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Inelastic Constitutive Properties and shear Localization in Tennessee Marble

Description: Shear bands and faults are ubiquitous features of brittle rock deformation at a variety of length scales. Despite the prevalence of these features, understandhg of their inception remains rudimentary. Laboratory experiments suggest a casual association of localization of deformation (faulting) with peak stress, but more detailed examination reveals that localization can precede or follow the peak. Rudnicki and Rice (1975, hereafter abbreviated as RR) have suggested a the- ory of the inception of localization as a bifurcation or nonuniqueness of the so- lution for homogeneous deformation. They predict a strong dependence of local- ization on deformation state. In particular, they predict that localization can occur prepeak for deformation states near deviatoric pure shear and does not occur until well after peak for axisymmetric compression. This prediction is roughly in ac- cord with the true triaxial experiments of Mogi (1967, 1971). More recently, Ord et al. (1991) and Wwersik et al. (1991) have reported observations of localization prior to peak stress in plane strain experiments. The predictions of RR depend strongly on the constitutive properties of the rock and detailed comparison has been impeded by inadequate knowledge of those properties. Even the idealized constitutive model used by RR requires knowledge of the evolution of the constitutive properties with inelastic deformation that is not readily obtainable from the typical axisymmetric compression test. Although it is conceptually advantageous to consider inelastic deformation at fixed mean stress, the mean stress changes throughout the axisymmetric compression test. In this paper, we present a synthesis of a number of axisymmetric compres- sion tests to extract a detailed implementation of the constitutive framework used by RR. The resulting constitutive relation is then used to -predict the response for plane strain. Conditions for localization of deformation derived by RR are evalu- ated for both plane strain and axisymmetric ...
Date: May 20, 1999
Creator: Holcomb, David J. & Rudnicki, J.W.
Partner: UNT Libraries Government Documents Department

First principles determination of dislocation properties.

Description: This report details the work accomplished on first principles determination of dislocation properties. It contains an introduction and three chapters detailing three major accomplishments. First, we have used first principle calculations to determine the shear strength of an aluminum twin boundary. We find it to be remarkably small ({approx}17 mJ/m{sup 2}). This unexpected result is explained and will likely pertain for many other grain boundaries. Second, we have proven that the conventional explanation for finite grain boundary facets is wrong for a particular aluminum grain boundary. Instead of finite facets being stabilized by grain boundary stress, we find them to originate from kinetic effects. Finally we report on a new application of the Frenkel-Kontorova model to understand reconstructions of (100) type surfaces. In addition to the commonly accepted formation of rectangular dislocation arrays, we find numerous other possible solutions to the model including hexagonal reconstructions and a clock-rotated structure.
Date: December 1, 2003
Creator: Hamilton, John C.
Partner: UNT Libraries Government Documents Department


Description: This work was performed upon request from Dr. Richard Thorpe from NNSA after his review of the LANL report on BSL-3 seismic stability [1]. The authors also reviewed report [1] and concluded, as did Dr. Thorpe, that the stability analysis was inappropriate. There are several reasons for that conclusion: (1) the assumption of a circular failure surface through the combined fill-and-rock foundation does not recognize the geologic structure involved. (2) the assumption of an equivalent static force to an earthquake loading does not represent the multiple cycles of shear loads created by a seismic event that can engender a substantial degradation of shear modulus and shear strength of the soil under the building [2]. (3) there was no credible in-situ strength of the foundation materials (fill and rock mass) available for input into the stability analysis. Following that review, on September 26 the authors made a site visit and held discussions with LANL personnel connected to the BSL-3 building project. No information or evidence was presented to the authors indicating that the static stability of BSL-3 could be an issue. Accordingly, this report focuses on the topic of the BSL-3 site stability under seismic loading.
Date: November 30, 2006
Creator: Heuze, F E & Wagoner, J L
Partner: UNT Libraries Government Documents Department

Interface modeling to predict well casing damage for big hill strategic petroleum reserve.

