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Stress intensity factor solutions for cracks in threaded fasteners

Description: Nondimensional stress intensity factor (K) solutions for continuous circumferential cracks in threaded fasteners were calculated using finite element methods that determined the energy release rate during virtual crack extension. Assumed loading conditions included both remote tension and nut loading, whereby the effects of applying the load to the thread flank were considered. In addition, K solutions were developed for axisymmetric surface cracks in notched and smooth round bars. Results showed that the stress concentration of a thread causes a considerable increase in K for shallow cracks, but has much less effect for longer cracks. In the latter case, values of K can be accurately estimated from K solutions for axisymmetric cracks in smooth round bars. Nut loading increased K by about 50% for shallow cracks, but this effect became negligible at crack depth-to-minor diameter ratios (a/d) greater than 0.2. An evaluation of thread root acuity effects showed that root radius has no effect on K when the crack depth exceeds 2% of the minor diameter. Closed-form K solutions were developed for both remote-loading and nut-loading conditions and for a wide range of thread root radii. The K solutions obtained in this study were compared with available literature solutions for threaded fasteners as well as notched and smooth round bars.
Date: February 1, 1999
Creator: Oster, D.M. & Mills, W.J.
Partner: UNT Libraries Government Documents Department


Description: This calculation applies to the Constructor's design of the proposed jacking bracket for the W6 x 20 steel set. The specific features of the jacking bracket evaluated in this analysis are the shear on the bracket bolts, and the effects of the applied moment on the W6 x 20 steel set beam segment.
Date: March 28, 1996
Creator: Stine, Marvin D.
Partner: UNT Libraries Government Documents Department


Description: This paper provides a brief history of the U.S. Type B 6M specification container, its introduction into U.S. Code of federal regulations and its scheduled elimination three decades later. The paper also presents development, testing and deployment by the Department of Energy (DOE) of an enhanced drum closure called the 'Blanton Clamshell' (patent pending) that was designed to replace the standard open-head C-ring closure for the 55- and 85-gallon drums described in the 6M specification to extend their safe use. Nuclear Filter Technology has the Exclusive License for Clamshell production. Drum packages utilizing the standard C-ring closure have been a main-stay for over a half of a century in the national and international nuclear industry for shipping radioactive materials and will remain so in the foreseeable future. Drum package use in the U.S. increased heavily in the 1950's with development of the Weapons Complex and subsequently the commercial nuclear reactor industry.
Date: October 18, 2007
Creator: Blanton, P
Partner: UNT Libraries Government Documents Department

EXAMINATION OF SHIPPING PACKAGES 9975-01818, 9975-01903 AND 9975-02287

Description: Three 9975 shipping packages were examined to investigate the non-conforming condition of an axial air gap greater than 1 inch. This condition typically indicates the presence of excess moisture in the fiberboard overpack, and may be accompanied by degradation in the fiberboard properties. The package with the largest axial air gap (9975-01818, with an air gap of 1.437 inches) was found to contain significant excess moisture, and the lower fiberboard assembly was covered with mold and was significantly degraded in strength. This condition is very similar to that observed previously in package 9975-01819. Both packages (-1818 and -1819) appear to contain a similar amount of excess moisture, which was previously estimated for 9975-01819 as {approx}2.5 liters. The condition of 9975-01818 was also evidenced by several rust spots along the bottom chime of the drum, although no significant rust was noted on the closure bolts. Packages 9975-01903 and 9975-02287 were also examined. The axial air gap in these two packages was less than in 9975-01818, but still exceeded 1 inch. These two packages contained elevated moisture levels, although not significantly higher than seen in other 'typical' packages. The fiberboard in these two packages was of sound integrity, and appeared generally consistent with undegraded material. A few small patches of mold on and near the bottom of the fiberboard in 9975-01903 appeared dormant. No mold was observed on package 9975-02287. The SPA will provide recommendations on possible follow-up activities with these three packages. This might include a demonstration in SRNL of whether removal of the caplugs from similar packages would facilitate removal of excess moisture. Future efforts should also include an assessment of using the 1 inch axial gap criterion as a valid indicator of fiberboard degradation.
Date: November 18, 2009
Creator: Daugherty, W.
Partner: UNT Libraries Government Documents Department

Finite element modeling for validation of structural damage identification experimentation.

