The theoretical stress-strain behaviour of individual fibre reinforced cement composites is reviewed. Based on the multiple cracking concept of the existing theory, analytical expressions are developed to describe the tensile stress-strain behaviour of a fibre-cement hybrid composite consisting of three components, i.e. two reinforcing fibres with different moduli, strengths and strains to failure and a common cement binder. The model predicts that the tensile stress-strain curve of the hybrid composites consists of five stages, instead of three stages of the existing models for individual fibre cements, and relates the tensile behaviour of each stage to the component properties of the components and the test system parameters. A description is given of the physical and mechanical properties of four types of reinforcing fibres used in the study. These were fibrillated polypropylene film, alkali-resistant glass, polyvinyl alcohol fibres and carbon fibres. A small number of direct tensile tests on continuous glass, carbon and polyvinyl alcohol were performed. The tensile stress-strain behaviour of four types of fibre-cement hybrid composites was studied with particular emphasis on that of the glass- polypropylene hybrids for which the flexural load-deflection behaviour was also examined. It is shown that the fibre-cement hybrid composites yield superior engineering properties over their parent composites and the improvements are sensitive to volume fractions of each of the two fibres. The measured tensile stress-strain curves of the hybrids were compared with the theoretical predictions and satisfactory agreement in general is obtained. Implications from the present work for the design of fibre-cement hybrid composites are assessed.

No description available.

No description available.

Machine learning is a branch of artificial intelligence that uses data to automatically build inferences and models designed to generalise and make predictions. In this thesis, the use of machine learning in materials science is explored, for two different problems: the optimisation of gallium nitride optoelectronic devices, and the prediction of material failure in the setting of laboratory earthquakes. Light emitting diodes based on III-nitrides quantum wells have become ubiquitous as a light source, owing to their direct band-gap that covers UV, visible and infra-red light, and their very high quantum efficiency. This efficiency originates from most electronic transitions across the band-gap leading to the emission of a photon. At high currents however this efficiency sharply drops. In chapters 3 and 4 simulations are shown to provide an explanation for experimental results, shedding a new light on this drop of efficiency. Chapter 3 provides a simple and yet accurate model that explains the experimentally observed beneficial effect that silicon doping has on light emitting diodes. Chapter 4 provides a model for the experimentally observed detrimental effect that certain V-shaped defects have on light emitting diodes. These results pave the way for the association of simulations to detailed multi-microscopy. In the following chapters 5 to 7, it is shown that machine learning can leverage the use of device simulations, by replacing in a targeted and efficient way the very labour intensive tasks of making sure the numerical parameters of the simulations lead to convergence, and that the physical parameters reproduce experimental results. It is then shown that machine learning coupled with simulations can find optimal light emitting diodes structures, that have a greatly enhanced theoretical efficiency. These results demonstrate the power of machine learning for leveraging and automatising the exploration of device structures in simulations. Material failure is a very broad problem encountered in a variety of fields, ranging from engineering to Earth sciences. The phenomenon stems from complex and multi-scale physics, and failure experiments can provide a wealth of data that can be exploited by machine learning. In chapter 8 it is shown that by recording the acoustic waves emitted during the failure of a laboratory fault, an accurate predictive model can be built. The machine learning algorithm that is used retains the link with the physics of the experiment, and a new signal is thus discovered in the sound emitted by the fault. This new signal announces an upcoming laboratory earthquake, and is a signature of the stress state of the material. These results show that machine learning can help discover new signals in experiments where the amount of data is very large, and demonstrate a new method for the prediction of material failure.

This dissertation concerns failure modelling with material imperfections and element erosion in finite element analyses. The aim has been to improve the element erosion technique, which is simple to use and implement and also computationally inexpensive. The first part of the dissertation serves as an introduction to the topic and as a summary of the methodologies presented in the following part. The second part consists of seven appended papers. In paper A the standard element erosion technique is used for projectile penetration. In papers B and C a methodology that accounts for size effects is developed and applied to crack initiation in armour steel and tungsten carbide. A methodology to better predict the stress state at crack tips with coarse meshes is presented and applied to armour steel in paper D. Papers E and F concern the development of selective mass scaling which allows for larger time steps in explicit methods. Finally, in paper G the previously presented methodologies are used in combination and validated against experimental results on tungsten carbide. The computations show good agreement with the experimental results on failure initiation for both materials, while the computational results on the propagation of cracks show better agreement for the armour steel than for the tungsten carbide. / On the day of the public defence of the doctoral thesis, the status of articles I, III and IV was Accepted and article VII was Submitted.

