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Method for stress analysis of a swept propeller

Description: Report presenting the methods used to estimate and reduce the stresses in a swept propeller to be tested in the 8-foot high-speed tunnel. Specific information regarding the method for determination of stresses, method for reduction of moments, and relative magnitude of factors is provided.
Date: September 27, 1948
Creator: Whitcomb, Richard T.
Partner: UNT Libraries Government Documents Department

Stress Analysis of Circular Semimonocoque Cylinders With Cutouts by a Perturbation Load Technique

Description: "A method is presented for analyzing the stresses about a cutout in a circular cylinder of semimonocoque construction. The method involves the use of so-called perturbation solutions which are superposed on the stress distribution that would exist in the structure with no cutout in such a way as to give the effects of a cutout. The method can be used for any loading case for which the structure without the cutout can be analyzed and is sufficiently versatile to account for stringer and shear reinforcement about the cutout" (p. 1).
Date: September 1954
Creator: McComb, Harvey G., Jr.
Partner: UNT Libraries Government Documents Department

Charts for stress analysis of reinforced circular cylinders under lateral loads

Description: Report presenting charts with coefficients for the stress analysis of a reinforced circular cylinder. They allow for the rapid determination of sheer flows and direct stresses in the sheet of a cylinder as well as the shear forces, axial forces, and bending moments in the rings. Separate charts are also given for three basic ring loadings.
Date: May 1947
Creator: Kempner, Joseph & Duberg, John E.
Partner: UNT Libraries Government Documents Department

Tables of Coefficients for the Analysis of Stresses About Cutouts in Circular Semimonocoque Cylinders with Flexible Rings

Description: Note presenting tables of coefficients which facilitate the stress analysis of circular semimonocoque cylinders with cutouts by the method published in a previous report. When the values of two simple structural parameters are known, use of the coefficients enables shear flows and stringer loads in the neighborhood of a cutout to be calculated.
Date: July 1955
Creator: McComb, Harvey G., Jr. & Low, Emmet F., Jr.
Partner: UNT Libraries Government Documents Department

The Physical Connection and Magnetic Coupling of the MICE CoolingChannel Magnets and the Magnet Forces for Various MICE OperatingModes

Description: A key issue in the construction of the MICE cooling channel is the magnetic forces between various elements in the cooling channel and the detector magnets. This report describes how the MICE cooling channel magnets are hooked to together so that the longitudinal magnetic forces within the cooling channel can be effectively connected to the base of the experiment. This report presents a magnetic force and stress analysis for the MICE cooling channel magnets, even when longitudinal magnetic forces as large as 700 kN (70 tons) are applied to the vacuum vessel of various magnets within the MICE channel. This report also shows that the detector magnets can be effectively separated from the central MICE cooling channel magnets without damage to either type of magnet component.
Date: August 20, 2006
Creator: Yang, Stephanie Q.; Baynham, D.E.; Fabricatore, Pasquale; Farinon, Stefania; Green, Michael A.; Ivanyushenkov, Yury et al.
Partner: UNT Libraries Government Documents Department

The dynamic inelastic response of delaminated plates

Description: A generalized theory for laminated plates with delaminations is used to consider the influence of inelastic deformations on the dynamic behavior of composite plates with delaminations. The laminate model is based on a generalized displacement formulation implemented at the layer level. The delamination behavior can be modeled using any general interfacial fracture law: however, for the current work a linear model is employed. The interfacial displacement jumps are expressed in an internally consistent fashion in terms of the fundamental unknown interfacial tractions. The current theory imposes no restrictions on the size, location, distribution, or direction of growth of the delaminations. The proposed theory is used to consider the inelastic, dynamic response of delaminated plates in cylindrical bending subjected to a ramp and hold type of loading. The individual layers in the current study are assumed to be either titanium or aluminum. The inelastic response of both materials is modeled using the unified viscoplastic theory of Bodner and Partom. It is shown that the presence of both inelastic behavior and delamination can have a significant influence on the plate response. In particular it is shown that these mechanisms are strongly interactive. This result emphasizes the need to consider both mechanisms simultaneously.
Date: December 1, 1996
Creator: Addessio, F.L. & Williams, T.O.
Partner: UNT Libraries Government Documents Department