Description: The project described in this report was performed to couple experimental and analytical techniques in the field of structural health monitoring and darnage identification. To do this, a finite dement model was Constructed of a simulated three-story building used for damage identification experiments. The model was used in conjunction with data from thie physical structure to research damage identification algorithms. Of particular interest was modeling slip in joints as a function of bolt torque and predicting the smallest change of torque that could be detected experimentally. After being validated with results from the physical structure, the model was used to produce data to test the capabilities of damage identification algorithms. This report describes the finite element model constructed, the results obtained, and proposed future use of the model.
Date: January 1, 2001
Creator: Stinemates, D. W. (Daniel W.) & Bennett, J. G. (Joel G.)
Partner: UNT Libraries Government Documents Department

Damping dependence on bolt torque for a simple frame structure.

Description: Damping quantifies the energy dissipation properties of a material or system under cyclic stress. Damping is also one of the most difficult properties of a mechanical structure to model using first principles (Ewins, 2002) . Damping in uniform metal structures is often low. In built up structures dissipation occurs at mechanical joints or through introduction of viscoelastic materials ( Ungar, 1973, Goodman, 1996) . Energy dissipation at joints, associated with microslip, macroslip and hystersis increases the total damping of a structure so built up structures virtually always have greater damping than structures composed of a single part . Since damping is sensitive to interface properties, damping is a good feature for quantifying interface condition.
Date: January 1, 2003
Creator: Hunter, N. F. (Norman F.) & Paez, Thomas L.,
Partner: UNT Libraries Government Documents Department

Samus Counter Lifting Fixture

Description: A lifting fixture has been designed to handle the Samus counters. These counters are being removed from the D-zero area and will be transported off site for further use at another facility. This fixture is designed specifically for this particular application and will be transferred along with the counters. The future use of these counters may entail installation at a facility without access to a crane and therefore a lift fixture suitable for both crane and/or fork lift usage has been created The counters weigh approximately 3000 lbs. and have threaded rods extended through the counter at the top comers for lifting. When these counters were first handled/installed these rods were used in conjunction with appropriate slings and handled by crane. The rods are secured with nuts tightened against the face of the counter. The rod thread is M16 x 2({approx}.625-inch dia.) and extends 2-inch (on average) from the face of the counter. It is this cantilevered rod that the lift fixture engages with 'C' style plates at the four top comers. The strongback portion of the lift fixture is a steel rectangular tube 8-inch (vertical) x 4-inch x .25-inch wall, 130-inch long. 1.5-inch square bars are welded perpendicular to the long axis of the rectangular tube at the appropriate lift points and the 'C' plates are fastened to these bars with 3/4-10 high strength bolts -grade 8. Two short channel sections are positioned-welded-to the bottom of the rectangular tube on 40 feet centers, which are used as locators for fork lift tines. On the top are lifting eyes for sling/crane usage and are rated at 3500 lbs. safe working load each - vertical lift only.
Date: May 27, 1998
Creator: Stredde, H.
Partner: UNT Libraries Government Documents Department

Metallurgical examination of gun barrel screws

Description: The examination was conducted to determine the extent of degradation that had occurred after a series of firings; these screws prevent live rounds of ammunition from being loaded into the firing chamber. One concern is that if the screw tip fails and a live round is accidentally loaded into the chamber, a live round could be fired. Another concern is that if the blunt end of the screw begins to degrade by cracking, pieces could become small projectiles during firing. All screws used in firing 100 rounds or more exhibited some degree degradation, which progressively worsened as the number of rounds fired increased. (SEM, metallography, x-ray analysis, and microhardness were used.) Presence of cracks in these screws after 100 fired rounds is a serious concern that warrants the discontinued use of these screws. The screw could be improved by selecting an alloy more resistant to thermal and chemical degradation.
Date: June 1, 1996
Creator: Bird, E.L. & Clift, T.L.
Partner: UNT Libraries Government Documents Department

