The utilization of pressure stabilized structural elements in tentage support structures requires techniques for the design of such elements. A theory has been developed and reported previously for carrying out such a design of pressure stabilized beams. In this report an experimental investigation of the behavior of pressure stabilized beams under load is described and the experimental results are correlated with predictions from the theory. This correlation establishes the validity of the...

Topics: DTIC Archive, Steeves, Earl C, ARMY NATICK LABS MA, *BEAMS(STRUCTURAL), *INFLATABLE STRUCTURES,...

This report describes the mathematical model and the solution process which form the basis of the computer program SINGER. The function of SINGER is to predict the behavior of plane skeletal reinforced concrete structures in their environments. Of primary interest is the transient nonlinear response including element failures and structural collapse. The structure is represented by a discrete model composed of line elements (models of partial joint releases). The line elements admit geometric...

Topics: DTIC Archive, Holzer, S M, VIRGINIA POLYTECHNIC INST AND STATE UNIV BLACKSBURG DEPT OF CIVIL AND...

MS(STRUCTURAL), PRESSURE VESSELS, RIVETED JOINTS, FASTENERS*STRESSESThe analysis manual is issued to provide a general purpose structural analysis capability and to serve as a source of data. It represents a collection of techniques from a wide variety of industry sources, textbooks, periodicals, and government agencies. Attempts have been made where applicable to give appropriate recognition to each source. Based on the evaluation of the stress analysis and design techniques and procedures...

Topics: DTIC Archive, Maddux, Gene E, TECHNOLOGY INC DAYTON OH, *STRUCTURAL PROPERTIES, *HANDBOOKS,...

Described is an experimental technique for providing long-duration pulses which can be applied to a part or all of a simple structure such as a beam, plate or cylinder. The technique employs essentially the familiar shock tube except that the detonation front of a gaseous explosive provides the shock wave. Many pulse shapes can be produced by placing in the tube and against the target, layers of different materials such as styrofoam, polyurethane, and Mylar, and by sending the...

Topics: DTIC Archive, Florence, A L, STANFORD RESEARCH INST MENLO PARK CA POULTER LABS, *LOADS(FORCES),...

The analysis of the dynamic response of a vibrating structure in contact with a fluid medium can be interpreted as an added mass effect known as the Fluid Structure Interaction (FSI) problem. This effect is critical in the study of composites for marine applications since the densities of the composites and water are relatively close to one another. In this study, experimental testing was conducted to compare the free vibration response of composite beams in air with those in FSI immersed in...

Topics: DTIC Archive, NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *BEAMS(STRUCTURAL), *VIBRATION, COMPOSITE...

This report documents the design, analysis and open-loop testing of the 12-Meter Truss Active Control Experiment at Wright Laboratory. The objectives of the experiment were to develop a test bed which was representative of the dynamic characteristics of future large space systems and then evaluate the performance of leading active vibration control approaches applied to the test bed. The experimental hardware consisted of a 12-meter-long aluminum truss beam equipped with eight linear momentum...

Topics: DTIC Archive, Gordon, Robert W, WRIGHT LAB WRIGHT-PATTERSON AFB OH, *VIBRATION, *SPACECRAFT,...

The goal of this effort is to develop shear-deformable finite elements which can be used to find the natural frequencies of composite beams. The first objective of the study is to derive the mass and stiffness matrices for the elements of interest and incorporate them into computer programs which can be used to estimate the natural frequencies of composite beams. Composite beams of interest include sandwich beams and those of fiber-reinforced laminated construction. Elements based on the beam...

Topics: DTIC Archive, Whitehouse, Stephen R, AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH, *COMPUTER...

The report presents design charts for the selection of cold-formed steel panel and wide-flange beam sections used in structures designed to resist blast loads produced by high-explosive detonations. These steel sections are applicable to the walls, roof, and supporting members (girts, purlins, etc.) of blast-protective acceptor structures in Army Ammunition Plants and other explosive manufacturing and storage facilities. Each design chart consists of plots of steel panel or beam sections versus...