La fracture des matériaux, omniprésente aussi bien en science des matériaux qu’en géologie, implique souvent des événements soudains et imprévisibles, sans précurseurs détectables macroscopiquement. Une compréhension approfondie des mécanismes microscopiques conduisant in fine à la rupture est requise, mais les expériences restent rares. La détection de la dynamique microscopique dans les échantillons cisaillés est expérimentalement très difficile, car elle nécessite de combiner sensibilité mécanique, qualité optique et exigences strictes sur l’encombrement. Dans ce travail, nous présentons l'une des premières tentatives réussies de mesure des précurseurs microscopiques de fracture dans des matériaux mous modèles, grâce à des mesures de la plasticité microscopique à l'aide d'un nouvel instrument, couplant une cellule de cisaillement à contrainte contrôlée à un appareil de diffusion de lumière statique et dynamique (DLS) à petits angles. Dans un premier temps, nous montrons théoriquement, numériquement et expérimentalement comment la DLS, une technique très puissante difficile à utiliser pour un échantillon sous cisaillement, peut être utilisée comme outil de mesure de la dynamique microscopique dans les systèmes mous sous cisaillement. Pour un solide parfait et un fluide visqueux simple, le champ de déplacement résultant d'une déformation de cisaillement est purement affine. Nous montrons comment les déplacements affines et non affines, qui sont présents dans de nombreuses situations d’intérêt (matériaux élastiquement hétérogènes ou en raison de réarrangements plastiques) peuvent être évalués séparément par DLS et discutons de l'effet des non-idéalités dans des expériences typiques.Ce travail est centré sur un gel colloïdal fractal modèle, dont nous caractérisons la rhéologie linéaire en loi de puissance. Nous montrons que celle-ci est décrite par un modèle phénoménologique Fractional Maxwell (FMM), et discutons la relation possible entre FMM et la structure microscopique du gel.Sous une contrainte de cisaillement constante (expérience de fluage), le gel colloïdal présente une déformation rapide élastique suivie d'un fluage lent en loi de puissance, puis, après plusieurs heures par une accélération du taux de cisaillement, entraînant la rupture retardée du gel. Nos expériences montrent que le premier régime en loi de puissance, bien décrit par la viscoélasticité linéaire, correspond à l'échelle microscopique à une dynamique partiellement nonaffine, mais entièrement réversible. Lorsque la viscoélasticité dévie de la linéarité, une accélération nette, localisée dans le temps de la dynamique non-affine, est observée. Ces réarrangements rapides précèdent la fracture macroscopique du gel de plusieurs heures: ce sont des précurseurs dynamiques de la fracture qui permettent de prédire l’évolution du gel bien avant toute mesure rhéologique.Pour obtenir une image plus complète de la fracture, nous étudions l'apparition de l'irréversibilité lors d’une perturbation cyclique répétée plusieurs fois (expérience de fatigue). En suivant l'évolution stroboscopique du système en fonction de la déformation cumulée, on constate que, au-delà du régime linéaire, le taux de relaxation augmente brusquement, signature de plasticité. Si la contrainte appliquée est suffisamment grande, le gel à long terme montre une rupture retardée, en analogie avec celle observée en fluage. Les différences et similitudes entre les deux mécanismes de fracture sont discutées.Enfin, la généralité des résultats obtenus sur les gels colloïdaux est vérifiée en étudiant comme second système modèle un verre colloïdal, dont la mise en écoulement sous contrainte oscillante est un processus progressif, pour lequel deux modes de relaxation contribuent à la dynamique observée. Les analogies qualitatives trouvées avec des systèmes similaires (par ex. des émulsions concentrées) suggèrent qu'une image unifiée pourrait être obtenue, motivant des recherches futures. / Material failure is ubiquitous, with implications from geology to everyday life and material science. It often involves sudden, unpredictable events, with little or no macroscopically detectable precursors. A deeper understanding of the microscopic mechanisms eventually leading to failure is clearly required, but experiments remain scarce. The detection of microscopic dynamics in samples under shear is experimentally very challenging, because it requires to combine the highest mechanical sensitivity to strict requirements on the geometry of the whole setup and on the quality of the optical interfaces. In this work we present one of the first successful attempts to measure microscopic failure precursors in model soft solids. Here, microscopic plasticity under shear is observed using a novel setup, coupling a custom-made stress controlled shear cell to small angle static and dynamic light scattering (DLS).DLS is a very powerful technique, but its application to materials under shear is not trivial. In a first step we show a theoretical, numerical and experimental investigation of how DLS may be used as a tool to measure the microscopic dynamics in soft systems under