Wire brush fastening device

Description: A fastening device is provided which is a variation on the conventional nut and bolt. The bolt has a longitudinal axis and threading helically affixed thereon along the longitudinal axis. A nut having a bore extending therethrough is provided. The bore of the nut has a greater diameter than the diameter of the bolt so the bolt can extend through the bore. An array of wire bristles are affixed within the bore so as to form a brush. The wire bristles extend inwardly from the bore and are constructed and arranged of the correct size, length and stiffness to guide the bolt within the bore and to restrain the bolt within the bore as required. A variety of applications of the wire brush nut are disclosed, including a bolt capture device and a test rig apparatus.
Date: August 31, 1993
Creator: Meigs, R.A.
Partner: UNT Libraries Government Documents Department

Test plan and report for maxi-drill model 3030 foot-clamp

Description: This test plan and report defines the testing performed to determine whether the MAXIDRILL Model 3030 Footclamp meets the needs of RMCS operations. This document reports the outcome of the test pesformed. The new footclamp will enhance the safety of RMCS operations.
Date: June 24, 1999
Creator: Boger, R. M.
Partner: UNT Libraries Government Documents Department

Pipeline Structural Health Monitoring Using Macro-fiber Composite Active Sensors

Description: The United States economy is heavily dependent upon a vast network of pipeline systems to transport and distribute the nation's energy resources. As this network of pipelines continues to age, monitoring and maintaining its structural integrity remains essential to the nation's energy interests. Numerous pipeline accidents over the past several years have resulted in hundreds of fatalities and billions of dollars in property damages. These accidents show that the current monitoring methods are not sufficient and leave a considerable margin for improvement. To avoid such catastrophes, more thorough methods are needed. As a solution, the research of this thesis proposes a structural health monitoring (SHM) system for pipeline networks. By implementing a SHM system with pipelines, their structural integrity can be continuously monitored, reducing the overall risks and costs associated with current methods. The proposed SHM system relies upon the deployment of macro-fiber composite (MFC) patches for the sensor array. Because MFC patches are flexible and resilient, they can be permanently mounted to the curved surface of a pipeline's main body. From this location, the MFC patches are used to monitor the structural integrity of the entire pipeline. Two damage detection techniques, guided wave and impedance methods, were implemented as part of the proposed SHM system. However, both techniques utilize the same MFC patches. This dual use of the MFC patches enables the proposed SHM system to require only a single sensor array. The presented Lamb wave methods demonstrated the ability to correctly identify and locate the presence of damage in the main body of the pipeline system, including simulated cracks and actual corrosion damage. The presented impedance methods demonstrated the ability to correctly identify and locate the presence of damage in the flanged joints of the pipeline system, including the loosening of bolts on the flanges. In addition to ...
Date: March 1, 2006
Creator: Thien, A.B.
Partner: UNT Libraries Government Documents Department

Lifting BLS Power Supplies

Description: This note describes BLS power supplies lifting techniques and provides stress calculations for lifting plate and handles bolts. BLS power supply weight is about 120 Lbs, with the center of gravity shifted toward the right front side. A lifting plate is used to attach a power supply to a crane or a hoist. Stress calculations show that safety factors for lifting plate are 12.9 (vs. 5 required) for ultimate stress and 5.7 (vs. 3 required) for yield stress. Safety factor for shackle bolt thread shear load is 37, and safety factor for bolts that attach handles is 12.8.
Date: August 1, 2007
Creator: Sarychev, Michael
Partner: UNT Libraries Government Documents Department


Description: Radioactive material package containment vessels typically employ bolted closures of various configurations. Closure bolts must retain the lid of a package and must maintain required seal loads, while subjected to internal pressure, impact loads and vibration. The need for insuring that the specified preload is achieved in closure bolts for radioactive materials packagings has been a continual subject of concern for both designers and regulatory reviewers. The extensive literature on threaded fasteners provides sound guidance on design and torque specification for closure bolts. The literature also shows the uncertainty associated with use of torque to establish preload is typically between 10 and 35%. These studies have been performed under controlled, laboratory conditions. The ability to insure required preload in normal service is, consequently, an important question. The study described here investigated the relationship between indicated torque and resulting bolt load for a typical radioactive materials package closure using methods available under normal service conditions.
Date: February 16, 2010
Creator: Smith, A.
Partner: UNT Libraries Government Documents Department

