Cyclic fatigue testing of surface mooring hardware for the Arabian Sea mixed layer dynamics experiment

The Arabian Sea is strongly forced by monsoon winds. Surface moorings deployed in the Arabian Sea are exposed to high winds and large waves. The waves, generated by strong wind events, impose a dynamic load on all mooring components. The dynamic cycling of mooring components can be so severe that ultimate strength considerations are superseded by the fatigue properties of the standard hardware components. Concerns about all in-line mooring components and their fatigue endurance dictated the need for an independent series of cyclic fatigue tests. The components tested included shackles of various sizes and configurations, wire rope, instrument cages, chain, and a variety of interconnecting links such as weldless sling links and end links. The information gained from these tests was used in the design of the surface moorings deployed in the Arabian Sea by the Upper Ocean Processes group of the Woods Hole Oceanographic Institution. The results of the cyclic fatigue tests conducted in support of the Arabian Sea surface mooring design effort are presented in this report. Recommendations are made with regard to all in-line components for surface moorings where dynamic conditions might be encountered for extended periods. The fatigue test results from shackles, and sling links were compiled to generate an SIN diagram where the cyclic stress amplitude is plotted versus the number of cycles to failure. In addition, the wire rope test results were compiled with historical wire rope data from US steel to generate a SIN diagram for torque balanced 3x19 wire rope. These results can be used in conjunction with future design efforts.Funding was provided by the Office of Naval Research through Grant No. N00014-94-1-0161

An experimental demonstration of effective Curved Layer Fused Filament Fabrication utilising a parallel deposition robot

Fused Filament Fabrication (FFF) is an additive manufacturing (AM) method that relies on the thermal extrusion of a thermoplastic feedstock from a mobile deposition head. Conventional FFF constructs components from stacks of individual extruded layers using tool paths with fixed z-values in each individual layer. Consequently, the manufactured components often contain inherent weaknesses in the z-axis due to the relatively weak thermal fusion bonding that occurs between individual layers, as well as poor surface finish in shallow sloped contours. This study demonstrates the use of Curved Layer FFF (CLFFF) tool paths in tandem with a commercially available parallel, or delta, style FFF system to allow the deposition head to follow the topology of the component. By incorporating a delta robot and CLFFF tool paths in this way, improvements in the surface finish of the manufactured parts has been observed, and time costs associated with Cartesian robot based CLFFF manufacturing have been notably reduced. Furthermore, employing a delta robot provides additional flexibility to CLFFF manufacturing and increases the feasibility of its application for advanced manufacturing. The study has also demonstrated a viable approach to multi-material FFF by decoupling support structure and part manufacture into regions of CLFFF and static z tool pathing in an appropriate fashion.</p

A Survey of Existing Measures for Remedial Readers in the Elementary Schools of Pierce County

It was the purpose of this study to determine what measures are being taken for remedial readers in the elementary schools of second class districts in Pierce County

Arabian Sea mixed layer dynamics experiment : mooring deployment cruise report R/V Thomas Thompson cruise number 46, 14 April-29 April 1995

This report describes in a general manner the work that took place during the R/V Thomas Thompson cruise number 46 which was the mooring turnaround cruise for the moored array program. A detailed description of the WHOI surface mooring and its instrumentation is provided. Information about the XBT and CTD data and near-surface temperature data collected during the cruise is also included.Funding was provided by the Office of Naval Research through Grant No. NOOOl4-94-1-0161

The Subduction experiment : mooring field program and data summary ; Sub 1 June 1991-February 1992 ; Sub 2 February 1992-October 1992 ; Sub 3 October 1992-June 1993

An array of five surface moorings carrying meteorological and oceanographic instrumentation was deployed for a period of two years beginning in June 1991 as part of an Office of Naval Research (ONR) funded Subduction experiment. Three eight month deployments were carried out. The five mooring locations were 18°N 34°W, 18°N 22°W, 25.5°N 29°W, 33°N 22°W and 33°N 34°W. Two Woods Hole Oceanographic Institution (WHOI) and three Scripps Institution of Oceanography (SIO) moorings collected oceanographic and meteorological data, using a 3-meter discus or 2-meter toroid buoy and multiple Vector Measuring Current Meters (VMCMs), an Acoustic Doppler Current Profiler (ADCP) and Brancker temperature recorders (tpods). The surface buoys carried a Vector Averaging Wind Recorder (VAWR) and, on four of the five moorings, an Improved Meteorological Recorder (IMET) which measured wind speed and wind direction, sea surface temperature, air temperature, short wave radiation, barometric pressure and relative humidity. The IMET also measured precipitation. The VMCMs, ADCP and tpods, placed at depths 1 m to 3500 m, measured oceanic velocities and temperatures. This report presents meteorological and oceanographic data from the WHOI Upper Ocean Processes Group (UOP) and the SIO Instrument and Development Group (lDG) instruments and contains summaries of the instruments used, their depths, mooring positions, mooring deployment and recovery times, and data return. Appendices contain information on supplementary Subduction data sets.Funding provided by the Office of Naval Research under Contract No. N00014-90-J-1490

Pan American Climate Study (PACS) mooring recovery and deployment cruise report : R/V Thomas Thompson cruise number 73, 28 November to 26 December 1997

Three surface moorings were recovered and redeployed during R/V Thomas Thompson cruise number 73 in the eastern equatorial Pacific as pan of the Pan American Climate Study (PACS). PACS is a NOAA-funded study with the goal of investigating links between sea-surface temperature variability in the tropical oceans near the Americas and climate over the American continents. The three moorings were deployed near 125°W, spanning the strong meridional sea-surface temperature gradient associated with the cold tongue south of the equator and the warmer ocean north of the equator, near the northernmost, summer location of the Intertopical Convergence Zone. The moored array was deployed to improve the understanding of air-sea fluxes and of the processes that control the evolution of the sea surface temperature field in the region. Two surface moorings, located at 3°S, 125°W and lO°N, 125°W, belonging to the Upper Ocean Processes (UOP) Group at the Woods Hole Oceanographic Institution (WHOI), were recovered after being on station for eight months and redeployed. Two eight-month deployments were planned. A third mooring deployed at the equator and 128°W by the Ocean Circulation Group at the University of South Florida (USF) was also recovered and redeployed. The USF mooring, unfortunately, had to be recovered immediately following redeployment due to a problem with the buoy and instrumentation. The buoys of the two WHOI moorings were each equipped with meteorological instrumentation, including a Vector Averaging Wind Recorder (VAWR), and an Improved Meteorological (IMET) system. The WHOI moorings also carried Vector Measuring Current Meters, single point temperature recorders, and conductivity and temperature recorders located in the upper 200 meters of the mooring line. In addition to the instrumentation noted above, a variety of other instruments, including an acoustic current meter, acoustic doppler current meters, bio-optical instrument packages and an acoustic rain gauge, were deployed during the PACS field program. The USF mooring had an IMET system on the surface buoy and for oceanographic instrumentation, two RD Instruments acoustic doppler current profilers (ADCPs), single-point temperature recorders, and conductivity and temperature recorders. Conductivity-temperature-depth (CTD) profiles were made at each mooring site and during the transit between mooring locations. This report describes, in a general manner, the work that took place during R/V Thomas Thompson cruise number 73. A description of the WHOI moored array and instrumentation is provided. Details of the mooring designs and preliminary data from the CTD profies are included.Funding was provided by the National Oceanic and Atmospheric Administration under Contract No. NA66GPO130