shear. In ideal solids and simple viscous fluids, the displacement field resulting from an applied shear deformation is purely affine. Additional non-affine displacements arise in many situations of great interest, for example in elastically heterogeneous materials or due to plastic rearrangements. We show how affine and non-affine displacements can be separately resolved by DLS, and discuss the effect of several non-idealities in typical experiments.As a model system, this work mainly focuses on a fractal colloidal gel. We thoroughly characterize the linear power-law rheology of the gel, we show that it is very accurately described by the phenomenological Fractional Maxwell (FM) model, and we discuss the possible relationship between the FM model and the microscopic structure of the gel.Under a constant shear stress (creep experiment), the colloidal gel exhibits a fast, elastic deformation followed by a slow sublinear power-law creep, which is eventually interrupted after several hours by an upturn in the shear rate, leading to the delayed failure of the material. Our experiments show that the first power-law regime, nicely described by linear viscoelasticity, corresponds at the microscopic scale to partially nonaffine, yet fully reversible dynamics. Upon deviation from the linear viscoelasticity, a sharp acceleration, localized in time of the nonaffine dynamics is observed. These faster rearrangements precede the macroscopic failure of the gel by thousands of seconds: they thus are dynamic precursors of failure that allow one to predict the fate of the gel well before any rheological measurement.To obtain a more comprehensive picture of material failure, we next address the onset of irreversibility under a cyclic perturbation repeated many times (fatigue experiment). By following the stroboscopic evolution of the system as a function of the cumulated deformation, we observe that as soon as the shear amplitude is increased beyond the linear regime the relaxation rate increases abruptly, indicating that irreversible plasticity is at play. If a large enough stress amplitude is applied, the system on the long run displays delayed fatigue failure, with reminiscences of the one observed in creep. Differences and similarities between the two failure mechanisms are discussed.Finally, the generality of the results obtained on colloidal gels is checked by investigating as second model system a soft colloidal glass. In this case, our experiments indicate that oscillatory yielding is a gradual process, where two relaxation modes contribute to the observed dynamics. Qualitative analogies found with similar systems (e.g. concentrated emulsions) suggest that a general picture might be obtained with our study, which motivates ongoing and future investigations.

This study focuses on the improvement of the axial buckling capacity of elliptical composite cylinders through the use of a circumferentially-varying lamination sequence. The concept of varying the lamination sequence around the circumference is considered as a viable approach for off-setting the disadvantages of having the cylinder radius of curvature vary with circumferential position, the source of the reduced buckling capacity when compared to a circular cylinder with the same circumference. Post-buckling collapse behavior and material failure characteristics are also of interest. Two approaches to implementing a circumferential variation of lamination are examined. For the first approach the lamination sequence is varied in a stepwise fashion around the circumference. Specifically, each quadrant of the cylinder circumference is divided into three equal-length regions denoted as the crown, middle, and side regions. Eight different cylinders designs, whereby each region is constructed of either a quasi-isotropic or an axially-stiff laminate of equal thickness, are studied. Results are compared to the baseline case of an elliptical cylinder constructed entirely of a quasi-isotropic laminate. Since the thickness of the quasi-isotropic and axially-stiff laminates are the same, all cylinders weight the same and thus comparisons are meaningful. Improvements upwards of 18% in axial buckling capacity can be achieved with one particular stepwise design. The second approach considers laminations that vary circumferentially in a continuous fashion to mitigate the effects of the continuously-varying radius of curvature. The methodology for determining how to tailor the lamination sequence circumferentially is based on the analytical predictions of a simple buckling analysis for simply-supported circular cylinders. With this approach, axial buckling load improvements upwards of 30% are realized. Of all the cylinders considered, very few do not exhibit material failure upon collapse in the post-buckled state. Of those that do not, there is little, if any, improvement in bucking capacity. Results for the pre-buckling, buckling, post-buckling, and material failure are obtained from the finite-element code ABAQUS using both static and dynamic analyses. Studies with the code demonstrate that the results obtained are converged. / Ph. D.

