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Impact Tests for Woods

Description: Although it is well known that the strength of wood depends greatly upon the time the wood is under the load, little consideration has been given to this fact in testing materials for airplanes. Here, results are given of impact tests on clear, straight grained spruce. Transverse tests were conducted for comparison. Both Izod and Charpy impact tests were conducted. Results are given primarily in tabular and graphical form.
Date: February 1922
Partner: UNT Libraries Government Documents Department

Micromechanics of spall and damage in tantalum

Description: The authors conducted a series of plate impact experiments using an 80-mm launcher to study dynamic void initiation, linkup, and spall in tantalum. The tests ranged in peak shock pressures so that the effect of peak pressure on the transition from void initiation, incipient spall, and full spall could be studied. Wave profiles were measured using a velocity interferometry system (VISAR), and targets were recovered using {open_quotes}soft{close_quotes} recovery techniques. The authors utilized scanning electron microscopy, metallographic cross-sections, and plateau etching techniques to obtain quantitative information concerning damage evolution in tantalum under spall conditions. The data (wave profiles and micrographs) are analyzed in terms of a new theory and model of dynamic damage cluster growth.
Date: May 1, 1996
Creator: Zurek, A.K.; Thissell, W.R.; Johnson, J.N.; Tonks, D.L. & Hixson, R.
Partner: UNT Libraries Government Documents Department

Spall Strength Measurements of Concrete for Varying Aggregate Sizes

Description: Controlled impact experiments have been performed to determine the spall strength of four different concrete compositions. The four concrete compositions are identified as, `SAC-5, CSPC', ("3/4") large, and ("3/8") small, Aggregate. They differ primarily in aggregate size but with average densities varying by less than five percent. Wave profiles from sixteen experiments, with shock amplitudes of 0.07 to 0.55 GPa, concentrate primarily within the elastic regime. Free-surface particle velocity measurements indicate consistent pullback signals in the release profiles, denoting average span strength of approximately 40 MPa. It is the purpose of this paper to present spall measurements under uniaxial strain loading. Notwithstanding considerable wave structure that is a unique characteristic to the heterogeneous nature of the scaled concrete, the spall amplitudes appear reproducible and consistent over the pressure range reported in this study.
Date: May 5, 1999
Creator: Chhabildas, Lalit C.; Kipp, Marlin E.; Reinhart, William D. & Wilson, Leonard T.
Partner: UNT Libraries Government Documents Department

Drop Tests of 325 Pound 6M Specification Packages

Description: Testing of 6M specification packages, performed in response to concerns over the integrity of the clamp-ring closure, showed that the clamp-ring was unable to retain the top in thirty foot drop tests of packages having the maximum allowed weight (290 kg or 640 lb). To determine if the clamp-ring closure was adequate for packages with lower contents weight, a series of tests were performed on packages weighing 147 kg (325 lb) at a range of impact angles. The results showed that the standard clamp-ring closure was unable to retain the top in tests of standard 6M packages weighing 147 kg (325 lb). A test employing a plywood disk enhanced closure with impact at 6.5 degrees retained its top successfully.
Date: April 30, 2004
Creator: SMITH, AC
Partner: UNT Libraries Government Documents Department

Drop Tests of the Closure Ring for the 9975 Package

Description: The drop tests of the closure ring for 9975 packages, described here, were performed to answer questions raised by the regulatory authority as a result of deformation of the closure ring and drum rim observed during drop tests conducted in September 1998.
Date: September 29, 1999
Creator: Smith, A. C.
Partner: UNT Libraries Government Documents Department

Evaluation of impact tests of solid steel billet onto concrete pads, and application to generic ISFSI storage cask for tipover and side drop

Description: Twelve tests were performed at LLNL to assess loading conditions on a spent fuel casts for side drops, end drops and tipover events. The tests were performed with a 1/3-scale model concrete pad to benchmark the structural analysis code DYNA3D. The side drop and tipover test results are discussed in this report. The billet and test pad were modified with DYNA3D using material properties and techniques used in earlier tests. The peak or maximum deceleration test results were compared to the simulated analytical results. It was concluded that an analytical model based on DYNA3D code and has been adequately benchmarked for this type of application. A generic or represented cask was modified with the DYNA3D code and evaluated for ISFSI side drop and tipover events. The analytical method can be applied to similar casks to estimate impact loads on storage casks resulting from low-velocity side or tip impacts onto concrete storage pads.
Date: May 1, 1997
Creator: Witte, M.C.; Chen, T.F.; Murty, S.S.; Tang, D.T.; Mok, G.C.; Fischer, L.E. et al.
Partner: UNT Libraries Government Documents Department