Stress and Sealing Performance Analysis of Containment Vessel

Description: This paper presents a numerical technique for analyzing the containment vessel subjected to the combined loading of closure-bolt torque and internal pressure. The detailed stress distributions in the O-rings generated by both the torque load and the internal pressure can be evaluated by using this method. Consequently, the sealing performance of the O-rings can be determined. The material of the O-rings can be represented by any available constitutive equation for hyperelastic material. In the numerical calculation of this paper, the form of the Mooney-Rivlin strain energy potential is used. The technique treats both the preloading process of bolt tightening and the application of internal pressure as slow dynamic loads. Consequently, the problem can be evaluated using explicit numerical integration scheme.
Date: May 24, 2005
Creator: WU, TSU-TE
Partner: UNT Libraries Government Documents Department


Description: The essential difference between Revision 1 and the original issue of this report is in the spring constants used to model the anchor bolt response for the anchor bolts that tie the steel dome of the primary tank to the concrete tank dome. Consequently, focus was placed on the changes in the anchor bolt responses, and a full reevaluation of all tank components was judged to be unnecessary. To confirm this judgement, primary tank stresses from the revised analysis of the BES-BEC case are compared to the original analysis and it was verified that the changes are small, as expected.
Date: January 14, 2009
Creator: Mackey, T. C.; Abatt, F. G. & Rinker, M. W.
Partner: UNT Libraries Government Documents Department

Lifting Beam Design/Analysis for the Data Acquisition and Control System Trailer

Description: This supporting document details calculations completed to properly design an adjustable lifting beam. The main use of the lifting beam is to hoist the Data Acquisition and Controls Systems (DACS) trailer over a steam line. All design work was completed using the American Institute of Steel Construction, Manual of Steel Construction (AISC, 1989) and Hanford Hoisting and Rigging Manual (WHC, 1992).
Date: March 15, 1993
Creator: Mackey, T. C. & Benegas, T. R.
Partner: UNT Libraries Government Documents Department

Engineering Sheets of 12 Metre Solenoid

Description: The solenoid design follows closely the considerations qiven in {bar p} note 116. In particular we try to make the solenoid undivided, but with a centre tap for the cooling water. We found a variant for the centre tap, so that the two layers are now electrically in series. Due to the very long length, it seems better not to fill the clearance between return yoke and OD of the second layer with epoxy. Instead, we support and adjust the coil every 2 m with three bolts at 120 deqrees screwed in the return yoke. The latter is then supposed to be sufficiently stiff, so as to give the weaker mandrel the desired straightness. We give a positive pitch, i.e. somewhat more than the width of the copper section including insulation and tolerances. The precise pitch cannot be stated here, because the copper section will be somewhat trapezoidal. How much, depends on the winding procedure. The layers are epoxy impregnated and solidair with the mandrel. The Figures show an axial section and the construction of the central water tap. The dimensions shown are on the assumption of a free choice of the diameters of return yoke and mandrel. This may not be the case, and a reshuffling of the dimensions may be needed.
Date: March 30, 1981
Creator: Krienen, Frank
Partner: UNT Libraries Government Documents Department

Control Dewar and VLPC Bayonet Can Platform Connection Design and Analysis

Description: The four connections for the control dewar and VLPC bayonet can platform are designed, using finite element analysis, to carry all dead weight and live loads. Based on the loads applied to the platform, two 1 inch thick plates and two 3/4 inch thick brackets made of ASTM A572-Grade 42 are required. The 1 inch thick plate requires a 3/8 inch thick intermediate steel material, between the 8-inch x 4-inch x 1/4-inch boom and the plate, for load reinforcement as well as weld area reinforcement. Both the plates and the brackets require 3/4 inch steel bolt connections.
Date: July 29, 1997
Creator: Kuwazaki, A.
Partner: UNT Libraries Government Documents Department