Description: Oil leaks were found in well casings of Caverns 105 and 109 at the Big Hill Strategic Petroleum Reserve site. According to the field observations, two instances of casing damage occurred at the depth of the interface between the caprock and top of salt. This damage could be caused by interface movement induced by cavern volume closure due to salt creep. A three dimensional finite element model, which allows each cavern to be configured individually, was constructed to investigate shear and vertical displacements across each interface. The model contains interfaces between each lithology and a shear zone to examine the interface behavior in a realistic manner. This analysis results indicate that the casings of Caverns 105 and 109 failed by shear stress that exceeded shear strength due to the horizontal movement of the top of salt relative to the caprock, and tensile stress due to the downward movement of the top of salt from the caprock, respectively. The casings of Caverns 101, 110, 111 and 114, located at the far ends of the field, are predicted to be failed by shear stress in the near future. The casings of inmost Caverns 107 and 108 are predicted to be failed by tensile stress in the near future.
Date: February 1, 2012
Creator: Ehgartner, Brian L. & Park, Byoung Yoon
Partner: UNT Libraries Government Documents Department

Mechanical behavior of ultrahigh strength ultrahigh carbon steel wire and rod

Description: Ultrahigh-carbon steels (UHCSS) can achieve very high strengths in wire or rod form. These high strengths result from the mechanical work introduced during wire and rod processing. These strengths have been observed to increase with carbon content. In wire form, tensile strengths approaching 6000 MPa are predicted for UHCS containing 1. 8%C. In this paper, we will discuss the influence of processing (including rapid transformation during wire patenting) and micros ct- ure on the mechanical behavior of UHCS wire. The tensile properties of as- extruded rods are described as a function of extrusion temperature and composition. For spheroidized steels, yield and ultimate tensile strength are a function of grain size, interparticle spacing and particle size. For pearlitic steels, yield and ultimate strength were found to be functions of colony size, carbide size and plate spacing and orientation. Alloying additions (such as C, Cr, Si, Al and Co) can influence the effect of processing on these microstructural features. For spheroidized steels, fracture was found to be a function of the size of coarse carbides and of composition.
Date: July 22, 1997
Creator: Lesuer, D.R.; Syn, C.K.; Sberby, O.D. & Whittenherger, W.D.
Partner: UNT Libraries Government Documents Department

Numerical modeling of shear band formation in PBX-9501

Description: Adiabatic shear bands in explosives may be a source of ignition and lead to detonation. Three possible mechanisms leading to shear banding are (1) thermal softening, (2) mechanical softening due to microcracking, and (3) quasi-granular constitutive response. The latter two mechanisms can lead to shear band formation in PBXs at nominal strains much smaller than those required for the thermal softening mechanism. The authors study formation of shear bands with models including the latter two mechanisms under unconfined compression. Statistical variation of numerical results is similar to that observed in some experiments. However, the commonly used methods of calibrating constitutive models can be misleading because of effects due to shear band formation. One model currently being used for studies of shear band formation and ignition in PBX 9501 was calibrated in this way and may need re-examination.
Date: December 31, 1998
Creator: Dey, T.N. & Kamm, J.R.
Partner: UNT Libraries Government Documents Department

Correlation of the crack initiation stress with epoxy network topology

Description: Much controversy surrounds the dependence of stress intensity factor of glassy thermosets, epoxies in particular, with crosslink density. One could scan the literature and find references that claim K{sub Ic} increases with crosslink density, decreases with crosslink density, or is independent of crosslink density. The authors feel that two factors contribute to this confusion. First, a typical method for assessing this dependence relies on modifying the crosslink density by changing the precursor epoxy molecular weight. On the other hand, one could change stoichiometry or quench the reaction at intermediate extents of reaction to obtain large changes in crosslink density. However, most studies have not measured the resulting stress intensity factor of these partially cured systems at constant T-T{sub g}, where T{sub g} is the glass transition temperature of the epoxy. Since T{sub g} can change significantly with cure and since fracture processes at the crack tip are dissipative, they must work at constant T-T{sub g} to ensure that the nonlinear viscoelastic mechanisms are fairly compared. In this study, they quenched the reaction of the diglycidyl ether of bisphenol A (DGEBA) and diethanolamine (DEA) at various stages past the gel point and measured the three-point-bend stress intensity factor at a constant T-T{sub g} = {minus}50 C. The trend is clear and significant; increasing crosslink density directly increases the load-to-fail.
Date: March 1, 1997
Creator: Adolf, D.; Weeks, T. & McCoy, J.
Partner: UNT Libraries Government Documents Department