Rigid Square Inclusion Embedded within an Epoxy Disk: Asympototic Stress Analysis

Description: The asymptotically singular stress state found at the tip of a rigid, square inclusion embedded within a thin, linear elastic disk has been determined for both uniform cooling and an externally applied pressure. Since these loadings we symmetric, the singular stress field is characterized by a single stress intensity factor, and the applicable calibration relationship has been determined for both fully bonded and unbended inclusions. A lack of interfacial bonding has a profound effect on inclusion-tip stress fields. A large radial compressive stress is generated in front of the inclusion tip when the inclusion is well bonded, whereas a large tensile hoop stress is generated when the inclusion is unbended, and frictionless sliding is allowed. Consequently, an epoxy disk containing an unbended inclusion appears more likely to crack when cooled than a disk containing a fully bonded inclusion. Elastic-plastic calculations show that when the inclusion is unbended, encapsulant yielding has a significant effect on the inclusion-tip stress state. Yielding relieves stress parallel to the interface and greatly reduces the radial compressive stress in front of the inclusion. As a result, the encapsulant is subjected to a nearly uniaxial tensile stress at the inclusion tip. For a typical high-strength epoxy, the calculated yield zone is embedded within the region dominated by the elastic hoop stress singularity. A limited number of tests have been carried out to determine if encapsulant cracking can be induced by cooling a specimen fabricated by molding a square, steel insert within a thin, epoxy disk. Test results are in qualitative agreement with analysis. Cracks developed only in disks with mold-released inserts, and the tendency for cracking increased with inclusion size.
Date: February 2, 1999
Creator: Guess, T.R. & Reedy, E.D.
Partner: UNT Libraries Government Documents Department

Shallow Flaws Under Biaxial Loading Conditions, Part II: Application of a Weibull Stress Analysis of the Cruciform Bend Specimen Using a Hydrostatic Stress Criterion

Description: Cruciform beam fracture mechanics specimensl have been developed in the Heavy Section Steel Technology (HSST) Program at Oak Ridge National Laboratory (ORNL) to introduce a prototypic, far- field, out-of-plane biaxird bending stress component in the test section that approximates the nonlinear biaxial stresses resulting from pressurized-thernxd-shock or pressure-temperature loading of a nuclear reactor pressure vessel (RPV). Matrices of cruciform beam tests were developed to investigate and quantify the effects of temperature, biaxial loading, and specimen size on fracture initiation toughness of two-dimensional (constant depth), shtdlow, surface flaws. Tests were conducted under biaxial load ratios ranging from uniaxial to equibiaxial. These tests demonstrated that biaxial loading can have a pronounced effect on shallow-flaw fracture toughness in the lower transition temperature region for RPV materials. Two and three- parameter Weibull models have been calibrated using a new scheme (developed at the University of Illinois) that maps toughness data from test specimens with distinctly different levels of crack-tip constraint to a small scale yielding (SSY) Weibull stress space. These models, using the new hydrostatic stress criterion in place of the more commonly used maximum principal stress in the kernel of the OW integral definition, have been shown to correlate the experimentally observed biaxiaI effect in cruciform specimens, thereby providing a scaling mechanism between uniaxial and biaxial loading states.
Date: August 1999
Creator: Bass, B. R.; McAfee, W. J. & Williams, P. T.
Partner: UNT Libraries Government Documents Department

Analysis of EB support saddles and forces between modules during assembly.

Description: As the EB Tile Calorimeter is constructed, the support saddles and the modules will be subjected to different forces, stresses, and deflections than when completely assembled. The purpose of this analysis is to examine the forces, stresses, and deflections acting on the support saddles and modules at various stages of assembly.
Date: August 13, 2002
Creator: Guarino, V.
Partner: UNT Libraries Government Documents Department

Analysis of the connections between modules in the EB.

Description: Over the last several years, calculations have been performed to find the forces that are acting between modules and on the support saddles in the EB. This paper examines these forces and calculates the stresses in the connections between modules. In the Tile Calorimeter, the modules are only connected at three points. First, at the inner radius there is a bearing connection to support the force in the phi direction. Second, at the outer radius there is a bearing connection in the phi direction and, finally, there is a bolted connection designed to withstand the radial load. Each of these connections will be examined separately.
Date: August 1, 2002
Creator: Guarino, V.
Partner: UNT Libraries Government Documents Department

Analysis of barrel support saddles and forces between modules during assembly.