Reusable vibration resistant integrated circuit mounting socket

Description: This invention discloses a novel form of socket for integrated circuits to be mounted on printed circuit boards. The socket uses a novel contact which is fabricated out of a bimetallic strip with a shape which makes the end of the strip move laterally as temperature changes. The end of the strip forms a barb which digs into an integrated circuit lead at normal temperatures and hold it firmly in the contact, preventing loosening and open circuits from vibration. By cooling the contact containing the bimetallic strip the barb end can be made to release so that the integrated circuit lead can be removed from the socket without damage either to the lead or to the socket components.
Date: December 31, 1993
Creator: Evans, C.N.
Partner: UNT Libraries Government Documents Department

Second Annual Maintenance, Inspection, and Test Report for PAS-1 Cask Certification for Shipping Payload B

Description: The Nuclear Packaging, Inc. (NuPac), PAS-1 cask is required to undergo annual maintenance and inspections to retain certification in accordance with U.S. Department of Energy (DOE) Certificate of Compliance USA/9184B(U) (Appendix A). The packaging configuration being tested and maintained is the NuPac PAS-1 cask for Payload B. The intent of the maintenance and inspections is to ensure the packaging remains in unimpaired physical condition. Two casks, serial numbers 2162-026 and 2162-027, were maintained, inspected, and tested at the 306E Development, Fabrication, and Test Laboratory, located at the Hanford Site's 300 Area. Waste Management Federal Services, Inc. (WMFS), a subsidiary of GTS Duratek, was in charge of the maintenance and testing. Cogema Engineering Corporation (Cogema) directed the operations in the test facility. The maintenance, testing, and inspections were conducted successfully with both PAS-1 casks. The work conducted on the overpacks included weighing, gasket replacement, and plastic pipe plug and foam inspections. The work conducted on the secondary containment vessel (SCV) consisted of visual inspection of the vessel and threaded parts (i.e., fasteners), visual inspection of sealing surfaces, replacement of O-ring seals, and a helium leak test. The work conducted on the primary containment vessel (PCV) consisted of visual inspection of the vessel and threaded parts (i.e., fasteners), visual inspection of sealing surfaces, replacement of O-ring seals, dimensional inspection of the vessel bottom, a helium leak test, and dye penetrant inspection of the welds. The vermiculite material used in the cask rack assembly was replaced.
Date: October 9, 2000
Creator: KELLY, D.J.
Partner: UNT Libraries Government Documents Department

Evaluation of PEGIT duct connection system

Description: Most air duct system components are assembled in the field and are mechanically fastened by sheet metal screws (for sheet metal-to-sheet metal) or by drawbands (for flex duct-to-sheet metal). Air sealing is separate from this mechanical fastening and is usually achieved using tape or mastic products after mechanical fastening. Field observations have shown that mechanical fastening rarely meets code or manufacturers requirements and that sealing procedures are similarly inconsistent. To address these problems, Proctor Engineering Group (PEG) is developing a system of joining ducts (called PEGIT) that combines the mechanical fastening and sealing into a single self-contained procedure. The PEGIT system uses a shaped flexible seal between specially designed sheet metal duct fittings to both seal and fasten duct sections together. Figure 1 shows the inner duct fitting complete with rubber seal. This seal provides the air seal for the completed fitting and is shaped to allow the inner and outer fittings to slide together, and then to lock the fittings in place. The illustration in Figure 2 shows the approximate cross section of the rubber seal that shows how the seal has a lip that is angled backwards. This angled lip allows the joint to be pushed together by folding flat but then its long axis makes it stiff in the pulling apart direction. This study was undertaken to assist PEG in some of the design aspects of this system and to test the performance of the PEGIT system. This study was carried out in three phases. The initial phase evaluated the performance of a preliminary seal design for the PEGIT system. After the first phase, the seal was redesigned and this new seal was evaluated in the second phase of testing. The third phase performed more detailed testing of the second seal design to optimize the production tolerances ...
Date: August 1, 2003
Creator: Walker, Iain S.; Brenner, Douglas E.; Sherman, Max H. & Dickerhoff, Darryl J.
Partner: UNT Libraries Government Documents Department