En ingénierie mécanique, la rupture des matériaux est un risque qu'il convient d'anticiper et qui reste aujourd'hui une menace pour les structures. La rupture des systèmes pré-fissurés a lieu quand l'énergie libérée par la propagation de la fissure préexistante excède un seuil critique (taux de restitution d'énergie) qui représente une propriété du matériau. Au contraire, la rupture de systèmes sans défauts préexistants survient lorsque la contrainte appliquée atteint la résistance, également propriété du matériau. L'existence de deux critères pour la rupture semble indiquer des mécanismes d'amorçage différents, ce qui soulève la question des cas réels intermédiaires qui présentent des concentrations de contrainte modérées. Différentes approches existantes sont cohérentes avec les deux situations limites mais il n'y a pas de consensus clair dans la communauté scientifique. Dans cette thèse, nous étudions les mécanismes de la rupture fragile à l'échelle atomique afin d'en comprendre l'origine physique pour différentes concentrations de contraintes. La rupture provient de la rupture des liaisons à l'échelle atomique. Nous utilisons donc des techniques de simulation moléculaire pour étudier la physique élémentaire de l'initiation de la rupture fragile. Dans ce but, on étudie deux types de structure atomique. Le premier est un matériau modèle à maille triangulaire, dont le potentiel permet d'interpréter analytiquement, et avec précision, les résultats des simulations moléculaires. L'étude est étendue à un système plus réel : le graphène. Ce matériau, qui présente une résistance élevée au regard de sa faible ténacité, a l'une des plus petites tailles de zone d'élaboration par rapport aux autres matériaux fragiles, ce qui permet d'appliquer numériquement les concepts de la rupture fragile jusqu'à l'échelle nanométrique de la simulation moléculaire. On s'intéresse dans un premier temps à la rupture des matériaux à 0K. À cette température, un système atomique est en équilibre statique. La rupture peut donc être traitée comme une instabilité. L'analyse du profil énergétique du système atomique fournit un moyen d'identifier les mécanismes de rupture. Nous montrons qu'on peut identifier la rupture en cherchant les valeurs propres nulles ou négative de la matrice hessienne. Les vecteurs propres correspondants indiquent les modes de rupture et montrent l'apparition de bandes de transition entre mouvements de groupes d'atomes pour des systèmes intacts, dont la largeur rappelle la longueur d'élaboration, généralement introduite dans des théories macroscopiques d'initiation de la rupture. On étudie aussi l'effet de la présence de défauts sur les modes d'instabilité et leur dégénérescence. Cette étude fournit une technique générale pour identifier les mécanismes d'initiation de rupture quelle que soit la concentration de contrainte dans la structure. On s'intéresse ensuite aux températures non nulles. On étudie les effets combinés de la température, de la taille du système et du taux de chargement. En partant de la théorie cinétique, nous montrons qu'il existe des lois d'échelle générales fournissant une équivalence taille-vitesse de chargement-température et permettant de relier résistance et ténacité à la limite à 0K. La différence entre la loi d'échelle en résistance et celle en ténacité réside dans le fait que la rupture ne soit pas sensible à la taille du système pré-fissuré mais au nombre de pointes de fissure. Cela indique une différence statistique essentielle entre la rupture en résistance et la fracture ce qui permet de mieux comprendre la transition de l'une à l'autre. Dans l'esprit de mieux comprendre la transition entre les deux types de rupture, on traite le cas de trous elliptiques à différents rapports d'aspects et on analyse en même temps l'effet de cette transition sur les modes d'instabilité. On étudie en dernière partie, l'effet des surfaces libres et les différents paramètres caractérisant cette situation / In mechanical engineering, failure is a risk that must be anticipated and is still a threat for structures. The failure of pre-cracked systems occurs when the energy released by the propagation of the pre-existing crack exceeds a critical threshold (Griffith's energy release rate) which represents a property of the material. On the contrary, the failure of systems without pre-existing defects occurs when the applied stress reaches the strength, also property of the material. The existence of two criteria for failure suggests different driving mechanisms, which raises the question of intermediate cases with moderate stress concentrations. Different existing approaches are consistent with the two limit cases but there is no clear consensus in the scientific community.In this work, we study the mechanisms of brittle failure on the atomic scale in order to understand the underlying physical mechanisms. Macroscopic failure comes from the breaking of bonds at the atomic