A probabilistic methodology for the reliability analysis of composite rotor blades at the ply level was developed. The proposed methodology involves (i) the quantification of the uncertainties (physical, statistical and model) related to the material properties and the extreme aero-elastic loads based on experimental data as well as on 10 min load simulations respectively, (ii) the identification of the critical failure modes of the composite structure in terms of limit state functions and (iii) the selection of an appropriate reliability method to perform the analysis. It is pointed out that the reliability method should be able to handle the considerably large number of limit state function introduced by the ply level reliability approach and estimate the failure probability of the structure. To efficiently deal with the problem, an appropriate implementation of the Response Surface Method combined with crude Monte Carlo simulation was proposed. The methodology was implemented for two real rotor blade designs, namely a 30m Glass/Polyester and the 65m UPWIND reference rotor baled. Initially, calculations were performed for the first case study using a 3D shell FE formulation in a commercial probabilistic code. An efficient procedure was introduced to define the stochastic character of the concentrated loads acting on the 3D FE model starting from load time series of sectional stress resultants from aero-elastic beam simulations. For the first time such a detailed model was analyzed and assessed in a probabilistic base. Nevertheless, a considerable CPU time was in need for the performance of such a reliability analysis. The development of an efficient probabilistic tool capable to perform consecutive reliability analyses at the ply level of the composite rotor blade structure and prove valuable for the probabilistic design was carried out. To demonstrate the efficiency of the developed tool, the impact of various probabilistic modelling assumptions directly on the β-index value of a rotor blade design was studied. / Στην παρούσα διατριβή αναπτύχθηκε στοχαστική μεθοδολογία για την αποτίμηση αξιοπιστίας πτερυγίων ανεμογεννητριών από σύνθετα υλικά, στο επίπεδο της στρώσης, υπό ακραία στατική φόρτιση. Η προτεινόμενη μεθοδολογία περιλαμβάνει (i) την ποσοτικοποίηση αβεβαιοτήτων (φυσική, στατιστική και αβεβαιότητα μοντέλου) που σχετίζονται με τις βασικές παραμέτρους του πτερυγίου (υλικά και φορτία) στηριζόμενη σε ένα μεγάλο αριθμό πειραμάτων για τον προσδιορισμό των μηχανικών ιδιοτήτων του συνθέτου υλικού καθώς και 10-λεπτες αεροελαστικές χρονοσειρές για την ακραία στατική φόρτιση (ii) την αναγνώριση όλων των σημαντικών μηχανισμών αστοχίας της κατασκευής και την έκφρασή τους στη μορφή οριακών συναρτήσεων αστοχίας και (iii) την επιλογή μίας κατάλληλης μεθόδου αξιοπιστίας. Σημειώνεται ότι η μέθοδος αξιοπιστίας θα πρέπει να είναι ικανή να διαχειρίζεται ένα πολύ μεγάλο αριθμό οριακών συναρτήσεων αστοχίας όπως επιβάλει η ανάλυση αξιοπιστίας στο επίπεδο της στρώσης της κατασκευής. Για το σκοπό αυτό προτάθηκε μια κατάλληλη τροποποίηση της Response Surface Method τεχνικής η οποία συνδυάστηκε με την μέθοδο προσομοίωσης crude Monte Carlo. Η προτεινόμενη στοχαστική μεθοδολογία εφαρμόστηκε για την περίπτωση δυο πραγματικών πτερυγίων: ενός 30 m Glass/Polyester και του 65 m Glass/Epoxy (UPWIND) πτερυγίου. Η ανάλυση αρχικά πραγματοποιήθηκε σε γενικού σκοπού στοχαστικά εργαλεία κάνοντας χρήση τρισδιάστατου μοντέλου πεπερασμένων στοιχείων. Σημειώνεται ότι ο υπολογισμός των φορτίων από αεροελαστικούς κώδικες υλοποιείται πάντα στη βάση στοιχείων δοκού. Προτάθηκε επομένως διαδικασία για την στοχαστική αναπαράσταση των συγκεντρωμένων δυνάμεων που επιβάλλονται στο τρισδιάστατο μοντέλο πεπερασμένων στοιχείων του πτερυγίου στηριζόμενη σε χρονοσειρές εσωτερικών αντιδράσεων στη διατομή όπως εξάγονται από αεροελαστικους υπολογισμούς. Για πρώτη φορά σε αυτή την εργασία, πραγματοποιήθηκε η στοχαστική ανάλυση ενός τόσο λεπτομερειακού μοντέλου. Ωστόσο η παραπάνω προσέγγιση αποδείχτηκε αρκετά χρονοβόρα. Για το σκοπό αυτό αναπτύχθηκε υπολογιστικό εργαλείο ικανό να εκτελεί ένα μεγάλο αριθμό επαναλήψεων της προαναφερθείσας μεθοδολογίας και να φανεί χρήσιμο στο σχεδιασμό πτερυγίων με προκαθορισμένο επίπεδο αξιοπιστίας. Εξαιτίας της απλότητας της προετοιμασίας των δεδομένων εισόδου και της ταχύτητας επίλυσης, το νέο εργαλείο έδωσε τη δυνατότητα για τη μελέτη διαφόρων στατιστικών υποθέσεων που αφορούσαν τη δομική αξιοπιστία του πτερυγίου εξετάζοντας απευθείας τον δείκτη αξιοπιστίας β της κατασκευής.