Soldering of Thin Film-Metallized Glass Substrates

Description: The ability to produce reliable electrical and structural interconnections between glass and metals by soldering was investigated. Soldering generally requires premetallization of the glass. As a solderable surface finish over soda-lime-silicate glass, two thin films coatings, Cr-Pd-Au and NiCr-Sn, were evaluated. Solder nettability and joint strengths were determined. Test samples were processed with Sn60-Pb40 solder alloy at a reflow temperature of 210 C. Glass-to-cold rolled steel single lap samples yielded an average shear strength of 12 MPa. Solder fill was good. Control of the Au thickness was critical in minimizing the formation of AuSn{sub 4} intermetallic in the joint, with a resulting joint shear strength of 15 MPa. Similar glass-to-glass specimens with the Cr-Pd-Au finish failed at 16.5 MPa. The NiCr-Sn thin film gave even higher shear strengths of 20-22.5 MPa, with failures primarily in the glass.
Date: March 31, 1999
Creator: Hosking, F.M.; Hernandez, C.L. & Glass, S.J.
Partner: UNT Libraries Government Documents Department

Shear flow induced wave couplings in the solar wind

Description: A sheared background flow in a plasma induces coupling between different MHD wave modes, resulting in their mutual transformations with corresponding energy redistributing between the modes. In this way, the energy can be transfered from one wave mode to the other, but energy can also be added to or extracted from the background flow. In the present paper it is investigated whether the wave coupling and energy transfer mechanisms can operate under solar wind conditions. It is shown that this is indeed the case. Hence, the long-period waves observed in the solar wind at r > 0.3 AU might be generated by much faster periodic oscillations in the photosphere of the Sun. Other possible consequences for observable beat phenomena in the wind and the acceleration of the solar wind particles are also discussed.
Date: January 1, 1998
Creator: Poedts, S.; Rogava, A.D. & Mahajan, S.M.
Partner: UNT Libraries Government Documents Department

Analyses of interfacial shear debonding in fiber-reinforced ceramic composites

Description: An important toughening mechanism in fiber-reinforced ceramic composites is pullout of fibers from the matrix during matrix cracking. This relies on mode II (i.e., shear) debonding at the fiber/matrix interface which can be analyzed using either the strength-based or the energy-based criterion. In the strength-based approach, debonding occurs when the maximum interfacial shear stress induced by the applied load reaches the interfacial shear strength, {tau}{sub s}. In the energy-based approach, a mode II crack propagating along the interface is considered, and debonding occurs when the energy release rate due to crack propagation reaches the interface debond energy, {Gamma}{sub 1}. Based on the above two criteria, the applied stress on the fiber to initiate debonding (i.e., the initial debond stress), {sigma}{sub d}, can be derived. The first issue considered in the present study is the relation between {tau}{sub s} and {Gamma}{sub 1}. Also, for a monolithic ceramic, the tensile strength can be related to its defect size based on the Griffith theory. A question is hence raised as to whether the initial debond stress for fiber pullout in a fiber-reinforced ceramic composite can be related to any defect at the interface.
Date: February 1, 1998
Creator: Hsueh, C.H. & Becher, P.F.
Partner: UNT Libraries Government Documents Department

Effect of firing conditions on thick film microstructure and solder joint strength for low-temperature, co-fired ceramic substrates

Description: Low-temperature, co-fired ceramics (LTCC) are the substrate material-of-choice for a growing number of multi-chip module (MCM) applications. Unlike the longer-standing hybrid microcircuit technology based upon alumina substrates, the manufacturability and reliability of thick film solder joints on LTCC substrates have not been widely studied. An investigation was undertaken to fully characterize solder joints on these substrates. A surface mount test vehicle with Daisy chain electrical connections was designed and built with Dupont{trademark} 951 tape. The Dupont{trademark} 4569 thick film ink (Au76-Pt21-Pd3 wt.%) was used to establish the surface conductor pattern. The conductor pattern was fired onto the LTCC substrate in a matrix of processing conditions that included: (1) double versus triple prints, (2) dielectric window versus no window, and (3) three firing temperatures (800 C, 875 C and 950 C). Sn63-Pb37 solder paste with an RMA flux was screen printed onto the circuit boards. The appropriate packages, which included five sizes of chip capacitors and four sizes of leadless ceramic chip carriers, were placed on the circuit boards. The test vehicles were oven reflowed under a N{sub 2} atmosphere. Nonsoldered pads were removed from the test vehicles and the porosity of their thick film layers was measured using quantitative image analysis in both the transverse and short transverse directions. A significant dependence on firing temperature was recorded for porosity. The double printed substrates without a dielectric window revealed a thick film porosity of 31.2% at 800 C, 26.2% at 875 C and 20.4% at 950 C. In contrast, the thick film porosity of the triple printed substrates with a dielectric window is 24.1% at 800 C, 23.2% at 875 C and 17.6% at 950 C. These observations were compared with the shear strength of the as-fabricated chip capacitor solder joints to determine the effect of firing conditions on solder joint ...
Date: January 4, 2000
Creator: Hernandez, C.L.; Vianco, P.T. & Rejent, J.A.
Partner: UNT Libraries Government Documents Department