Topics: DTIC Archive, Tseng, George, Weissman, Samuel, Dobbs, Norval, Price, Paul, AMMANN AND WHITNEY NEW...

Bending tests of Douglas-fir and southern pine glulam beams of 2-, 4-, or 6-laminations revealed the following about the accuracy of the three methods for predicting near-minimum bending strengths: (1) The minimum strength ratio (SR) concept, method A, overestimated most of the near-minimum values; (2) No difference could be detected between the minimum SR concept, method B, and the K/G concept. These two methods also overestimated some of the near-minimum values. In addition, the data revealed...

Topics: DTIC Archive, Marx,Catherine M, FOREST PRODUCTS LAB MADISON WI, *BEAMS(STRUCTURAL), *BENDING,...

Analyses were performed for static and dynamic buckling of a continuous fiber embedded in a matrix in order to determine the effects of interfacial debonding and fiber breakage on the critical buckling load and the domain of instability. A beam on elastic foundation model was used for the study. The study showed that a local interfacial debonding between a fiber and a surrounding matrix resulted in an increase of the wavelength of the buckling mode. An increase of the wave length yielded a...

Topics: DTIC Archive, Serttunc, Metin, NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *FIBERS, *MATRIX MATERIALS,...

Two-dimensional continuum modeling and simulations were conducted to predict how the size, quantity, and stiffness of reinforcing particles such as carbon nanotubes (CNTs) affect failure mechanisms at the interface of composite structures. First, the strength model used the finite element method (FEM) on a slender composite beam with step-joint containing reinforcing particles to predict its critical stress-strain behavior at the joint interface under compressive axial load. Next, the fracture...

Topics: DTIC Archive, Griffiths, Robert P, NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *INTERFACES, *COMPOSITE...

The purpose of this thesis is to develop a better model of damping that occurs in structural joints due to coulomb friction when rotational slip occurs in the joints. A one-dimensional, indirect formulation, of the Boundary Element Method(BEM) is developed to calculate the displacement, rotation, moment and shear in beams which obey the assumptions of simple beam theory. This BEM code is then modified to account for friction damping at the joint of two beams due to a relative rotation between...

Topics: DTIC Archive, Leiker, Gregory L, AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF...

The strain dependence and specific damping capacity (SDC) of the damping alloy, Vacrosil-010 (84.5 Fe, 11.3 Cr, 2.4 Mo), was determined using a modified version of the resonant dwell technique. Cantilever beam specimens were annealed for 1 hour at temperatures between 800 C and 1100 C. They were subsequently vibrated at their first three resonant modes ( 0-1000 Hz) at room temperature. The effect on damping capacity of changes in heat treatment were investigated using tensile hysteresis...

Topics: DTIC Archive, O'Toole, Jr, John F, NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *ALLOYS, *DAMPING,...

New interpretations to the results from previously reported air blast-loaded beam tests are derived, based on computations using a modified finite difference large amplitude elastoplastic beam response code which now includes a new strain-rate dependent constitutive model plus associated dynamic material data and revisions to better simulate the physical support conditions, including frictional and rotatory inertia effects.

Topics: DTIC Archive, Huffington,N J , Jr, ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD,...

Partial Contents: Experimental Validation of the Component Synthesis Method for Predicting Vibration of Liquid-Filled Piping; Acoustic Responses of Coupled Fluid-Structure System by Acoustic-Structural Analogy; Fluid-Structure Interaction by the Method of Characteristics; A Solution to the Axisymmetric and One-Dimensional Bulk Cavitation Problem; Dynamic Simulation of Structural Systems with Isolated Nonlinear Components; Experimental and Analytical Investigation of Active Loads Control for...

Topics: DTIC Archive, NAVAL RESEARCH LAB WASHINGTON DC SHOCKAND VIBRATION INFORMATION CENTER, *VIBRATION,...

A systematic sampling of joint lumber was carried out at retail lumber yards over two summers to observe and measure physical and mechanical properties close to point of purchase and use. The study sought to define acceptable performance of the dimension lumber in terms of floor system performance using a composite of current standards. Measured properties of the material were discussed in terms of that tentative criterion. This interim report emphasizes sampling procedures, testing methods,...

