Increasing the Cost Effectiveness of Mechanically Lined Pipe for Risers Installed by Reel-Lay

The use of mechanically lined pipe (MLP) using a thin liner, i.e. 2.5mm, can provide a more cost effective linepipe material solution relative to a standard 3.0mm liner. This is especially the case for the more expensive liner materials with higher corrosion resistance, including Alloy 625. Thin liners, i.e. 2.5mm, can be used without compromising pipeline integrity and performance, whilst still fulfilling design requirements defined in most pipeline design standards, including DNVGL-ST-F101. The suitability of 2.5mm liner MLP has previously been demonstrated in service over a range of pipeline bundle projects installed with the controlled depth tow method, but not to date for risers installed by reel-lay. This paper presents the details and test results of the qualification programme to support its use for both flowlines and risers installed by reel-lay. The qualification MLP test pipes, which comprised an outer diameter (OD) 219.1mm × wall thickness (WT) 15.9mm X65 + 2.5mm Alloy 625, were manufactured using established manufacturing procedures and facilities. Reeling and fatigue test strings were fabricated using qualified welding solutions. The fabricated test strings were subject to internal visual inspection and dimensional measurement using laser metrology in order to provide a benchmark for comparison post reeling. The test strings were given a simulated reeling procedure using bending and straightening formers representative of a reel-lay vessel with the smallest reel hub diameter, this being a conservative material straining condition. An internal pressurisation technique, as per standard installation practice for the present pipe lay contractor for MLP, was applied during the simulated reeling procedure. Post reeling the internal laser metrology inspection procedure was repeated in order to confirm the integrity of the liner and to check for the presence of any evidence of liner wrinkling or damage. Subsequently, full scale fatigue testing was performed using the high frequency resonance bending procedure. Testing was performed to ultimate failure to determine the fatigue endurance limit of the thin liner MLP. Additionally Finite Element Analysis (FEA) was performed to further validate the satisfactory reeling performance of the thin liner MLP. The FE numerical analysis embraced manufacture of the MLP pipe and test samples coupled with the reeling procedure. Sensitivity analysis on pipe strength and geometrical mismatch was performed to demonstrate the robustness of the linepipe material solution and reeling procedure. All of the critical qualification activities were performed and verified by DNVGL and in accordance with the guidance of DNVGL-RP-A203 Technology Qualification process. The paper highlights the qualification programme performed to enable the cost effective use of thin liner MLP, specifically Alloy 625, for risers installed by reel-lay.

Determining the duration of an ultra-intense laser pulse directly in its focus

Ultra-intense lasers facilitate studies of matter and particle dynamics at unprecedented electromagnetic field strengths. In order to quantify these studies, precise knowledge of the laser’s spatiotemporal shape is required. Due to material damage, however, conventional metrology devices are inapplicable at highest intensities, limiting laser metrology there to indirect schemes at attenuated intensities. Direct metrology, capable of benchmarking these methods, thus far only provides static properties of short-pulsed lasers with no scheme suggested to extract dynamical laser properties. Most notably, this leaves an ultra-intense laser pulse’s duration in its focus unknown at full intensity. Here we demonstrate how the electromagnetic radiation pattern emitted by an electron bunch with a temporal energy chirp colliding with the laser pulse depends on the laser’s pulse duration. This could eventually facilitate to determine the pulse’s temporal duration directly in its focus at full intensity, in an example case to an accuracy of order 10% for fs-pulses, indicating the possibility of an order-of magnitude estimation of this previously inaccessible parameter.

Synthesis of video and 3D laser metrology to reconstruct a vehicle vs pedestrian collision: a case study

Human Factors investigations of vehicle-versus-pedestrian collisions can be challenging due to a lack of objective data. While sources such as electronic data recorders on vehicles are typically sensitive to collisions with other vehicles or large-mass objects, pedestrian strikes often fail to generate sufficient accelerative forces to reach triggering thresholds. The present work details a case study of the reconstruction of a vehicle-versus-pedestrian collision. While the vehicle data recorder failed to capture the collision, a security camera was located approximately 360 feet away which partially-captured the crash site. Data from this security camera and 3D laser scan data were combined and analyzed to determine the pre-impact speeds of the vehicle and pedestrians. Comparison of the calculated speeds to normative data suggest this is a reliable method for analysis of challenging video data. Results and future work are discussed.

Hollow-Core Fiber Technology: The Rising of “Gas Photonics”

Since their inception, about 20 years ago, hollow-core photonic crystal fiber and its gas-filled form are now establishing themselves both as a platform in advancing our knowledge on how light is confined and guided in microstructured dielectric optical waveguides, and a remarkable enabler in a large and diverse range of fields. The latter spans from nonlinear and coherent optics, atom optics and laser metrology, quantum information to high optical field physics and plasma physics. Here, we give a historical account of the major seminal works, we review the physics principles underlying the different optical guidance mechanisms that have emerged and how they have been used as design tools to set the current state-of-the-art in the transmission performance of such fibers. In a second part of this review, we give a nonexhaustive, yet representative, list of the different applications where gas-filled hollow-core photonic crystal fiber played a transformative role, and how the achieved results are leading to the emergence of a new field, which could be coined “Gas photonics”. We particularly stress on the synergetic interplay between glass, gas, and light in founding this new fiber science and technology.

Vorrichtungslose Montage von Karosseriebauteilen*/Fixtureless assembly of car body components - Virtual assembly of flexible joining processes in automotive prototype construction using laser radar

Im automobilen Prototypenbau werden starre Vorrichtungen genutzt, um Karosseriebauteile für Fügeprozesse zueinander auszurichten. Geringe Stückzahlen der Vorserie führen zu kurzen Nutzungsphasen der aufwendig aufgebauten und eingemessenen Vorrichtungen. Im Beitrag wird ein Ansatz zur vorrichtungslosen Montage durch den Einsatz von Industrierobotik und laserbasierter Messtechnik vorgestellt. Die Ergebnisse zeigen, dass sich für einzelne Baugruppen Möglichkeiten für das vorrichtungslose Fügen in der industriellen Praxis ergeben.   Rigid fixtures are used in automotive prototype construction to align body parts for joining processes. Small quantities of the prototype series lead to short usage of the laboriously assembled and calibrated fixtures. In the following, an approach of fixtureless assembly using industrial robots and laser metrology is presented. The results show that some fixtures and jigs can be dispensed with for individual components in industrial practice.