Submission of proposals
U.S. Army Construction Engineering Research Laboratory (CERL)
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| U.S. Army Construction Engineering Research Laboratory (CERL)
A00-142 TITLE: Field-Portable Infrastructure Fiber-Reinforced Polymer Composite Inspection & Evaluation System using Ultrasound Technologies TECHNOLOGY AREAS: Materials/Processes, Space Platforms OBJECTIVE: Design, develop and demonstrate a portable fiber-reinforced polymer (FRP) composite inspection and evaluation system that can be used in the field to assess infrastructure composites. The system must utilize ultrasound technologies and must be capable of inspecting 1/2" thick glass, carbon and aramid reinforced polymer composite systems used as upgrades to existing infrastructure or as new structural elements (e.g. All-composite I-beam). The inspection and evaluation system should be able to identify flaws or damage 0.05" in size in multiple damage situations including debonding between composite and concrete/masonry substrate, delamination within the composite or cracking that can lead to incipient failure. Part of the inspection and evaluation system includes a simple cable-free, battery powered, hand-held device for rapid repair and replacement assessment of structural composites. DESCRIPTION: Much work has focused on various techniques for the non-destructive inspection and evaluation (NDI/NDE) of fiber-reinforced composite systems. Many of these applications have focused on the inspection of metallic or non-infrastructure FRP composite systems (e.g. aerospace). The recent push to use FRP composites in a variety of infrastructure applications has driven the need to develop (or tailor) these technologies to meet the NDI/NDE requirements of infrastructure composites. However, most of the proposed systems to date involve bulky equipment and/or wiring that makes routine inspection and evaluation impractical in the field. A field-portable, battery powered ultrasound inspection system would allow field engineers to routinely inspect FRP composite systems in a minimal amount of time. Ultrasonic technologies have been used extensively to inspect metallic welds and aerospace FRP composites by providing distributed damage information in A-, B- and C-scan modes. Such a system would also provide distributed QA/QC information and damage detection capabilities. A hand-held display of the inspection results must be able to identify the location and type of damage within the 0.05" resolution requirements specified in the objective. SBIR proposals must also meet the following five criteria: The system must 1) use ultrasound technologies with the ultrasound sensor completed contained within a single unit assessment system; 2) use battery power sufficient for continuous 14-day operation; 3) weigh 2.0 pounds or less and be 6" x 6" x 2" or less in size; 4) contain PCMCIA interface capabilities for data storage and later computer retrieval, and 5) be designed for the assessment of infrastructure composites and contain built-in infrastructure composite assessment tools with built-in alarms. PHASE I: Develop and demonstrate the manufacturing techniques to fabricate a field-portable FRP composite NDI/NDE system based on ultrasound technologies. The system must contain a hand-held interface to provide the user with a quick assessment of an inspection. The technique must be validated on an FRP composite system conforming to the criteria established in the objective. Such a system will assist in establishing Army standards on inspecting infrastructure composites. PHASE II: Develop a lightweight, portable infrastructure FRP composite NDI/NDE system. The prototype ultrasound inspection/evaluation system will be used to inspect an Army infrastructure FRP composite upgraded system. Equipment inspection and data assessment procedures are to be documented in a report. PHASE III DUAL USE APPLICATIONS: Like the Army, other DoD branches are utilizing FRP composites for infrastructure applications. Therefore, the inspection and evaluation system developed in this SBIR offers enhanced inspection capabilities to the Triservices community. In addition, the entire civilian sector that utilizes FRP composites in a variety of aerospace, marine or sporting applications can benefit from the portability of this technology. Developing a technique that is portable and provides composite inspection and evaluation information, opens the market for further use of FRP composites in infrastructure. A hand-held inspection interface saves on the cost of lengthy FRP composite inspection analyses. This program will provide the principal researchers with a unique opportunity to develop a standard for the in-service inspection of infrastructure composites. OPERATING AND SUPPORT COST (OSCR) REDUCTION: A portable FRP composite inspection and evaluation system will allow the field to use FRP composites in infrastructure applications with confidence. Demonstrations using FRP composites have shown dramatic cost savings over traditional methods and materials. However, a lack of confidence in long term durability and inspection techniques has made designers and engineers reluctant to utilize these materials. This portable inspection and evaluation system will allow the field to take advantage of these cost savings by giving them the ability to asses the structural integrity of the FRP composite materials. REFERENCES: Klinkhachorn P., S. Nomani, W. Chatwiriya, U.B. Halabe and S. Petro. 1998. "Development of a Portable Ultrasonic Timber Properties Monitoring Device," IEEE Proceedings of Thirtieth Southeastern Symposium on System Theory (Cat No. 98EX148), New York NY, pp. 467-71. Stanley B.D., L. Bustemante and J.C. Earthman. 1996. "Novel Instrumentation for Rapid Assessment of Internal Damage in Composite Materials," TMS Nondestructive Evaluation and Materials Properties III, Warrendale PA, pp. 97-100. Long, E.R., S.M. Kullerd, P.H. Johnston and E.M. Madaras. 1990. "Ultrasonic Detection and Identification of Fabrication Defects in Composites," NASA Technical Report #CP3104, First NASA Advanced Composite Technology Conference, Seattle WA, 29 Oct - 01 Nov 1990. Anastasi, R.F., A.D. Friedman, M.K. Hinders, and E.I. Madaras. 