Millimeterstora och svårupptäckta defekter kan uppstå internt i stora och komplexa gjutgods av Ti-6Al-4V, ibland går dessa oupptäckta tills detaljen genomgått mekanisk bearbetning och en stor kostnad redan har gått in i den. Dessa defekter och andra industriella olyckshändelser leder till ett behov av additiva reparationsmetoder där den för tillfället rådande metoden är TIG-svetsning. Denna metod reparerar defekterna men leder till oacceptabla restspänningar vilka kan åtgärdas med värmebehandling som i sin tur kan orsaka ytdefekten alpha case. Därav finns ett industriellt behov av reparationsmetoder som leder till mindre eller negligerbara restspänningsnivåer i reparerad detalj. Detta arbete utfört hos GKN Aerospace – Engine Products Sweden i Trollhättan analyserar eventuella förhållanden mellan parametrarna Effekt, Spot size, och Svetshastighet och de resulterande restspänningarna i ett lågparameterområde på materialet Ti-6Al-4V. En parameterrymd uppspänd av 17 parameteruppsättningar etablerades, svetsades och analyserades med mikrografi. Ur denna rymd simulerades de 8 yttre parametrarna med hjälpa av Finita Elementmetoden i svetssimuleringsmjukvaran MARC och ett förhållande mellan ingående parametrar och resulterande restspänningar undersöktes. En statistiskt säkerställd trend erhölls för att en minskad Svetshastighet leder till minskade tvärspänningar i mitten på en 20mm lång svetssträng. Detta är applicerbart för svetsar nyttjande start och stopplåtar. Det noterades även att en ökning i Effekt eller Spot size, eller en minskning utav svetshastigheten leder till att det av restspänningar utsatta området ökar i storlek. Detta är har implikationer för efterföljande värmebehandling i avgörandet av form och storlek på området som skall värmebehandlas. / Minute defects may occur in large complex Ti-6Al-4V castings, sometimes these are unnoticed until after machining and a high cost has been sunk into the part. These defect and other potential manufacturing mishaps render a need for additive repair methods. The state of the art method TIG welding can repair the parts but may leave unacceptable residual stresses, where the state of the art solution of Post Weld Heat Treatment might create a surface defect known as alpha case. Therefore there is a need for a repair weld method that results in lesser or negligible residual stresses. This thesis, carried out at GKN Aerospace – Engine Products Sweden, Trollhättan analyses the potential relationships between the laser welding parameters Power, Spot size, and Weld speed and the resulting residual stresses in a low energy parameter area on the material Ti-6Al-4V. A parameter box of 17 parameter sets was established, laid down and analyzed under micrograph, of this box the outer 8 parameter sets were simulated via the Finite Element Analysis welding simulation software MARC and a relationship between the input parameters and their resulting residual stresses was analyzed. A statistically significant trend was found supporting the claim that a decrease in transversal stresses in the center of a 20mm weld line is caused by an increase in Weld speed. This has implications for welds using run-on & run-of plates. It was also noted that an increase in Power or Spot size, or a decrease in Weld speed increases the area under residual stress; both as individual parameters and in synergy. This has implications for Post Weld Heat Treatment in determining the size and shape of the area in need of treatment.