Equation of State Measurements of Materials Using a Three-Stage Gun to Impact Velocities of 11km/s

Description: Understanding high pressure behavior of homogeneous as well as heterogeneous materials is necessary in order to address the physical processes associated with hypervelocity impact events related to space science applications including orbital debris impact and impact lethality. At very high impact velocities, material properties will be subjugated to phase-changes, such as melting and vaporization. These phase states cannot be obtained through conventional gun technology. These processes need to be represented accurately in hydrodynamic codes to allow credible computational analysis of impact events resulting from hypervelocity impact. In this paper, techniques that are being developed and implemented to obtain the needed shock loading parameters (Hugoniot states) for material characterization studies, namely shock velocity and particle velocity, will be described at impact velocities up to 11 km/s. What is new in this report is that these techniques are being implemented for use at engagement velocities never before attained utilizing two-stage light-gas gun technology.
Date: September 26, 2000
Partner: UNT Libraries Government Documents Department

DropTests of 325 Pound 6M Packages

Description: There are many factors which affect the performance of a drum closure during drop tests. Important test conditions are: weight of package, height of drop, and angle of impact. Structural characteristics of the package determine its ability to withstand the test conditions imposed. These characteristics include: package diameter, shell material and thickness, strength of internal fill material (e.g., fiberboard), and configuration of closure (clamp-ring, bolted flange, etc.). For the clamp-ring closure configuration a study of published drop test results has shown that packages having a weight ratio of less than 50 per cent were typically able to retain their lids in hypothetical accident condition, 30-ft drop tests. Those having weight ratios greater than 50 per cent typically failed. Prior testing over the integrity of the clamp-ring closure, consistently demonstrated that the clamp-ring is unable to retain the drum lid in thirty foot drop tests of packages containing the maximum allowed weight (640 lb), which confirms the previous studies. To determine if the clamp-ring closure is adequate for packages with lower weight contents, a series of tests were performed on packages weighing around 325 lb (i.e., a typical shipping weight for DOE packages) at a range of impact angles as detailed in this report. The test results consistently demonstrated that the standard clamp-ring closure is unable to retain the drum lid of standard 6M packages weighing 325 lb.
Date: January 30, 2004
Creator: Gelder, L. A.
Partner: UNT Libraries Government Documents Department

FAA debris mitigation phase I impact test report

Description: The goal of the study is the accurate prediction of the effect of uncontained engine debris on aircraft structures. This will provide airframe engineers the information required to design for damage mitigation and improved safety. The basis for predictive simulation tools lies in the experimental data, which motivates the initial development and application of codes that can adequately describe past experiments. This in turn validates the predictive capability of the codes to simulate future experiments.
Date: March 8, 1999
Creator: Couch, R
Partner: UNT Libraries Government Documents Department

Drop Tests for the 6M Specification Package Closure Investigation

Description: Results of tests of drum-type RAM packages employing conventional clamp-ring closures have caused concern over the DOT 6M Specification Package. To clarify these issues, a series of tests were performed to determine the response of the clamp-ring closure to the regulatory Hypothetical Accident Condition (9m) drop tests, for packages at maximum allowable weight. Three enhanced closure designs were also tested: the Clamshell, plywood disk reinforcement, and J-Clip. The results of the tests showed that the standard closure was unable to retain the top for both Center-of-Gravity-Over-Corner and Shallow Angle cases, for the standard package, at its maximum allowed weight. Similar results were found for packages dropped from a reduced height. The Clamshell design provided the best performance of the enhanced closures. It was concluded that the closure ring design employed on the 6M is inadequate to retain the top during the regulatory test sequence, for packages at the maximum allowed weight. For large heavy packages, the Center-of-Gravity- Over-Corner case is more challenging than the Shallow Angle case. The Clamshell design securely retained the top for all HAC test cases, and prevented formation of any opening which could compromise fire test performance.
Date: April 30, 2004
Creator: SMITH, AC
Partner: UNT Libraries Government Documents Department

Experimental measurements of shock properties of stishovite

Description: We have synthesized, characterized and performed Hugoniot measurements on monolithic samples of stishovite, a high pressure polymorph of silica. Synthesis was accomplished in a multianvil press with pyrophyllite gaskets and carbon heaters. The samples had densities ranging from 3.80 to 4.07, corresponding to stishovite volume fractions of 0.7 to 0.87, a range confirmed by NMR analysis. They had no significant impurities except less than 1% carbon. Samples {approximately} 1 mm thick and 3 mm diameter were tested in reverse- and forward-ballistics modes on a two-stage light gas gun, using velocity interferometry diagnostics. Impact velocities ranged from 4.0 to 6.5 km/sec. Hugoniot stresses for the four successful tests ranged from 65 to 225GPa. At higher stresses significant uncertainties arise due to impact tilt/nonplanariy issues. Results are consistent with earlier predictions of the stishovite Hugoniot based on quartz-centered Hugoniot data, static-compression (diamond-anvil cell) data and hydrostatic multianvil cell data. Release behavior appears to be frozen. These results are remarkable in view of the small size of the samples used.
Date: October 1, 1995
Creator: Furnish, M.D. & Ito, E.
Partner: UNT Libraries Government Documents Department