Structure-Processing-Property Relationships at the Fiber-Matrix Interface in Electron-Beam Cured Composite Materials

Description: The objective of this project was to characterize the properties of the resin and the fiber- resin interface in electron beam cured materials by evaluating several structural and processing parameters. The Oak Ridge National Laboratory (ORNL) has recently determined that the interlaminar shear strength properties of electron beam cured composites were 19-28% lower than for autoclave cured composites. Low interlaminar shear strength is widely acknowledged as the key barrier to the successfid acceptance and implementation of electron beam cured composites in industry. In this project we found that simple resin modification and process improvements are unlikely to substantially improve the interlaminar shear strength properties of electron beam cured composites. However, sizings and coatings were shown to improve these properties and there appears to be significant potential for further improvement. In this work we determined that the application of epoxy-based, electron beam compatible sizings or coatings onto surface- treated, unsized carbon fibers improved the composite interlaminar shear strength by as much as 55% compared to composites fabricated from surface-treated, unsized carbon fibers and 11 YO compared to composites made from surface-treated, GP sized carbon fibers. This work has identified many promising pathways for increasing the interlaminar shear strength of electron beam cured composites. As a result of these promising developments we have recently submitted a U.S. Department of Energy-Energy Research (DOE-ER) sponsored Laboratory Technical Research-Cooperative Research and Development Agreement (LTR- CRADA) proposal entitled, "Interracial Properties of Electron Beam Cured Composites", to continue this work. If funded, ORNL will lead a 3-year, $2.6 million effort involving eight industrial partners, NASA-Langley, and the U.S. Air Force. The principal objective of this CRADA is to significantly improve the interracial properties of carbon-fiber-reinforced composites beyond the current state-of-the art electron beam cured composites for use in several DOE, DoD, and industrial applications. In addition, several ...
Date: November 1, 1998
Creator: Janke, C.J.
Partner: UNT Libraries Government Documents Department

Interfacial Properties of Electron Beam Cured Composites

Description: The objectives of the CRADA are to: Confirm that fiber-resin adhesion is responsible for the observed poor shear properties; Determine the mechanism(s) responsible for poor adhesion between carbon fibers and epoxy resins after e-beam curing; Develop and evaluate resin systems and fiber treatments to improve the properties of e-beam cured, carbon-fiber-reinforced composites; and Develop refined methods for processing e-beam cured, carbon-fiber-reinforced composites.
Date: December 30, 1999
Creator: Eberle, C.C.
Partner: UNT Libraries Government Documents Department

Machining and grinding: High rate deformation in practice

Description: Machining and grinding are well-established material-working operations involving highly non-uniform deformation and failure processes. A typical machining operation is characterized by uncertain boundary conditions (e.g.,surface interactions), three-dimensional stress states, large strains, high strain rates, non-uniform temperatures, highly localized deformations, and failure by both nominally ductile and brittle mechanisms. While machining and grinding are thought to be dominated by empiricism, even a cursory inspection leads one to the conclusion that this results more from necessity arising out of the complicated and highly interdisciplinary nature of the processes than from the lack thereof. With these conditions in mind, the purpose of this paper is to outline the current understanding of strain rate effects in metals.
Date: April 1, 1993
Creator: Follansbee, P. S.
Partner: UNT Libraries Government Documents Department

Matrix-dominated performance of thick-section fiber composites for flywheel applications

Description: An Achilles heel for the performance of thick-section, cylindrical fiber composite flywheels is the poor interlaminar properties of the material. Methods that have been used to minimize or eliminate radial tensile stresses include prestressing concentric cylinders and mass loading. There can also be significant interlaminar shear stresses at the edges of mass-loaded flywheels and in flywheels for high-power density applications where abrupt braking results in high torque levels. To specify adequate safety factors for thick-section flywheels used in these applications, the failure envelope and fatigue behavior under combined interlaminar stresses are required. Using a hollow cylindrical specimen, which was subjected to combined axial compression and torsion, results for fatigue and failure were generated for several flywheel material systems. Interlaminar compression resulted in significant enhancements to the interlaminar shear strength and results were compared to the predictions of proposed three-dimensional composite failure models. The interlaminar shear fatigue behavior of a carbodepoxy system was also studied and compression was found to greatly enhance fatigue life. The results demonstrate that radial compression stresses can yield improvements in the interlaminar shear strength and fatigue lifetimes of composite flywheel rotors.
Date: January 17, 2001
Creator: DeTeresa, S J; Allison, L M; Freeman, D C & Groves, S E
Partner: UNT Libraries Government Documents Department