Description: As the Barrel Tile Calorimeter is constructed, the support saddles and the modules will be subjected to different forces, stresses, and deflections than when completely assembled. The purpose of this analysis is to examine the forces, stresses, and deflections acting on the support saddles and modules at various stages of assembly. The nominal weight of a barrel module is 20 tons. CERN Document number ATL-LB-EA-0001 'Summary of the Structural Analysis of the Barrel Support Saddles' describes in detail the structural analysis of the saddles and the completed barrel assembly. These calculations followed Eurocode 3. This paper examined several load cases which occur during the assembly of the Barrel. The following are the main conclusions: (1) The assembly is not stable until 18 modules are in place, and only then can the support cradle be removed; (2) The forces between modules are nominal and are far less that the forces in the completed cylinder with 64 modules in place and the cryostat load applied; (3) All of the stresses in the connections between modules are within acceptable limits; and (4) The interface between the cryostat supports and the cryostat move approximately 1.0 mm in the X and Y directions when the load of the cryostat is transferred to the Barrel.
Date: April 23, 2003
Creator: Guarino, V. J. & Physics, High Energy
Partner: UNT Libraries Government Documents Department

Titanium cholla : lightweight, high-strength structures for aerospace applications.

Description: Aerospace designers seek lightweight, high-strength structures to lower launch weight while creating structures that are capable of withstanding launch loadings. Most 'light-weighting' is done through an expensive, time-consuming, iterative method requiring experience and a repeated design/test/redesign sequence until an adequate solution is obtained. Little successful work has been done in the application of generalized 3D optimization due to the difficulty of analytical solutions, the large computational requirements of computerized solutions, and the inability to manufacture many optimized structures with conventional machining processes. The Titanium Cholla LDRD team set out to create generalized 3D optimization routines, a set of analytically optimized 3D structures for testing the solutions, and a method of manufacturing these complex optimized structures. The team developed two new computer optimization solutions: Advanced Topological Optimization (ATO) and FlexFEM, an optimization package utilizing the eXtended Finite Element Method (XFEM) software for stress analysis. The team also developed several new analytically defined classes of optimized structures. Finally, the team developed a 3D capability for the Laser Engineered Net Shaping{trademark} (LENS{reg_sign}) additive manufacturing process including process planning for 3D optimized structures. This report gives individual examples as well as one generalized example showing the optimized solutions and an optimized metal part.
Date: October 1, 2007
Creator: Atwood, Clinton J.; Voth, Thomas Eugene; Taggart, David G. (University of Rhode Island, Kingston, RI); Gill, David Dennis; Robbins, Joshua H. & Dewhurst, Peter (University of Rhode Island, Kingston, RI)
Partner: UNT Libraries Government Documents Department

Influence of large-strain deformation on the microstructure, texture, and mechanical response of tantalum bar

Description: Numerous studies have established the influence of impurities, crystallographic texture, temperature, and strain rate separately or collectively on the constitutive response of annealed tantalum, in particular plate Ta-stock. However, fewer detailed studies have examined the evolution of crystallographic texture and the mechanical response of tantalum bar or rod material following prestraining to large strains {epsilon} > I. In this paper the influence of large plastic prestraining on the microstructure evolution, texture evolution, and mechanical response of high-purity tantalum bar material is presented. Tantalum cylinders annealed at 1200 {degrees}C were quasi-statically upset forged, with intermediate lubrication, to true strains of 0.4, 0.95, and 1.85. Microstructural and textural banding within the starting Ta-bar was characterized in detail. It was found that different oriented bands evolved differently during large-strain forging leading to significant scatter in the mechanical response. Aspects of defect storage, work-hardening response, and texture evolution in Ta-bar as a function of forging strain are discussed.
Date: March 1, 1996
Creator: Gray, G.T. III; Bingert, S.R.; Chen, S.R.; Bingert, J.F. & Wright, S.I.
Partner: UNT Libraries Government Documents Department