Topics: DTIC Archive, Galligan,W L, FOREST PRODUCTS LAB MADISON WI, *STRUCTURAL PROPERTIES, *FLOORS,...

Since longitudinal modes and frequencies provide basic data for dynamic analyses of arbitrary beam-like structures and since closed-form solutions for the modes are generally not feasible to obtain, an approximate method is developed for computing the natural frequencies and the corresponding mode shapes for a variable-section, unconstrained multibranch beam. A lumped mass analogy employing influence coefficients is used to represent the beam. The simultaneous equations of motion for the lumped...

Topics: DTIC Archive, Wingate, Robert T, NATIONAL AERONAUTICS AND SPACE ADMINISTRATION HAMPTON VA LANGLEY...

Topics: DTIC Archive, Lee, G C, LEHIGH UNIV BETHLEHEM PA FRITZ ENGINEERING LAB, *BEAMS(STRUCTURAL), LOAD...

After a discussion of the possible use of the sandwich beam design as a means of incorporating damping into tuned mass dampers, the development of a finite element model for viscoelastic sandwich beam analysis is presented. The requirement for future use of the viscoelastic sandwich beam design in TMDs is to have a method by which the response of a beam with any given dimensions or end conditions can be determined. A survey of previous published research into sandwich beam behavior demonstrates...

Topics: DTIC Archive, Maddox, Richard A., VIRGINIA UNIV CHARLOTTESVILLE SCHOOL OF ENGINEERING AND APPLIED...

Evaluation of 120 glued laminated (glulam) beams provided criteria for improved utilization of lumber in such beams. Objectives were: (1) to determine if lumber grade can be somewhat reduced on the compression side of beams without significantly changing design strength; (2) to establish analytic procedures for incorporating lumber having had its modulus of elasticity (e) determined (E-rated lumber) into glulam beams; and (3) to determine the effect on beam properties of using lumber with...

Topics: DTIC Archive, Moody,Russell C, FOREST PRODUCTS LAB MADISON WIS, *BEAMS(STRUCTURAL), *LUMBER,...

A finite element model of a two-for-one tactical shelter is presented. The model is compatible with the COSMIC*NASTRAN finite element program. Both beam and composite plate elements are used in the model. The geometric properties of the beams are given in tables. The shelter's response to racking loads is calculated for one transverse loading condition on each end of the shelter. Two computer models are used to analyze the response at the personnel door end and seven models for the cargo door...

Topics: DTIC Archive, Johnson, Arthur R, ARMY NATICK RESEARCH AND DEVELOPMENT CENTER MA, *COMPUTER AIDED...

New techniques for explosive demolition of structural steel shapes were developed and evaluated in connection with the examination of current U. S. Army methods of steel cutting with high-explosive charges. The report concludes: (1) both charge width and charge thickness have significant effects on the steel-cutting efficiency of contact explosive charges; (2) the point of charge initiation does not significantly affect the shattering power of contact explosive charges on steel; (3) a 3:1 ratio...

Topics: DTIC Archive, Dennis, James A, ARMY ENGINEER RESEARCH AND DEVELOPMENT LABS FORT BELVOIR VA, *STEEL,...

The current Air Force Nondestructive Pavement Testing (NDPT) method requires a rational method to evaluate pavement layer modulus values. A reasonable step toward the development of such a method is computer analyses of elastic layered systems subjected to dynamic loading. This research adopts the Method of Direct Analysis which uses the impulse-momentum laws and constitutive relations but bypasses the explicit use of differential equations. As a result of the research, two computer programs...

Topics: DTIC Archive, Wang,M C, PENNSYLVANIA STATE UNIV UNIVERSITY PARK DEPT OF CIVIL ENGINEERING,...