scale. We therefore use molecular simulation techniques to study the elementary physics of brittle failure initiation. Two types of atomic structure are studied. The first one is a triangular lattice toy model whose simplicity allows precise analytical interpretation of the molecular simulation results. The study is extended to a more realistic system: graphene. This material, which has a high strength and a rather low toughness in comparison, has one of the smallest process zones compared to other brittle materials, which makes it possible to apply the concepts of brittle failure up to the nanometric scale of molecular simulation. We first investigate the failure of materials at 0K. At this temperature, an atomic system is in static equilibrium. The breaking of bonds can be treated as instability. The analysis of the energy profile of the atomic system provides a means of identifying the mechanisms of failure. We show that we can identify failure initiation by looking for negative or zero eigenvalues of the Hessian matrix. The corresponding eigenvectors indicate the modes of failure and show the appearance of transition bands between motions of groups of atoms for intact systems, whose width recalls the size of the process zone, generally introduced in macroscopic theories of failure initiation. We also study the effect of defects on the instability modes and their degeneracy. This study provides a general technique to capture fracture initiation mechanisms irrespective of the stress concentration in the structure. We focus afterwards on finite temperatures. We study the combined effects of temperature, system size and loading rate. Starting from the kinetic theory, we identify general scaling laws providing a size-loading rate-temperature equivalence and relating the strength and toughness to the limit at 0K. The difference between the scaling law of strength and that of toughness lies in the fact that failure is not sensitive to the size of the pre-cracked system but to the number of crack tips. This indicates an essential statistical difference between strength and fracture failures which makes it possible to better understand the transition from one to the other.In order to better understand the transition between the two types of failure, we treat the case of elliptic holes with different aspect ratios and we focus at the same time on the effect of this transition on instability modes. We study in the last part the case of non-periodic structures with free surfaces. We determine the various parameters characterizing this situation and the effect of the presence of surface phenomena on instability modes

In the automobile industry, there is a big push for the automotive car manufacturers to base engineering decisions on the results of Computer Aided Engineering (CAE) solutions, and to transform the prototyping and testing, from a costly iterative process to a final verification and validation step. The variability in components material properties and environmental conditions together with the lack of knowledge about the underlying physics of complex systems often make it impractical to make reliable predictions based on only deterministic CAE models. One such area is the CAE modelling of cast aluminium components. These cast aluminium components have gained a huge relevance in the automobile industries due to their commendable mechanical properties. The advantage of the cast aluminium alloys are being a well-established alloy system in manufacturing processes, their functional integrity and relatively low weight. However, the presence of pores and micro-voids obtained during the manufacturing process constitutes a specific material behaviour and establishes a challenge in modelling of the cast materials. Furthermore, the low ductility of the materialdemands for the advanced numerical model to predict the failure. The main focus of this master thesis work is to investigate modelling technique of a cast aluminium alloy component, a spring tower, for a drop tower test and validate the predicted behaviour with the physical test results. Volvo Car Corporation currently uses a material model provided by MATFEM for cast aluminium parts which are explored in this thesis work, to validate the material model for component level testing. The methodology used to achieve this objective was to develop a boundary condition to perform component level tests in the drop tower and to correlate these with the obtained results found by using various modelling techniques in the explicit solver LS-DYNA. Therefore, precise and realistic modelling of the drop tower is crucial because the simulation results can be influenced by major design changes. A detailed finite element model for the spring tower has been developed from the observations made during the physical testing. The refined model showed good agreement with the existing model for the spring tower and observations from physical tests.

