of how much loss of torque an error from the MBT position corresponds to is made. Then the influence of the engine parameters on the shape of the ionization current was studied. Last different peak pressure position (PPP) estimating algorithms are presented and a new technique is developed where an engine operating point dependant part of the ionization current is used depending on the current operating condition of the engine. Two of the presented PPP estimating algorithms are then complemented with this technique and the results look promising.</p>

Composite structures can lower the weight of an airliner significantly. Due to the higher process complexity and the high material cost, however, the low weight often comes with a significant increase in production cost. The application of cost-effective design strategies is one mean to meet this challenge. In this thesis, a simplified form of direct operating cost is suggested as a comparative value that in combination with multidisciplinary optimization enables the evaluation of a design solution in terms of cost and weight. The proposed cost optimization framework takes into account the manufacturing cost, the non-destructive testing cost and the lifetime fuel consumption based on the weight of the aircraft, thus using a simplified version of the direct operating cost as the objective function. The manufacturing cost can be estimated by means of different techniques. For the proposed optimization framework, feature-based parametric cost models prove to be most suitable. Paper A contains a parametric study in which a skin/stringer panel is optimized for a series of cost/weight ratios (weight penalties) and material configurations. The weight penalty (defined as the specific lifetime fuel burn) is dependent on the fuel consumption of the aircraft, the fuel price and the viewpoint of the optimizer. It is concluded that the ideal choice of the design solution is neither low-cost nor low-weight but rather a combination thereof. Paper B proposes the inclusion of non-destructive testing cost in the design process of composite components, and the adjustment of the design strength of each laminate according to inspection parameters. Hence, the scan pitch of the ultrasonic testing is regarded as a variable, representing an index for the guaranteed material quality. It is shown that the cost for non-destructive testing can be lowered if the quality level of the laminate is assigned and adjusted in an early design stage. In Paper C and Paper D the parameters of the manufacturing processes are upgraded during the cost optimization of the component. In Paper C, the framework is extended by the cost-efficient adaptation of parameters in order to reflect the situation when machining an aluminum component. For different weight penalties, the spar thickness and stringer geometry of the provided case study vary. In addition, another cutter is chosen with regard to the modified shape of the stringer. In Paper D, the methodology is extended to the draping of composite fabrics, thus optimizing not only the stacking layup, but also the draping strategy itself. As in the previous cases, the design alters for different settings of the weight penalty. In particular, one can see a distinct change in fiber layup between the minimum weight and the minimum cost solution. Paper E summarizes the work proposed in Papers A-D and provides a case study on a C-spar component. Five material systems are used for this case study and compared in terms of cost and weight. The case study shows the impact of the weight penalty, the material cost and the labor rate on the choice of the material system. For low weight penalties, for example, the aluminum spar is the most cost-effective solution. For high weight penalties, the RTM system is favorable. The paper also discusses shortcomings with the presented methodology and thereby opens up for future method developments. / QC 20100723 / European Framework Program 6, project ALCAS, AIP4-CT-2003-516092 / Nationella flygtekniska forskningsprogrammet (NFFP) 4, project kostnadseffektiv kompositstruktur (KEKS)

Engine components are exposed to vibrations which may lead to fatigue damage. Accurate dynamic simulations are necessary especially during the development process, in order to find a satisfactory component. Currently Scania uses a standard method for dynamic calculations that is based on a frequency response approach. A measured or calculated excitation yields a certain response through the transfer function of the system. The transfer function is obtained through an eigenfrequency calculation and an experience-based estimate of the modal damping. An obvious drawback of this method is that the estimated modal damping strongly affects the calculated response of the system. In this thesis, the method outlined above is compared to an alternative, so-called, inverse method in which the excitation of the system is calculated using a measured response. The advantage is that the modal damping does not affect the result directly since the excitation has been adjusted according to the response. As a demonstration object a charge air pipe and its bracket are used. Acceleration response data is collected from an engine vibration measurement. The calculated safety factor of the demonstration object is reasonable for both the standard method and the inverse method. An estimate of the quality of the model is obtained for the inverse method through statistical measures, which is not the case for the standard method. The excitation for the inverse method is adjusted to the estimated modal damping which is a major advantage since damping is notoriously difficult to quantify in engineering practice. The inverse method has proven to be a useful simulation method for calculations when a prototype of the engine component of interest already exists.