The conference was held as scheduled. Abstracts of the presentations appear in a report distributed by the Virginia Polytechnic Institute and State University Sessions included identification and control, analytical methods, impact dynamics, dynamics and control, applications to cables, optimization and computational methods, coupled oscillators, applications to mechanical systems, random vibrations, analytical and symbolic methods, applications to structural elements, multibody dynamics, and...

Topics: DTIC Archive, Nayfeh, A H, VIRGINIA POLYTECHNIC INST AND STATE UNIV BLACKSBURG, *VIBRATION,...

The finite element method is extended to the refined elastic analysis of multilayer beams and shells with no restriction placed upon the ratios of the layer thicknesses and properties. The method is applicable to structures wherein shearing deformations are significant, including sandwich-type structures. Element stiffnesses are based on polynomial displacement models and are applicable to the linear elastic analysis of beams and thin, axisymmetric shells of arbitrary meridian. Although...

Topics: DTIC Archive, Abel, J F, CALIFORNIA UNIV BERKELEY DEPT OF CIVIL ENGINEERING, *STRESS STRAIN...

The optimal design of a pitched tapered laminated woood beam is considered. An engineering formulation is given in which the volume of the beam is minimized. The problem is then reformulated and solved as a generalized geometric (signomial) program. Sample designs are presented.

Topics: DTIC Archive, Avriel, M., Barrett, J. D., STANFORD UNIV CA SYSTEMS OPTIMIZATION LAB, *LAMINATES,...

BEAM (Beam Element Analysis with Mechanisms) is a finite element program for the analysis of the collapse of vehicle structures. BEAM can quickly estimate the collapse load and plastic hinge locations in three-dimensional thin-walled frames that would collapse in bending. Such information can be combined with separate rigid-plastic modelling to enable the large-deflection design of vehicle frameworks so that their collapse in roll-over accidents, for instance, can be prevented. One advantage of...

Topics: DTIC Archive, Cimpoeru, S J, MATERIALS RESEARCH LABS ASCOT VALE (AUSTRALIA), *STRUCTURAL MECHANICS,...

Theoretical expressions for bending moment versus depth of elastic- plastic interface for both rectangular, tubular, and solid circular beams are developed. Theoretical expressions for strain as a function of geometry and depth of elastic-plastic interface for each type of cross section are derived. The possibility of a strain singularity occurring as the elastic-plastic interface approaches the neutral axis is pointed out. The assumption that 'planes remain plane' is examined. Experimental...

Topics: DTIC Archive, Milligan, R V, ARMY ARMAMENT RESEARCH AND DEVELOPMENT CENTER WATERVLIET NY LARGE...

The effect of initial curvature on the trust-moment characteristics of reinforced concrete circular conduit sections was investigated. This study was undertaken since conduit sections built by the Corps of Engineers are often so sharply curved relative to their thicknesses that initial curvature effects might be significant. The effect of initial curvature was investigated through curved beam, Airy stress function, and nonlinear finite element analyses. In addition, three model conduits...

Topics: DTIC Archive, Chiarito,Vincent P, ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MS...

The objective of this study was to develop, review, and analyze selected case histories involving applications of precast concrete in the repair or replacement of civil works structures. Information was obtained through literature searches; discussions with designers, precasters, and contractors; visits to project sites; and discussions with project personnel. Each case history includes a description of the project, the cause and extent of the deficiency that necessitated repair or replacement,...

Topics: DTIC Archive, McDonald, James E., ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MS,...

The use of pressure stabilized structural elements in tentage support structures has been under investigation for several years. The work reported here culminates the exploratory development phase of this investigation with a description of the fabrication and simulated snow load testing of several prototype concepts. In addition, some preliminary study of the fabrication of pressure stabilized structural elements is reported, including weaving and air retention techniques. The test results...

Topics: DTIC Archive, Steeves, Earl C, ARMY NATICK RESEARCH AND DEVELOPMENT CENTER MA, *PORTABLE SHELTERS,...