Measurement of Shear Strength in BCC Materials Subjected to Moderate Pressures

Description: An experimental procedure is reported to perform shear tests on specimens held under moderately high hydrostatic pressures (on the order of 10 GPa). The mechanical behavior of materials subjected to such pressures, varies substantially from that observed at atmospheric pressure or even pressures typically attained during industrial processing. These differences must be incorporated into models such as the Steinberg-Guinan hardening model or discrete dislocation dynamics simulations. The goal of the proposed research is to develop and implement testing procedures that experimentally determine pressure-dependent dislocation mobilities in oriented single crystals of the BCC transition metals. These experiments will provide calibration data for models of materials subjected to extreme pressures and will assist in model validation. This paper reports the development of the experimental procedures. A thin foil of polycrystalline Ta was used to perform the initial experiments under hydrostatic pressures ranging from 2.1 to 4.2 GPa. Both yielding and hardening behavior are observed to be sensitive to the imposed pressure.
Date: February 17, 2004
Creator: Bonner, B; Leblanc, M; Lassila, D; Field, D & Escobedo, J
Partner: UNT Libraries Government Documents Department

Laboratory Measurements of Velocity and Attenuation in Sediments

Description: Laboratory measurements are required to establish relationships between the physical properties of unconsolidated sediments and P- and S-wave propagation through them. Previous work has either focused on measurements of compressional wave properties at depths greater than 500 m for oil industry applications or on measurements of dynamic shear properties at pressures corresponding to depths of less than 50 m for geotechnical applications. Therefore, the effects of lithology, fluid saturation, and compaction on impedance and P- and S-wave velocities of shallow soils are largely unknown. We describe two state-of-the-art laboratory experiments. One setup allows us to measure ultrasonic P-wave velocities at very low pressures in unconsolidated sediments (up to 0.1 MPa). The other experiment allows P- and S-wave velocity measurements at low to medium pressures (up to 20 MPa). We summarize the main velocity and attenuation results on sands and sand - clay mixtures under partially saturated and fully saturated conditions in two ranges of pressures (0 - 0.1 MPa and 0.1 - 20 MPa) representative of the top few meters and the top 1 km, respectively. Under hydrostatic pressures of 0.1 to 20 MPa, our measurements demonstrate a P- and S-wave velocity-dependence in dry sands around a fourth root (0.23 -0.26) with the pressure dependence for S-waves being slightly lower. The P- velocity-dependence in wet sands lies around 0.4. The Vp-Vs and the Qp-Qs ratios together can be useful tools to distinguish between different lithologies and between pressure and saturation effects. These experimental velocities at the frequency of measurement (200 kHz) are slightly higher that Gassmann's static result. For low pressures under uniaxial stress, Vp and Vs were a few hundred meters per second with velocities showing a strong dependence on packing, clay content, and microstructure. We provide a typical shallow soil scenario in a clean sand environment and reconstruct ...
Date: June 8, 2004
Creator: Zimmer, M A; Berge, P A; Bonner, B P & Prasad, M
Partner: UNT Libraries Government Documents Department

A Novel Mechanical Method to Measure Shear Strength in Specimens Under Pressure

Description: A new experimental apparatus has been developed for performing shear tests on specimens held under moderately high hydrostatic pressures (on the order of 4 GPa). This testing procedure experimentally determines the pressure-dependent shear strength of thin foil specimens. The experiments provide calibration data for models of materials subjected to extreme pressures such as the Steinberg-Guinan hardening model and can assist in model validation for discrete dislocation dynamics simulations, among others. This paper reports the development of the experimental procedures and the results of initial experiments on thin foils of polycrystalline Ta performed under hydrostatic pressures ranging from 1 to 4 GPa. Both yielding and hardening behavior of Ta are observed to be sensitive to the imposed pressure.
Date: April 11, 2006
Creator: Escobedo, J P; Field, D; Lassila, D & Leblanc, M
Partner: UNT Libraries Government Documents Department

The Strength of Single Crystal Copper under Uniaxial Shock Compression at Mbar pressures