In this thesis the position of parties under a fixed-term agreement under section 14 of the Consumer Protection Act 68 of 2008 is analysed critically. The purpose of this thesis is first to establish whether parties to a fixed-term agreement are better protected in terms of section 14 of the CPA when the consumer needs to terminate the contract based on the material failure to perform by the supplier, than under the common law. Second, this thesis explores whether the maximum duration of fixed-term agreements should be limited by statute. Various aspects affecting parties to these agreements, for instance the freedom to contract, pacta servanda sunt, and standard-form agreements, are considered. The South African position is then compared to the position in Singapore under the Consumer Protection (Fair Trading) Act, and to the United Kingdom under the Consumer Rights Act, to gain perspective and objectively evaluate the provisions of section 14 of the Consumer Protection Act 68 of 2008 to establish whether South Africa can benefit from lessons learnt from these jurisdictions. Finally, principle-based amendments to the provisions of the CPA are recommended to improve the position of the consumer under fixed-term agreements to effect best practice solutions and ensure adherence to the aims and purposes of the Consumer Protection Act 68 of 2008 and international guidelines. This thesis is based on the law as at 18 June 2020, found in sources available in South Africa, and Singaporean law available in the database of the National University of Singapore. / Hierdie proefskrif is ’n kritiese analise van die posisie van partye tot vastetermynkontrakte ingevolge artikel 14 van die Suid-Afrikaanse verbruikersbeskermingswetgewing, die Consumer Protection Act 68 van 2008 (CPA). Die doel van die analise is eerstens om vas te stel of partye tot ’n vastetermynkontrak ingevolge artikel 14 van die CPA beter beskerming geniet ingevolge die CPA wanneer die verbruiker die vastetermynkontrak moet beëindig weens die wesenlike wanprestasie deur die verskaffer, as ingevolge die gemenereg. Tweedens ondersoek die proefskrif of dit wenslik is dat die maksimum duur van vastetermynkontrakte deur wetgewing beperk word. Verskeie aspekte wat die posisie van partye tot vastetermynkontrakte beïnvloed word ondersoek, onder andere kontrakteervryheid, die leerstuk pacta servanda sunt en standaardkontrakte. Die Suid-Afrikaanse posisie word dan vergelyk met dié in Singapoer, ingevolge die Consumer Protection (Fair Trading) Act (CPFTA), en die Verenigde Koninkryk, ingevolge die Consumer Rights Act (CRA) om perspektief te kry op die studie, en ten einde die bepalings van artikel 14 objektief te oorweeg om vas te stel of Suid-Afrika kan kersopsteek by hierdie jurisdiksies. Laastens word voorstelle gemaak om die posisie van die verbruiker tot vastetermynkontrakte ingevolge die CPA te verbeter om beste gebruikspraktyke te implementeer, en te verseker dat die doelwitte van die CPA en internasionale verbruikersriglyne bereik word. Hierdie studie weerspieël die regsposisie soos op 18 Junie 2020 in bronne wat plaaslik beskikbaar is, asook in bronne aan my beskikbaar gestel deur die Nasionale Universiteit van Singapoer tydens ’n navorsingsbesoek daar. / Kule thesisi isimo sezinhlangano ezingaphansi kwesivumelwano sesikhathi esinqunyiwe, ngaphansi kwesigaba 14 koMthetho 68 ka 2008, uMthetho weZokuvikelwa koMthengi uhlaziywa ngendlela egxekayo. Inhloso yalolu cwaningo ukusungula ukuthi mhlawumbe lezi zinhlangano ezingaphansi kwesivumelwano sesikhathi esinqunyiwe sivikeleke kangcono ngaphansi kwesigaba 14 se-CPA uma kunesidingo sabathengi sokuqedwa kwesivumelwano esencike phezu kokwehluleka ukwenza umsebenzi waloyo ongumthumeli wempahla, okwehlukile emthethweni owejwayelekile. Okwesibili, le thesis iphenya ukuthi mhlawumbe isikhathi isikhathi esinde sesivumelwano sesikhathi esinqunyiwe kufanele sincishiswe ngokomthetho oshayiwe. Izinto ezahlukahlukene ezithinta lezi zivumelwano, njengesibonelo, inkululeko yokungena esivumelwaneni pacta servanda sunt, kanye nesivumelwano ezingaguquki, kuyizinto ezibhekwayo. Isimo seNingizimu Afrika siqhathaniswa nesimo sezwe laseSingapore ngaphansi koMthetho wezokuVikelwa kwabaThengi (Fair Trading), kanye nasezweni laseUnited Kingdom ngaphansi koMthetho owaMalungelo abaThengi, ukuthola umqondo kanye nokuhlola izimiso ngaphansi kwesigaba 14 soMthetho 68 ka 2008, uMthetho oVikela abaThengi ukuthola ukuthi ngabe iNingizimu Afrika kukhona ekuzuzile kwizifundo ezifundwe kulezi zakhiwo zemithetho. Okokugcina, izichibiyelo ezisuselwe kwimigomo mayelana nalokho okushiwo yi-CPA inconywe ukuthi yenze ngcono isimo sezinhlangano ezingaphansi kwezivumelwano zesikhathi esinqunyiwe ukuletha izisombululo ezingcono kanye nokuqinisekisa ukuthi kulandelwa izinhloso kanye nemisebenzi yoMthetho 68 ka 2008, okunguMthetho oVikela abaThengi kanye nemihlahlandlela yezizwe zomhlaba. Lolu cwaningo lususelwe phezu komthetho kusukela mhla zi 18 uNhlangulana 2020, luyatholakala emithonjeni yaseNingizimu Afrika, kanye nomthetho waseSingapore uyatholakala emthonjeni yedatha yaseNational University of Singapore. / Mercantile Law / LL. D.