This thesis deals with different optimization problems encountered in organic synthesis. The use of response surface, sequential simplex and PLS techniques, for simultanious optimization of yield and suppression of side reactions is investigated. This is illustrated by an example of enamine synthesis, were a side reaction was a serious problem. The problem of efficient screening to find suitable catalysts and solvents in new reactions is also investigated. Here, the use of principal properties as selection criterion, is demonstrated with a new process for the silylation of a,ß-unsaturated ketones. The extension of the new method to bis silylation of 1,2- and 1,3-diketones is demonstrated. The total synthesis of (±)-geosmin is investigated by an approach aimed to reduce the number of necessary steps involved. The suggested strategy, is to find compatible solvents through several transformations in the sequence to accomplish one-pot multistep reactions. In this context an improved method for the preparation of 1,10-dimethyl-l(9)-octalone-2 was established. Comparison with previously reported total syntheses of (±)-geosmin was done. / digitalisering@umu

New GC-MS method combined with SPE preconcentration step has been developed and optimized for the determination of selected fluorotelomer alcohols in aqueous samples by advanced statistical method in this thesis. 1H,1H,2H,2H-perfluoro-1-octanol (6:2 FTOH) and 1H,1H,2H,2H-perfluoro-1-decanol (8:2 FTOH) have been selected as the analytes. The influence of several factors, such as the sample volume, the carrier gas pressure, the sampling time and the injector temperature on the system response have been studied during the optimization. Utilizing the statistical software Minitab 16 and series of experiments, the optimal values of relevant factors and a suitable type of ionization were found for both analytes. Limits of detection of GC-MS method are 0.24 ng/mL for 6:2 FTOH and 0.42 ng/mL for 8:2 FTOH. Several factors, such as the type and the volume of conditioning agent, the speed of conditioning, the speed of sample flow, the method of column drying, the type and the volume of eluent have been tested for SPE. The optima of these factors were determined using Minitab 16 software. The extraction efficiency dependence on the concentration and volume of the stock solution was used to set the limitation of SPE for the determination of fluorotelomer alcohols. The maximum volume of sample equals to 400 mL...

A novel concept of multiple deterministic analyses is proposed to design safer and more damage-tolerant structures, particularly when excited by dynamic including seismic loading in time domain. Since the presence of numerous sources of uncertainty cannot be avoided or overlooked, the underlying risk is estimated to compare design alternatives. To generate the implicit performance functions explicitly, the basic response surface method is significantly improved. Then, several surrogate models are proposed. The advanced factorial design and Kriging method are used as the major building blocks. Using these basic schemes, seven alternatives are proposed. Accuracies of these schemes are verified using basic Monte Carlo simulations. After verifying all seven alternatives, the capabilities of the three most desirable schemes are compared using a case study. They correctly identified and correlated damaged states of structural elements in terms of probability of failure using only few hundreds of deterministic analyses. The modified Kriging method appears to be the best technique considering both efficiency and accuracy. Estimating the probability of failure, the post-Northridge seismic design criteria are found to be appropriate. After verifying the proposed method, a Site-Specific seismic safety assessment method for nonlinear structural systems is proposed to generate a suite of ground excitation time histories. The information of risk is used to design a structure more damage-tolerant. The proposed procedure is verified and showcased by estimating risks associated with three buildings designed by professional experts in the Los Angeles area satisfying the post-Northridge design criteria for the overall lateral deflection and inter-story drift. The accuracy of the estimated risk is again verified using the Monte Carlo simulation technique. In all cases, the probabilities of collapse are found to be less than 10% when excited by the risk-targeted maximum considered earthquake ground motion satisfying the intent of the code. The spread in the reliability indexes for each building for both limit states cannot be overlooked, indicating the significance of the frequency contents. The inter story drift is found to be more critical than the overall lateral displacement. The reliability indexes for both limit states are similar only for few cases. The author believes that the proposed methodology is an alternative to the classical random vibration and simulation approaches. The proposed site-specific seismic safety assessment procedure can be used by practicing engineers for routine applications. The proposed reliability methodology is not problem-specific. It is capable of handling systems with different levels of complexity and scalability, and it is robust enough for multi-disciplinary routine applications. In order to show the multi-disciplinary application of the proposed methodology, the probability of failure of lead-free solders in Ball Grid Array 225 surface-mount packaging for a given loading cycle is estimated. The accuracy of the proposed methodology is verified with the help of Monte Carlo simulation. After the verification, probability of failure versus loading cycles profile is calculated. Such a comprehensive study of its lifetime behavior and the corresponding reliability analyses can be useful for sensitive applications.