<p>The work in this thesis focuses on the use of explicit finite element analysis (FEA) in the modelling of fluid-structure interaction of panel-water impacts. Paper A, considers modelling of a two-dimensional rigid wedge impacting a calm water surface. From analytical methods and results of a systematic parameter study a generalised approach for determination of fluid discretization and contact parameters in the modelling of arbitrary hull-water impact situations is developed and presented. In paper B the finite element modelling methodology suggested in paper A is evaluated for elastic structures by a convergence study of structural response and hydrodynamic load. The structural hydroelastic response is systematically studied by a number of FE-simulations of different impact situations concerning panel deadrise, impact velocity and boundary conditions. In paper B a tentative method for dynamic characterization is also derived. The results are compared with other published results concerning hydroelasticity in panel water impacts. The long-term goal of this work is to develop design criteria, by which it can be determined whether the loading situation of a certain vessel type should be regarded as quasi-static or dynamic, and which consequence on the design a dynamic loading has.</p>

By today’s date there are a lot of companies that are in great need of restructuring their paperwork in a more organized way. This can be excellent arranged with the help of properly constructed computer software. The aviation industry is no exception, but actually a good example of this. Täby Air Maintenance (TAM) is a company which is situated in Örebro. Their main business is aircraft maintenance on a variety of aircraft models. TAM has so far handled their work by hand or with the help of a majority of small computer programmes. The information has now become too abundant and the different kinds of software being used are no longer a working tool for the company. There is therefore a demand for an exhaustive programme which has the capacity to take care of all parts in logistics and production. The purpose is to examine and evaluate three different makes of software and form a recommendation to TAM of which one suits their needs the best. The software was Airsoft, MX System and System Airline Management (SAM). The evaluation has been performed with the help of demo versions of the programmes, manuals and support from contacts at the different manufacturers. The programmes were initially dealt with one at a time and then compared towards each other and towards the demands from TAM. The software which in the end was recommended was SAM, and the decision was based on a number of reasons. The main reason was the user friendliness of the software - the fact that its logical structure makes it easy for its user to swiftly understand the concept and thus learn how to use it quickly. This results in profits, both in time and money. / Idag är många företag i trängande behov av att strukturera upp sitt pappersarbete på ett mer ordnat sätt. Detta kan ske på ett effektivt sätt med ett anpassat och ändamålsenligt strukturerat datorprogram. Flygbranschen är inget undantag, snarare ett bra exempel på detta. Täby Air Maintenance (TAM) är ett företag som är beläget i Örebro och utför underhåll på flygplan i varierande storlek. TAM har hittills skött arbetet för hand och med hjälp av ett flertal mindre datorprogram. Informationen har dock blivit alldeles för omfångsrik och de olika programmen är inte längre ett fungerande instrument för verksamheten. Det krävs därför ett heltäckande program som har kapaciteten att ta hand om alla delar, såväl logistik som produktion. Syftet är att undersöka tre olika program och ge en rekommendation på det som passar företaget bäst. Programmen är Airsoft, MX System och System Airline Management (SAM). Undersökningen har utförts med hjälp av demoversioner, manualer och stöd från kontaktpersoner hos tillverkarna. Programmen undersöktes först var för sig och därefter jämfördes de mot varandra och mot TAMs krav. Det program som rekommenderades var SAM. Detta beror på en mängd orsaker, där den främsta orsaken var programmets användarvänlighet - det faktum att dess logiska uppbyggnad gör det lätt för användaren att snabbt kunna sätta sig in i strukturen och därmed lättare kunna lära sig att använda det. Detta i sin tur ger vinster i både tid och pengar.

For every operating condition of an internal combustion engine there exists an optimal spark timing, called maximum brake torque (MBT), which maximises the output torque and the efficiency of the engine. Traditionally MBT timing is implemented as an open-loop control where the ignition timing is found by using a combination of static lookup tables and sensor information. With a direct closed-loop control from the combustion process the performance of internal combustion engines could be improved. The thesis investigates if it is possible to estimate the MBT timing from the ionization current for every operating condition of a spark ignited engine where the operating conditions are defined by the engine parameters lambda, internal exhaust gas recirculation, engine load, engine speed and spark advance. First an investigation of how much loss of torque an error from the MBT position corresponds to is made. Then the influence of the engine parameters on the shape of the ionization current was studied. Last different peak pressure position (PPP) estimating algorithms are presented and a new technique is developed where an engine operating point dependant part of the ionization current is used depending on the current operating condition of the engine. Two of the presented PPP estimating algorithms are then complemented with this technique and the results look promising.