A study of the effect of grain size on the ballistic performance of silicon carbide

Description: The depth of penetration method was used to ballistically evaluate the performance of silicon carbide as a function of grain size. The hot-pressed silicon carbide was backed by 4340 steel Rc = 35 and impacted by tungsten heavy metal projectiles of L/D = 4 at velocities of 1.6 and 1/75 km/s. The hot-pressed silicon carbide was also compared with reaction-sintered silicon carbide of identical thickness in the current study. Results are compared with data previously reported by others.
Date: March 1, 1995
Creator: Cline, C. F.
Partner: UNT Libraries Government Documents Department

Elastic shock response and spall strength of concrete

Description: Impact experiments have been performed to obtain shock compression, release response, and spall strength of two scaled concrete formulations. Wave profiles from a suite of ten experiments, with shock amplitudes of 0.08 to 0.55 GPa, focus primarily on the elastic regime. Despite considerable wave structure that develops at the shock transits these heterogeneous targets, consistent pullback signals were identified in the release profiles, indicating a spall strength of about 30 MPa. Explicit modeling of the concrete aggregate structure in numerical simulations provides insight into the particle velocity records.
Date: August 1, 1997
Creator: Kipp, M.E.; Chhabildas, L.C. & Reinhart, W.D.
Partner: UNT Libraries Government Documents Department

Segmented Aluminum Honeycomb Characteristics in T-Direction, Dynamic Crush Environments

Description: Thirteen segmented aluminum honeycomb samples (5 in. diameter and 1.5 in. height) have been crushed in an experimental configuration that uses a drop table impact machine. The 38.0 pcf bulk density samples are a unique segmented geometry that allows the samples to be crushed while maintaining a constant cross-sectional area. A crush weight of 175 lb was used to determine the rate sensitivity of the honeycomb's highest strength orientation, T-direction, in a dynamic environment of {approx}50 fps impact velocity. Experiments were conducted for two honeycomb manufacturers and at two temperatures, ambient and +165 F. Independent measurements of the crush force were made with a custom load cell and a force derived from acceleration measurements on the drop table using the Sum of Weighted Accelerations Technique with a Calibrated Force (SWAT-CAL). Normalized stress-strain curves for all thirteen experiments are included and have excellent repeatability. These data are strictly valid for material characteristics in the T orientation because the cross-sectional area of the honeycomb did not change during the crush. The dynamic crush data have a consistent increase in crush strength of {approximately}7--19% as compared to quasi-static data and suggest that dynamic performance may be inferred from static tests. An uncertainty analysis estimates the error in these data is {+-} 11%.
Date: August 23, 2000
Partner: UNT Libraries Government Documents Department

Numerical simulations of glass impacts using smooth particle hydrodynamics

Description: As part of a program to develop advanced hydrocode design tools, we have implemented a brittle fracture model for glass into the SPHINX smooth particle hydrodynamics code. We have evaluated this model and the code by predicting data from one-dimensional flyer plate impacts into glass. Since fractured glass properties, which are needed in the model, are not available, we did sensitivity studies of these properties, as well as sensitivity studies to determine the number of particles needed in the calculations. The numerical results are in good agreement with the data.
Date: July 1, 1995
Creator: Mandell, D.A. & Wingate, C.A.
Partner: UNT Libraries Government Documents Department

Final Report: Drop Testing of Aged Stems on the SP981 Reservoir

Description: Free fall drop testing of unloaded SP981 reservoirs was conducted by Savannah River Technology Center in the Materials Test Facility. The testing consisted of dropping eight aged and two unaged reservoirs on their stems at impact angles of 88 degrees and 70 degrees from heights of approximately 4 and 6 foot above a hardened steel surface.
Date: August 11, 1999
Creator: White, M.B.
Partner: UNT Libraries Government Documents Department