O composto de lodo de esgoto, classificado como fertilizante orgânico Classe D (MAPA, 2009) é um material rico em nutrientes, especialmente nitrogênio (N) e fósforo (P), e possui elevado conteúdo de matéria orgânica. Contudo, ainda não há relatos na literatura brasileira sobre o uso do composto de lodo de esgoto na cultura da cana-de-açúcar. Assim como, faltam pesquisas para adequar as doses de adubos nitrogenado e fosfatado a serem aplicadas em área agrícola tratada com composto. O objetivo do presente trabalho foi avaliar os efeitos de aplicação e reaplicação de doses de composto de lodo de esgoto e de adubos minerais nitrogenado e fosfatado sobre as propriedades químicas do solo e a produtividade, características tecnológicas e os teores de N e P na folha, caldo e colmo da cana-soca de segundo e terceiro corte. Na aplicação do composto, segunda soca, foram aplicadas quatro doses de composto de lodo de esgoto (0; 27; 54 e 82 t ha-1, base seca), quatro de N (0; 32,3; 64,7 e 98 kg ha-1) e duas de P2O5 (0 e 30 kg ha-1) e na reaplicação, terceira soca, foram aplicadas quatro doses decrescentes do composto (0; 7,8; 15,5 e 23,3 t ha-1, base seca), quatro de N (0; 44,6; 89 e 135 kg ha-1) e duas de P2O5, (0 e 54 kg ha-1) em delineamento em blocos casualizados, em esquema fatorial, com três repetições. Na aplicação do composto, segunda soca, cujo requerimento de N foi considerado como 98 kg ha-1, a produtividade de colmos (TCH) aumentou de 77 a 104 t ha-1 em função das doses do composto. A aplicação do composto pelo critério do nitrogênio promoveu valores de TCH, produtividade de açúcar (TAH), açúcares redutores (AR), açúcar total recuperável (ATR) e açúcares redutores totais (ART) semelhantes aos do tratamento com adubo mineral convencional. Na reaplicação do composto, terceira soca, cujo requerimento de N foi considerado como 135 kg ha-1, a TCH aumentou de 59 a 80 t ha-1 em função das doses do composto. Porém, a maior dose do composto, cuja taxa de mineralização do N foi considerado de 30%, deve ser complementada com 89 kg ha-1 de N mineral para produzir valores de TCH, TAH, AR e ATR semelhantes aos do tratamento com adubo mineral. As doses do composto de lodo de esgoto resultou em incrementos nos teores de N total, C-orgânico, P, pH, Ca, K, soma de bases e capacidade de troca catiônica do solo, em relação ao controle absoluto. Quanto aos teores de N e P nas soqueiras, de modo geral, não houve efeito dos tratamentos, exceto quanto ao teor de N na terceira soca que foi crescente em função das doses de N mineral. Conclui-se, com base no estudo de superfície de resposta, que: 1) a aplicação do composto de lodo de esgoto no cultivo da cana-soca, considerando taxa de mineralização do N de 10% e o requerimento agronômico de N, pode substituir de forma adequada a aplicação dos adubos minerais nitrogenado e fosfatado, e 2) o uso de dose de composto inferior a da dose estabelecida pelo critério do N deve ser proporcionalmente complementada com nitrogênio mineral, seja em condições da primeira e, ou, da segunda aplicação sucessiva / The sewage sludge compost classified as an organic fertilizer Class D (MAPA, 2009) is a material rich in nutrients, especially nitrogen (N) and phosphorus (P), and have high content of organic matter. However, there is a lack of research in the Brazilian literature about the use of the sewage sludge compost on the sugar cane crop. There is also a lack of research to adequate the nitrogen and phosphate fertilizer doses to be applied in agricultural fields treated with compost. The objective of this study was to evaluated effect of levels of sewage sludge compost and mineral sources of nitrogen and phosphorus on the soil chemical proprieties, productivity and technological characteristics and the content of N and P on leaves, juice and stalks of the second and third ratoon cane. On the first application of compost, second ratoon cane, were applied four doses of sewage sludge compost (0; 27; 54 and 81.7 t ha-1, dry base), four of N (0; 32.3; 64.7 and 98 kg ha-1) and two of P2O5 (0 and 30 kg ha-1) and in the reapplication of the compost, third ratoon, the compost was applied in decreased levels 0; 7,8; 15,5 e 23,3 t ha-1, dry base, four of N (0; 44,6; 89 and 135 kg ha-1) and four of P2O5, (0 and 54 kg ha-1) in randomized block design, in factorial design, with three replications. In the first application, second ratoon, which N requirement was considered as 98 kg ha-1, the stalk