Thermal Wave Imaging (United States)

Abstract As of today, hydrogen can play a significant role in decarbonizing the world’s energy supply to mitigate climate change and can be transported via pipeline. Hence, it is becoming more and more important in many companies’ strategies to build a clean-energy business, exploring ways of transporting hydrogen as a gas replacement for natural gas or as an addition in blended configuration using existing pipeline networks, or new designed pipelines fit for full hydrogen transport. However, for steel pipelines, it is well recognized that hydrogen presents some peculiarities to be considered during pipeline system design as may promote hydrogen embrittlement phenomena which potentially could have an adverse effect on the pipeline integrity properties such as ductility, fracture toughness and fatigue performance. Fatigue is considered a major failure mode for Offshore pipeline girth welds where the longitudinal stresses can be as high as the actual yield of the line (sometimes even more) and subject to fluctuations that are significant during lifetime. Same conclusions can be observed for longitudinal flaws in the seam weld/base material in case the trunkline is used as a hydrogen storage tank. In that case high stress cycles contribute to a consistent fatigue crack growth with respect to natural gas scenario where the pressure and temperature fluctuations induce low stress cycles which have negligible effect on fatigue growth. The combination of embrittlement with the severe loads occurring to an offshore pipeline calls for a comprehensive awareness of material performance under such conditions. To achieve that, the first step has been the classification of failure modes by type of installation condition and selection of the tests required to characterize materials against them. Consequently, Saipem, as pipeline construction contractor, funded a test campaign to start filling the gap. The purpose of the testing campaign is to assess the behavior of base material, seam weld and Girth Welds under different hydrogen environments, to establish the limiting criteria for their resistance to H2 embrittlement, to contribute to the reduction of any over-conservatism in ASME B31.12 and bring solutions for the development of an achievable and affordable hydrogen pipeline network. This paper provides the experimental results in terms of fatigue endurance (S-N curves) and fatigue crack growth (FCGR curves) properties of testing performed in hydrogen environment at pressure of 200bar. Tests were also performed in air to compare the influence of hydrogen gas on the fatigue life of Saipem offshore girth welds. Additionally, a comparison of fatigue properties in severe H2S environment was conducted. The conclusions and the next steps of the campaign will be summarized in the paper, written for the sake of sharing knowledge and experience for a faster and efficient transition toward a sustainable and safe economy in offshore hydrogen transportation systems.

The theme of E-Mobility covers many forms of electrified transportation. Electric motors are powered by rechargeable battery systems (e.g. electric cars or bicycles) or power taken directly from a grid supply (e.g. trains or trams). In all cases the purpose of the electrified system is to provide some form of mobility for humans or a payload with zero exhaust pipe emissions and lower carbon footprint of service. The proliferation of E-Mobility solutions marks a significant step towards Net Zero targets.

Abstract Recently the old accommodation platform (OAP) was decommissioned in Offshore Abu Dhabi. This platform was founded on four legs with piles inside and duly grouted inside pile and annulus. The main objective of this to carry out bond strength tests and finite element (FE) analysis for retrieved OAP grouted samples to investigate if any ageing effect on the bond strength of the grouted pile/sleeve connections for aged offshore structures. Nine Sleeve/Pile samples of varying lengths from 240mm to 1200mm were extracted for testing from the decommissioned platform. Dimensional analysis was carried out to assess the thickness loss and eccentricity. A bespoke testing rig with the maximum load capacity of 15,000kN was built at TWI Ltd. to perform bond strength tests. Finite element (FE) simulation of the testing was carried out and compared to the test results to calibrate and fine-tune material constitutive behaviour parameters and interfacial (friction and bond) parameters. Specimen measurements revealed a significant scatter in annulus grout thicknesses of various sleeve/pile specimens with maximum variations of up to 52%. These results indicate that pile alignment is strongly variable. Shear keys in the form of steel rings welded alternately onto the leg's inner surface and the pile outer surface providing mechanical resistance to relative sliding of the grout between the two bodies. The testing results shown that the ultimate loads varied significantly among various specimens, ranged between 9920kN for 1m specimen and 1800kN for 1.2m specimen. FE simulations agreed well with the observed failure modes and were used to investigate how the measured failure loads were influenced by grout material properties, cohesive bond behaviour and geometrical parameters such as shear keys and eccentricity. From the FE studies, it was found that different cohesive (surface) parameters are required to give the best fit, with the higher cohesive stiffness and strength associated with a higher failure load. Grout strength is also a significant parameter, but the effect of surface cohesion is less significant compared to material strength. The majority of the tested values were found to be meeting the minimum bond strength resulting from available standards (eg. ISO 19902). This type of real time testing output will provide insight into various parameters that contribute to bond strength in pile leg grouted connections. Moreover, these test and assessment results will form an integral and important input to various ongoing researches associated with ADNOC's grouted connections being carried out as part of another JIP led by National University of Singapore which is aimed at deriving design equations applicable to grouted connections beyond codal limits.