Description: In situ x-ray diffraction has been used to measure the shear strain (and thus strength) of single crystal copper shocked to Mbar pressures along the [001] and [111] axes. These direct shear strain measurements indicate shear strengths at these ultra-high strain rates (of order 10{sup 9} s{sup -1}) of a few GPa, which are both broadly in agreement with the extrapolation of lower strain-rate data and with non-equilibrium molecular dynamics simulations.
Date: May 21, 2009
Creator: Murphy, W; Higginbotham, A; Kimminau, G; Barbrel, B; Bringa, E; Hawreliak, J et al.
Partner: UNT Libraries Government Documents Department

The Mechanical Properties of Stripa Granite

Description: The mechanical properties of Stripa granite are presented as determined from small (laboratory size), oven-dried specimens, The properties determined include Young's modulus, Poisson's ratio, unaxial compressive fracture stress, and the expansion coefficient, all as a function of temperature, In addition the Brazilian tensile fracture stress, residual shear strength as a function of a normal stress and the rock's anisotropy ratios are presented, Finally ultrasonic determinations at 1 MHz of the rock's dilatational wave velocity are given and the deduced Young's modulus is compared with the static value for room temperature. This report is one of a series documenting the results of the Swedish-American cooperative research program in which the cooperating scientists explore the geological, geophysical, hydrological, geochemical, and structural effects anticipated from the use of a large crystalline rock mass as a geologic repository for nuclear waste.
Date: August 1, 1978
Creator: Swan, G.
Partner: UNT Libraries Government Documents Department

Analysis of Injection-Induced Micro-Earthquakes in a Geothermal Steam Reservoir, The Geysers Geothermal Field, California

Description: In this study we analyze relative contributions to the cause and mechanism of injection-induced micro-earthquakes (MEQs) at The Geysers geothermal field, California. We estimated the potential for inducing seismicity by coupled thermal-hydrological-mechanical analysis of the geothermal steam production and cold water injection to calculate changes in stress (in time and space) and investigated if those changes could induce a rock mechanical failure and associated MEQs. An important aspect of the analysis is the concept of a rock mass that is critically stressed for shear failure. This means that shear stress in the region is near the rock-mass frictional strength, and therefore very small perturbations of the stress field can trigger an MEQ. Our analysis shows that the most important cause for injection-induced MEQs at The Geysers is cooling and associated thermal-elastic shrinkage of the rock around the injected fluid that changes the stress state in such a way that mechanical failure and seismicity can be induced. Specifically, the cooling shrinkage results in unloading and associated loss of shear strength in critically shear-stressed fractures, which are then reactivated. Thus, our analysis shows that cooling-induced shear slip along fractures is the dominant mechanism of injection-induced MEQs at The Geysers.
Date: May 15, 2008
Creator: Rutqvist, Jonny; Rutqvist, J. & Oldenburg, C.M.
Partner: UNT Libraries Government Documents Department

Finite element analyses for seismic shear wall international standard problem

Description: Two identical reinforced concrete (RC) shear walls, which consist of web, flanges and massive top and bottom slabs, were tested up to ultimate failure under earthquake motions at the Nuclear Power Engineering Corporation`s (NUPEC) Tadotsu Engineering Laboratory, Japan. NUPEC provided the dynamic test results to the OECD (Organization for Economic Cooperation and Development), Nuclear Energy Agency (NEA) for use as an International Standard Problem (ISP). The shear walls were intended to be part of a typical reactor building. One of the major objectives of the Seismic Shear Wall ISP (SSWISP) was to evaluate various seismic analysis methods for concrete structures used for design and seismic margin assessment. It also offered a unique opportunity to assess the state-of-the-art in nonlinear dynamic analysis of reinforced concrete shear wall structures under severe earthquake loadings. As a participant of the SSWISP workshops, Brookhaven National Laboratory (BNL) performed finite element analyses under the sponsorship of the U.S. Nuclear Regulatory Commission (USNRC). Three types of analysis were performed, i.e., monotonic static (push-over), cyclic static and dynamic analyses. Additional monotonic static analyses were performed by two consultants, F. Vecchio of the University of Toronto (UT) and F. Filippou of the University of California at Berkeley (UCB). The analysis results by BNL and the consultants were presented during the second workshop in Yokohama, Japan in 1996. A total of 55 analyses were presented during the workshop by 30 participants from 11 different countries. The major findings on the presented analysis methods, as well as engineering insights regarding the applicability and reliability of the FEM codes are described in detail in this report. 16 refs., 60 figs., 16 tabs.
Date: April 1998
Creator: Park, Y. J. & Hofmayer, C. H.
Partner: UNT Libraries Government Documents Department