productivity (TSS) increased from 77 to 104 t ha-1 in function of sewage sludge compost rate. The sewage sludge compost application rate established by nitrogen criteria promoted values of promoted values of stalk productivity (TSS), sugar productivity (TSH), reducing sugars (RS), total recoverable sugars (TRS) and total reducing sugars (TRS) similar to the treatment with mineral fertilizer. In reapplication of compost, whose N request was considered 135 kg ha-1, the TSS increased from 59 to 80 t ha-1 in function of compost application rate and the highest mineralization rate was 30%, should be complemented with 89 kg ha-1 of mineral N to produce values of TSS, TSH, AR, Pol cane, Pol juice and similar to conventional mineral fertilizer. The sewage sludge compost application rate increased N total, organic carbon, P, pH, Ca, K, bases sum and cation exchange capacity soil contents in relation to the control treatment. As for the contents of N and P in the ratoon, in general, there was no effect on the treatments, except for the N content in the third ratoon that increased in function of N fertilizer. Concludes, based on the response surface study that: 1) the application of sewage sludge compost in cultivation of ratoon cane, whereas N mineralization rate of 10% and the agronomic application of N, can replace the adequately the application of nitrogen and phosphorus mineral fertilizer; 2) the use of lower dose of sewage sludge compost established by nitrogen criteria should be proportionally supplemented with mineral nitrogen, either in terms of first and second successive application

Evidências recentes têm demonstrado que dietas com elevado conteúdo de vegetais, frutas e grãos podem reduzir o risco de diversas doenças não transmissíveis. As propriedades benéficas desses alimentos têm sido atribuídas, em grande parte, à presença de substâncias antioxidantes, que são capazes de diminuir os efeitos prejudiciais dos radicais livres. O objetivo deste trabalho foi desenvolver uma formulação de molho tipo Pesto, com base nas propriedades antioxidantes dos seus ingredientes principais: manjericão, castanha do Brasil e azeite de oliva extra virgem. A metodologia foi divida em duas fases: a primeira consistiu na avaliação da interação entre os componentes com atividade antioxidante (AA) presentes nos ingredientes principais do molho, realizada através da metodologia de superfície de resposta por modelagem de misturas. Foi utilizado um planejamento centróide simplex, no qual a resposta medida foi a atividade antioxidante dos extratos de diferentes polaridades obtidos das diferentes formulações. Utilizando-se o método DPPH (1,1-difenil-2-picrilhidrazil) e o sistema ß-caroteno/ácido linoléico, não foi encontrada interação entre os componentes com AA presentes nos ingredientes. Apesar dos modelos obtidos não descreverem adequadamente a variação dos resultados, o manjericão foi identificado como o ingrediente de maior contribuição para a AA total do molho. Foi realizada análise sensorial para determinar a formulação melhor aceita dentre as possibilidades obtidas. A segunda fase consistiu em submeter a formulação determinada na fase 1 às análises de composição centesimal, quantificação dos compostos fenólicos totais e quatro métodos in vitro de avaliação da AA: método do poder redutor, sistema ß-caroteno/ácido linoléico, DPPH e ensaio em meio lipídico pelo aparelho Rancimat®. A formulação final pode ser considerada como uma boa fonte de antioxidantes naturais e portanto fazer parte de uma dieta saudável. / Recent evidences have shown that high consumption of vegetables, fruits and grains can reduce the risk of non-communicable diseases. The healthy properties of these foods have been related mostly to the presence of antioxidants, substances which are known as capable of decreasing the harmful effects of free radicals. The objective of this work was to develop a Pesto sauce formulation, based on the antioxidant properties of its main ingredients: sweet basil, Brazil nut and extra-virgin olive oil. The methodology was divided in two phases: The first one consisted in the evaluation of the interaction between the components with antioxidant activity (AA) present in the sauce\'s main ingredients, applying the response surface methodology with a mixture model. A centroid simplex plan was used, in which the response measured was the AA of the extracts of different polarities from the different formulations. By