Experimental Bench Mark Data for ALEGRA Code Validations

Description: In this study experiments of increasing complexity have been conducted to provide a data base for validating features of the Arbitrary Lagrangian Eulerian Grid for Research Applications (ALEGRA) code over a broad range of strain rates with overlapping diagnostics that encompass multiple responses. This range encompasses strain rates characteristic of shock-wave propagation (10<sup>7</sup>/s) and those chameteristics of structural response (10<sup>2</sup>/s). The tests matrix consists of two experimental series; the first being a simple system test with diagnostics that capture features relevant to both the high strain-rate hydrodynamic response and the low strain-rate structural response of the target. The second series of experiments increased the complexity of tests with the addition of foam to the original simple series. The input conditions are extremely well defined. Velocity interferometers are used to record the high strain-rate response, while the low strain-rate data were collected using strain, carbon and PVDF gauges.
Date: June 23, 1999
Creator: Chhabildas, L. C.; Kipp, M. E.; Konrad, C. H.; Mann, G. A.; Mosher, D. A.; Peery, J. S. et al.
Partner: UNT Libraries Government Documents Department

Hyperveolcity impacts on aluminum from 6 to 11 km/s for hydrocode benchmarking.

Description: A systematic computational and experimental study is presented on impact generated debris resulting from record-high impact speeds recently achieved on the Sandia three-stage light-gas gun. In these experiments, a target plate of aluminum is impacted by a titanium-alloy flyer plate at speeds ranging from 6.5 to 11 km/s, producing pressures from 1 Mb to over 2.3 Mb, and temperatures as high as 15000 K (&gt;1 eV). The aluminum plate is totally melted at stresses above 1.6 Mb. Upon release, the thermodynamic release isentropes will interact with the vapor dome. The amount of vapor generated in the debris cloud will depend on many factors such as the thickness of the aluminum plate, super-cooling, vaporization kinetics, the distance, and therefore time, over which the impact-generated debris is allowed to expand. To characterize the debris cloud, the velocity history produced by stagnation of the aluminum expansion products against a witness plate is measured using velocity interferometry. X-ray measurements of the debris cloud are also recorded prior to stagnation against an aluminum witness plate. Both radiographs and witness-plate velocity measurements suggest that the vaporization process is both time-dependent and heterogeneous when the material is released from shocked states around 230 GPa. Experiments suggest that the threshold for vaporization kinetics in aluminum should become significant when expanded from shocked states over 230 GPa. Numerical simulations are conducted to compare the measured x-ray radiographs of the debris cloud and the time-resolved experimental interferometer record with calculational results using the 3-D hydrodynamic wavecode, CTH. Results of these experiments and calculations are discussed in this paper.
Date: April 1, 2003
Creator: Saul, W. Venner; Reinhart, William Dodd; Thornhill, Tom Finley, III; Lawrence, Raymond Jeffery, Jr.; Chhabildas, Lalit Chandra; Bessette, Gregory Carl et al.
Partner: UNT Libraries Government Documents Department

Evaluation of low-velocity impact tests of solid steel billet onto concrete pads, and application to generic ISFSI storage cask for tipover and side drop

Description: Spent Fuel Storage Casks intended for use at Independent Spent Fuel Storage Installations (ISFSIS) typically are evaluated during the application and review process for low-energy impacts representative of possible handling accidents including tipover events. In the past, the analyses involved in these evaluations have assumed that the casks dropped or tipped onto an unyielding surface, a conservative and simplifying assumption. Since 10 CFR Part 72`, the regulation imposed by the Nuclear Regulatory Commission (NRC), does not require this assumption, applicants are currently seeking a more realistic model for the analyses and are using analytical models which predict the effect of a cask dropping onto a reinforced concrete pad, including energy absorbing aspects such as cracking and flexure. In order to develop data suitable for benchmarking these analyses, the NRC has conducted several series of drop-test studies. The tests described in this report were primarily intended to determine the response characteristics of concrete pads during tipover and side impacts of a solid steel billet onto the pads. This series of tests is fourth in a program of tests funded by the NRC; all four series of tests address issues of impact involving spent fuel storage casks. The first series was performed in March 1993 by Sandia National Laboratories (SNL) and involved five end-drops of a billet, nearly identical to the one used in the present series, onto a variety of surfaces from a height of 18 inches. The second series of tests was performed between July and October 1993, and involved four end- drops of a near-full-scale empty Excellox 3A cask onto a full-scale concrete pad and foundation, or onto an essentially unyielding surface, from heights ranging from 18 inches to 60 inches, and was conducted by the British Nuclear Fuels Limited in Winfrith, England. (Two of the drops in the …
Date: March 1, 1997
Creator: Witte, M. C.; Chen, T.F.; Mok, G.C.; Murty, S.S. & Fischer, L.E.
Partner: UNT Libraries Government Documents Department
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