An engineering firm which handles and constructs drawings needs well defined routines and structures which should be homogeneous through all the different departments. A common drawing system results in better quality and cooperation between the departments. SAS Technical Services (STS) did not have a common drawing system which had led to development of different routines in the different regions and departments. Requested was development of new routines regarding engineering drawings, such as drawing numbering structure, revision and subscription routines, which standards to adhere to, custom made drawing templates and management of the drawings with belonging documents. Each requested task was broken into minor tasks and analyzed. Solutions by different leading engineering companies were used for comparison and ideas. All the tasks were collected and organized in one single document which is the result of the thesis; a drawing instruction. The drawing instruction will after a learning phase ease the work for the STS engineers as all necessary information can be found in one single place. Also, work with contractors will be time-saving as the instruction can be handed out for guidance. / En ingenjörsfirma som hanterar och skapar mängder med ritningar behöver väldefinierade rutiner och strukturer som är homogena genom hela bolaget. Ett gemensamt ritningssystem resulterar i bättre kvalitet och bättre samarbete mellan de olika avdelningarna. SAS Technical Services (STS) hade inte ett gemensamt ritningssystem vilket har lett till att de olika avdelningarna har utvecklat olika rutiner rörande ritningar. Önskemålet var utvecklande av nya rutiner rörande ingenjörsritningar såsom ritningsnumreringsstruktur, revisions- och prenumerationsrutiner, vilka standarder som skall följas, egna ritningsmallar och skötsel av ritningar med tillhörande dokument. Varje önskad uppgift blev uppdelad i mindre uppgifter och analyserad. Lösningar från olika ledande ingenjörsbolag användes för jämförelse och idéer. Alla uppgifterna samlades och organiserades i ett och samma dokument som är resultatet av detta arbete; en ritningsinstruktion. Ritningsinstruktionen kommer efter en inlärningsfas underlätta arbetet för ingenjörerna på STS eftersom all nödvändig information nu finns på ett och samma ställe. Arbeten med entreprenörer vill också bli underlättande eftersom instruktionen kan delas ut för vägledning.

Problematik med utmattningsbrott är känt sedan början på 1800-talet och fenomenet har studerats sedan dess. Efter lång tids arbete har man hittat en metodik för att ta fram analytiska beräkningsmodeller samt säkra och noggranna livslängdsberäkningar för stålkonstruktioner. Syftet med detta arbete har varit att undersöka en marin ångpannas utmattningshållfasthet under loppet av dess ekonomiska livslängd. I den här studien har en analytisk beräkning gjorts på en marin ångpannas utmattningslivslängd med hjälp av DNV ́s regler för klassifikation av fartyg samt Europeiska tryckkärlsnormen. I studien har författarna tagit hänsyn till ångpannans tryckvariationer, temperaturvariationer samt den marina ångpannans yttre påverkan från fartygets rörelse i vattnet och de resulterande hävkrafterna. Detta för att med hög tillförlitlighet (konfidens) kunna värna om människoliv, natur och miljö, fysisk egendom (fartyg samt last), operativa tillgänglighet samt lagar och regler. / Problems with fractures due to fatigue have been known since the early 19th century, and the phenomenon has been studied since then. After long periods of work, a methodology has been found to develop analytical fatigue calculation models for steel structures. The purpose of this work has been to investigate the fatigue assessments of marine boilers during it ́s economic lifetime. In this study, an analytical calculation has been made of the marine boiler using DNV's ship classification rules and the European pressure vessel standard. In the study, the authors have taken into account the boilers pressure variations, temperature variations, and the marine boiler's external impact from the vessel's motion in the water and the resulting forces. In order to be able to protect human life, nature and the environment, physical property (ships and cargo), operational availability as well as laws and regulations, with high reliability (confidentiality).