using the DPPH (1,1-diphenyl-2-picryhydrazyl) method and the ß-carotene/linoleic acid system, no interaction between the components with AA was detected. Although the models could not describe properly the response variation, sweet basil was identified as the main responsible for the total AA of the sauce. Sensory analysis was conducted to determine the most accepted formulation among the possibilities. The second phase consisted in submitting the formulation obtained in phase 1 to centesimal composition analysis, quantification of total phenolics and four in vitro AA methods: reducing power, DPPH method, ß-carotene/linoleic acid system and the Rancimat® method. The final formulation may be considered a good source of natural antioxidants and therefore be part of a healthy diet.

In the European Union the legislation governing fleet CO2 emissions is already in place with a fleet average limit of 130g/km currently being imposed on all vehicle manufacturers. With the target for this legislation falling to 95g/km by 2020 and hefty fines for noncompliance automotive engineers are working a pace to develop new technologies that lower the CO2 emissions and hence fuel consumption of new to market vehicles. As average new vehicle CO2 emissions continue to decline the task of measuring these emissions with high precision becomes increasingly challenging. With the introduction of real world emissions legislation planned for 2017 there is a development driven need to precisely assess the vehicle CO2 emissions on chassis dynamometers over a wide operating range. Furthermore since all type approval and certification testing is completed on chassis dynamometers, any new technology must be proven against these test techniques. Typical technology improvements nowadays require repeatability limits which were unprecedented 5-10 years ago and the challenge now is how to deliver this level of precision. Detailed studies are conducted into the four key areas that cause significant noise to the CO2 emissions results from chassis dynamometer tests. These are the vehicle electrical system, driver behaviour, procedural factors and the chassis dynamometer itself. In each of these areas, the existing contribution of imprecision is quantified, methods are proposed then demonstrated for improving the precision and the improved case is quantified. It was found that the electrical system can be controlled by charging the vehicle battery, not using auxiliary devices and installing current measurement devices on the vehicle. Simply charging the vehicle battery prior to each test was found to cause a change to the CO2 emissions of 2.2% at 95% confidence. Whilst auxiliary devices were found to cause changes to the CO2 emissions of up to 43% for even a relatively basic vehicle. The driver behaviour can be controlled by firstly removing the tolerances from the driver’s aid which it was found improved the precision of the CO2 emissions by 43.5% and secondly by recording the throttle pedal movements to enable the validation of test results. Procedural factors, such as tyre pressures can be easily controlled by resisting the temptation to over check and by installing pressure sensing equipment. Using a modern chassis dynamometer with low parasitic losses will make the job of controlling the dynamometer easier, but all dynamometers can be controlled by following the industry standard quality assurance procedures and implementing statistical process control tools to check the key results. The implementation of statistical process control alone improved the precision of unloaded dynamometer coastdown checks by reducing the coefficient of variation from 6.6 to 4.0%. Using the dynamometer to accelerate the vehicle before coastdown checks was found to approximately halve the variability in coastdown times. It was also demonstrated that verification of the dynamometer inertia simulation and response time are both critically important, as the industry standard coastdown test is insufficient, in isolation, to validate the loading on a vehicle. Six sigma and statistical process control techniques have shown that for complex multiple input single output systems, such as chassis dynamometer fuel economy tests, it is insufficient to improve only one input to the system to achieve a change to the output. As a result, suggested improvements in each noise factor often have to be validated against an input metric rather than the output CO2 