1997. "Nondestructive Evaluation of Damage in Stitched Composites using Laser Based Ultrasound," International Workshop on Structural Health Monitoring, Stanford CA, 18-20 September 1997. KEYWORDS: sensor, structural health monitoring, fiber-reinforced polymer composite, infrastructure, and ultrasound technologies A00-143 TITLE: Microencapsulated Phase Change Materials (MPCM) in Thermal Energy Systems TECHNOLOGY AREAS: Materials/Processes, Space Platforms OBJECTIVE: The objective of this work is to develop novel micro-encapsulated Phase Change Materials (MPCM) for use in PCM slurries. The PCM slurries will be employed in Thermal Energy Systems to reduce thermal losses, reduce initial construction costs and improve the fluidity and transient thermal behavior of the slurry through micro-encapsulation of the PCM. DESCRIPTION: The use of novel Phase Change Materials (PCM), in either solid or encapsulated form, in heating and cooling systems has the potential of reducing initial system construction costs and ongoing distribution systems losses. PCMs produce a fundamental change in the fluid dynamics resulting in laminar flows. PCMs also provide a significantly increased heat transfer coefficient as compared to water. This allows thermal energy plants to reduce flow rates for comparable heating and cooling levels. In addition PCMs allow for either smaller pipes in new systems or increased thermal capacity for existing distribution systems. By operating at lower extremes of temperatures, savings will be realized for a reduced potential for transmission energy loss and/or a decreased need for insulation. The current problems associated with PCMs are heat exchanger fouling and maintaining fluidity of the PCM slurry. This research seeks to overcome these obstacles by microencapsulating the PCM to improve fluidity and heat transfer properties associated with the phase change. PHASE I: A. Based on a survey of the current state of the art novel materials will be developed and optimized for microencapsulation PCMs. This includes development and optimization of candidate phase change materials with regard to their heat capacity, conductivity, material compatibility, heat transfer rate and fluid dynamics. Prime parameters include the Froude number, particle/pipe diameter ratio, particle diameter/boundary layer thickness ratio, and particle/fluid thermal conductivity ratio. B. Perform laboratory bench scale experiments to optimize parameters for system wide application. Included in this effort will be the optimal sizing of the particles relative to the transport boundary layer thickness to achieve the greatest reduction in pressure drop. For system designs that normally employ a low temperature drop (i.e. small “delta-T”) and high flow the amount of PCM slurry loading will be investigated to determine if essentially identical pressure drops can be achieved relative to a pure, conventional working fluid. If achievable this would allow existing design tools and simulations to be used. Also investigated will be PCM slurry loading of system designs employing high temperature drops. It is expected that minimal loading will serve to relaminarize the flow while minimizing the impact on thermal density. This will in turn reduce the convective heat transfer coefficient and thus thermal losses associated with system wide distribution. Needed modifications of heat exchanger design will also be investigated to ensure turbulent flow conditions when PCM slurries contact heat transfer surfaces. PHASE II: A. Perform a pilot scale test at an installation and quantitatively measure most critical performance parameters. This effort will include the production of adequate quantities of a prototype micro-encapsulated PCM material. A test plan for the pilot scale testing will be developed and will include full quantitative details of PCM performance evaluation. Included will be measurements of sensible heat transfer, both in transit and at delivery, as well as flow characteristics. The Phase II report will fully document the effort and include any and all start up or shut down problems. Also included in the report will be a detailed cost benefit analysis relative to current conventional technology as well as a preliminary commercialization plan. PHASE III DUAL USE APPLICATIONS: This technology has the potential to increase efficiencies and reduce costs of heat transfer systems. This is applicable to thermal energy systems in both the federal and private sectors. OPERATING AND SUPPORT COST (OSCR) REDUCTION: To put the potential benefits in perspective, a simplified economic analysis based on data from Ft. Bragg and Ft. McClellan was done. In this analysis it was assumed that a relaminarized slurry flow has heat transfer characteristics similar to that of the pure fluid in laminar flow. This optimistic assumption was balanced by the use of a pessimistic estimate of the cost of the slurry based on using a MPCM consisting of a paraffin wax in a cross-linked polymer shell, which currently costs about $1000/gal and is expected to drop to about $100/gal in production quantities. The results of this analysis indicate that the simple payback is in the range of 2.5 to 25 years, depending on which cost is used for the PCM material. REFERENCES: Kasza, K.E., and Chen, M. M., “Assessment of Impact of Advanced Energy Transmission Fluids on District Heating and Cooling Systems,” Argonne National Laboratory, Argonne, Illinois, DE88 001589, September 1987. Liu, K. V., Chois, U. S., and Kasza, K. E., “Measurements of Pressure Drop and Heat Transfer in Turbulent Pipe Flows of Particulate Slurries,” Argonne National Laboratory, Argonne, Illinois, DE88 013622, May 1988. Park, J. T., Mannheimer, R. J., Grimely, T. A., and Morrow, T. B., “Experiments on Densely-Loaded Non-Newtonian Slurries in Laminar and Turbulent Pipe Flows,” Southwest Research Institute, San Antonio, Texas, DE88 006209, February 1988. McLain, H. A., and Wasserman, D. M., “Test of WHDP at Fort Bragg, North Carolina,” Oak Ridge National Laboratory, DOE contract # DE-AC05-84OR21400, February 1990. Van Wylen, G. J., and Sonntag, R. E., “Fundamentals of Classical Thermodynamics,” John Wiley & Sons, New York, 1978. Colvin, D. P., Bryant, Y. B., Mulligan, J. C., and Duncan, J. D., “Microencapsulated Phase Change Material Heat Transfer Systems,” Triangle Research and Development Corp., WRDC-TR-89-3072, August 1989. KEYWORDS: Phase Change Materials, Thermal Energy Systems Download 1.22 Mb. Share with your friends:
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