Global illumination refers to a complete shading model that simulates real lighting and reflection as accurately as possible. Whether used for product prototyping or special effects for entertainment, the goal is to match the appearance of the real world. The origins of global illumination come at the intersection of a steady progression of shading models with the ancient simulation technique of ray tracing.

Abstract Scope Advanced Non Destructive Testing (NDT) techniques rely on consistent acquisition of data and its reliable analysis. As technology advances, new challenges emerge. For instance, the amount of data produced is exceeding the qualified personnel available for data analysis; moreover, the files produced can be easily handle unethically. Our project proposes the implementation of Artificial Intelligence (AI) techniques to develop algorithms to better harness the data available, in order to enhance the quality of data analysis and better monitor ethical practices. Method: For any NDT technique, the consistency of the results and the reliability of the findings depends heavily on the personnel performing the inspections and evaluating the results. As more advanced NDT techniques are available in the areas of ultrasound, digital data becomes available opening the door for intelligent tools for analysing and handling ultrasound data. This project proposes an innovative analysis software based on Computational Intelligence (CI) techniques. The implementation of this software reduces the time needed for a single analysis and the consistency of results, more importantly; it can be use as an audit tool to ensure data files have not been mishandle. Results/conclusions For the first stage of the proposed CI cloud-based software, the data collected by the inspector is send via internet connection to web-based servers. During the second stage, the data will be verify for quality; if any data is missing or poor-quality is detected, the software will inform the inspector that data must be resubmitted. Once the verification of data is completed, the data analysis is then perform by CI-based algorithms, which can recognise and classify features within the data such as geometry indications, anomalies and defects. Following the CI-based analysis, the software generates a complete report and the results are be available to the user via a 3D visualization interface. This report includes details of sizing, characterisation, location of defects, geometry indications and other relevant information related to the analysed data. The information contained in the interface and generated by the software will be available to the final user for validation and approval. The CI-based analysis tools have already been use to monitor several data files from NDT inspections using Phased Array Ultrasound (PAUT) and the results have successfully verify the authenticity of the ultrasound raw data, which is a critical verification step and evidence of any mal practices or mistakes of data handling. Novelty There is a lack of reliable tools available to NDT experts that can facilitate the task of analysing data; this innovative software takes advantage of the CI techniques and expert knowledge to address this issue. Furthermore, our approach offers a high degree of consistency for identifying defects; improves the quality of the analysis and reduces the time invested in such critical NDT duty. Auditing raw data from ultrasound inspection is a challenging task; by taking advantage of CI-based analysis tools this task can be easily implement it as reliable auditing practice.

The ionic nature of a functionalized protic ionic liquid cannot be rationalized simply through the differences in aqueous proton dissociation constants between the acid precursor and the conjugate acid of the base precursor. The extent of proton transfer, i.e. the equilibrium ionicity, of a tertiary ammonium acetate protic ionic liquid can be significantly increased by introducing an hydroxyl functional group on the cation, compared to the alkyl or amino-functionalized analogues. This increase in apparent ionic nature correlates well with variations in solvent-solute and solvent-solvent interaction parameters, as well as with physicochemical properties such as viscosity.

Laser beam melting of titanium alloy Ti-6Al-4V was performed with an Yb-fibre laser to produce weld pools under a range of conditions. These included the use of a flux covering of molten CaF2 or a molten mixture of CaF2 and NaF, in an atmosphere of ambient air, either with or without the application of cathodic protection to the Ti-6Al-4V. As anticipated, in the absence of flux, considerable oxidation of the metal occurred. In contrast, in the presence of flux, the degree of oxidation was greatly reduced. In addition, the application of a modest cathodic potential to the flux-covered metal reduced the pick-up of oxygen even further. The results suggest that the use of an appropriate flux combined with cathodic protection when fusion welding titanium and its alloys may offer advantages in circumstances where inert gas shielding is not always feasible, for example, in certain site welding applications.

Although there are numerous historical examples of thermal methods for NDT (e.g. thermally sensitive paints and tapes), the modern era of image-based Thermographic NDT (TNDT) began in the late 1960's, with the advent of the IR video camera. In the ensuing 50 years, the discipline has evolved from a laboratory curiosity to a widely implemented NDT method in the aerospace, automotive and power generation industries. Progress in the field must be attributed, in part, to enormous advances in IR camera and computer technology. The commercial release of focal plane array camera in the 1980's began an uninterrupted trend toward low-noise, high speed, spatial and temperature resolution instruments that provide digital data in real time. The introduction of the PC and the subsequent orders of magnitude improvements in speed, bandwidth and processing power that followed have enabled the development of sophisticated processing algorithms on data from the IR camera in near-real time. Taken together, these advances have provided researchers with the means to dramatically extend the range of TNDT applications in terms of materials, resolution and precision.