emissions. Despite this, the overall level of precision of the CO2 emissions and fuel consumption seen at the start of the research, measured by the coefficient of variation of approximately 2.6%, has been improved by over six times through the simultaneous implementation of the findings from this research with the demonstration of coefficient of variation as low as 0.4%. Through this research three major contributions have been made to the state of the art. Firstly, from the work on driver behaviour an extension is proposed to the Society of Automotive Engineers J2951 drive quality metric standard to include the a newly developed Cumulative Absolute Speed Error metric and to suggest that metrics are reviewed across the duration of a test to identify differences in driving behaviours during a test that do not cause a change to the end of test result. Secondly, the need to instrument the vehicle and test cell to record variability in the key noise factors has been demonstrated. Thirdly, a universal method has been developed and published from this research, to use response modelling techniques for the validation of test repeatability and the correction of CO2 emissions. The impact of these contributions is that the precision of chassis dynamometer emissions tests can be improved by a factor of 6.5 and this is of critical importance as the new real world driving and world light-duty harmonised emissions legislation comes into force over the next two to five years. This legislation will require an unprecedented level of precision for the effective testing of full vehicle system interactions over a larger operating range but within a controlled laboratory environment. If this level of precision is not met then opportunities to reduce vehicle fuel consumption through technology that only has a small improvement on fuel consumption, which is likely given the large advances that have be achieved over the last few decades, will be missed.

Submitted by Eunice Novais (enovais@uepg.br) on 2018-07-24T12:23:29Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Bruno Alexandro Melo Cordoba.pdf: 5568473 bytes, checksum: b7b2a5b911d9cf8f3e1f1564ba6a257e (MD5) / Made available in DSpace on 2018-07-24T12:23:29Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Bruno Alexandro Melo Cordoba.pdf: 5568473 bytes, checksum: b7b2a5b911d9cf8f3e1f1564ba6a257e (MD5) Previous issue date: 2018-01-30 / A moldagem por injeção é um dos processos mais versáteis e amplamente empregada na manufatura de polímeros. Entretanto, há uma incidência de tantos fatores que tendem a influenciar o processo, ao ponto que um controle rigoroso dos parâmetros do processo se faz necessário para obtenção de peças com nível de qualidade adequada. Neste estudo, foram avaliadas as relações entre condições de processo, microestrutura e propriedades para o polímero Acrilonitrila-Butadieno-Estireno (ABS). Para tal, o ABS foi injetado em 9 condições, variando-se importantes parâmetros de injeção: temperatura do fundido (entre 210 e 240 ºC), temperatura do molde (45 – 65 ºC), pressão de compactação (150 - 250 bar) e velocidade de injeção (50 – 110 cm3/s). A partir dos resultados das propriedades mecânicas obtidas (Resistência sob Tração, Resistência ao Impacto, Módulo Elástico e Força Máxima sob Impacto), foram desenvolvidos 3 modelos de predição, determinados via Método Taguchi, Superfície de Resposta e Regressão Linear, sendo que o Método Taguchi apresentou maior eficácia. A partir dos modelos de previsão foram escolhidas 4 condições de injeção distintas da matriz ortogonal, no intuito de se verificar a precisão dos modelos criados. A microestrutura foi avaliada através da Microscopia Eletrônica de Varredura (MEV) de amostras fraturadas por impacto instrumentado e pela medição dos domínios elastoméricos (distribuição do tamanho do Polibutadieno) via análise de imagem. Por fim, foi aplicado o tratamento térmico de alívio de tensões, as propriedades mecânicas foram determinadas e por fim comparadas entre presença e ausência de tratamento térmico, onde foi observado que não se apresentou efeito considerável. / Injection molding is one of the most versatile and widely used processes in the manufacture of polymers. However, there is an incidence of so many factors that tend to influence the process, to the point that strict control of the process parameters is necessary to obtain pieces with adequate quality level. In this study, the relationships between process conditions, microstructure and properties for acrylonitrile-butadiene-styrene (ABS) polymer were evaluated. To do this, ABS was injected under 9 conditions, varying important injection parameters: melt temperature (between 210 and 240 ºC), mold temperature (45-65 ºC), compression pressure (150-250 bar) and injection rate (50-110 cm 3 / s). From the results of the mechanical properties obtained (Resistance under Traction, Impact Resistance, Elastic Modulus and Maximum Force under Impact), 3 prediction models were developed, determined by the Taguchi Method, Response Surface and Linear Regression, with the Taguchi Method was more effective. From the prediction models four different injection conditions of the orthogonal matrix were chosen, in order to verify the accuracy of the models created. The microstructure was evaluated by Scanning Electron Microscopy (SEM) of fractured samples by instrumented impact and by the measurement of the elastomeric domains (distribution of the polybutadiene size) through image analysis. Finally, the thermal treatment of stress relief was applied, the mechanical properties were determined and finally compared between the presence and absence of heat treatment, where it was observed that no considerable effect was observed.

L'objectif de cette thèse est l'investigation de nouvelles méthodes de surface de réponse afin de réaliser l'analyse de sensibilité de modèles numériques complexes et coûteux en temps de calcul. Pour ce faire, nous nous sommes intéressés aux méthodes basées sur la décomposition ANOVA. Nous avons proposé l'utilisation d'une méthode basée sur les splines de lissage de type ANOVA, alliant procédures d'estimation et de sélection de variables. L'étape de sélection de variable peut devenir très coûteuse en temps de calcul, particulièrement dans le cas d'un grand nombre de paramètre d'entrée. Pour cela nous avons développé un algorithme de seuillage itératif dont l'originalité réside dans sa simplicité d'implémentation et son efficacité. Nous avons ensuite proposé une méthode directe pour estimer les indices de sensibilité. En s'inspirant de cette méthode de surface de réponse, nous avons développé par la suite une méthode adaptée à l'approximation de modèles très irréguliers et discontinus, qui utilise une base d'ondelettes. Ce type de méthode a pour propriété une approche multi-résolution permettant ainsi une meilleure approximation des fonctions à forte irrégularité ou ayant des discontinuités. Enfin, nous nous sommes penchés sur le cas où les sorties du simulateur sont des séries temporelles. Pour ce faire, nous avons développé une méthodologie alliant la méthode de surface de réponse à base de spline de lissage avec une décomposition en ondelettes. Afin d'apprécier l'efficacité des méthodes proposées, des résultats sur des fonctions analytiques ainsi que sur des cas d'ingénierie de réservoir sont présentées. / The purpose of this thesis is to investigate innovative response surface methods to address the problem of sensitivity analysis of complex and computationally demanding computer codes. To this end, we have focused our research work on methods based on ANOVA decomposition. We proposed to use a smoothing spline nonparametric regression method, which is an ANOVA based method that is performed using an iterative algorithm, combining an estimation procedure and a variable selection procedure. The latter can become computationally demanding when dealing with high dimensional problems. To deal with this, we developed a new iterative shrinkage algorithm, which is conceptually simple and efficient. Using the fact that this method is an ANOVA based method, it allows us to introduce a new method for computing sensitivity indices. Inspiring by this response surface method, we developed a new method to approximate the model for which the response involves more complex outputs. This method is based on a multiresolution analysis with wavelet decompositions, which is well known to produce very good approximations on highly nonlinear or discontinuous models. Finally we considered the problem of approximating the computer code when the outputs are times series. We proposed an original method for performing this task, combining the smoothing spline response surface method and wavelet decomposition. To assess the efficiency of the developed methods, numerical experiments on analytical functions and reservoir engineering test cases are presented.