Contents: Impact on Complex Mechanical Structures; Energy Absorption and Phase Effects in Shock Excited Coupled Systems; High Performance Vibration Isolation System for the DD963 Gears; The Design and Measurement of a High Impedance Foundation to 20 kHz and Use of the Data in Correcting Noise Measurements; Response of Thick Structures Damped by Viscoelastic Material with Application to Layered Beams and Plates; Controlling the Dynamic Response of Jet Engine Components; An Investigation of the...

Topics: DTIC Archive, NAVAL RESEARCH LAB WASHINGTON DC SHOCK AND VIBRATION INFORMATION CENTER, *DAMPING,...

The 1991 Active Materials and Adaptive Structures Conference was held to address the explosion in both theory and application of recent and ongoing developments in smart, intelligent, or adaptive structures. The many areas of intelligent systems and smart structures incorporating active materials are now emerging to include major areas of research and development. These include fiber-optic based devices; ferroelectric, shape memory, and electro-rheological- based sensors and actuators; hybrid...

Topics: DTIC Archive, Knowles, Gareth J, INSTITUTE OF PHYSICS LONDON (UNITED KINGDOM), *FIBER OPTICS,...

Session topics in this volume include: Vibration suppression; Free layer damping; Laminates; Launching; Model verification; Metals; Sandwich construction; Impact damping; Space applications. Keywords: Vibration detectors; Structural control; Structural components; Damping materials; Structural beams; Viscoelasticity; Space systems; Passive vibration control; Spacecraft components; Flexible structures; Mathematical models; Viscous damping; Aluminum indium alloys; Composite materials;...

Topics: DTIC Archive, WRIGHT RESEARCH AND DEVELOPMENT CENTER WRIGHT-PATTERSON AFB OH, *COMPOSITE MATERIALS,...

Investigated the applicability of the electrical resistance change method through experiments of CFRP laminates [16-18]. Instead of using two or four electrodes, this research adopted multiple electrodes mounted on the surface of the target structure to identify delamination location and dimension. Orthotropic electric conductivity was also measured experimentally for three types of fiber volume fractions, and the paper revealed that electric conductivity in thickness direction of CFRP was...

Topics: DTIC Archive, Todoroki, Akira, TOKYO INST OF TECH (JAPAN) DEPT OF MECHANICAL ENGINEERING,...

Contents: Computer Programs--Multiple Energy Domain Systems, Transfer Function Analysis, Dynamics of Spacecraft Structures, Torsional Systems, Crash Simulation, Highway Vehicle Simulation, Cable Systems, Offshore Structures Analysis, Frames, Nonlinear Transient Response of Solids, Time Dependent Materials, Prediction of Highway Noise, Liquid Propellant Dynamics Analysis, Optimum Design of Dynamic Mechanical Systems, Mechanical and Thermal Shock Analysis, Random Vibration of Structures, Beams,...

Topics: DTIC Archive, Pilkey, Walter, Pilkey, Barbara, VIRGINIA UNIV CHARLOTTESVILLE, *COMPUTER PROGRAMS,...

Experimental studies have been conducted on a large number of orthotropic composite plates of 0-90 degrees fiber orientation subjected to kinetic energy impactors and blast type loadings. The fiberglass-epoxy composites were tested at loadings below that required to cause penetration or complete failure. A systematic study of the resultant failure patterns is reported on and a proposed model for explaining the observed plate failure presented. Some quantitative measures of plate performance...

Topics: DTIC Archive, Sierakowski, R. L., Ross, C. A., Malvern, L. E., Cristescu, N., FLORIDA UNIV...

Design information is given to provide ship structural designers with convenient tabulations of the properties of built-up T-beams for the following high-strength materials: HY-80, HY-100, HY-130, and Ti 6Al-4V extra low interstitial. The T-beams are arranged in order of increasing sectional area for each material. Criteria for proportioning the T-beams are included in this report. The unit system used in the tables is English. No attempt has been made to convert to metric units at this time...

Topics: DTIC Archive, Zemanek,Stephen F, DAVID W TAYLOR NAVAL SHIP RESEARCH AND DEVELOPMENT CENTER BETHESDA...

Theoretical expressions for bending moment versus depth of elastic- plastic interface for both rectangular, tubular, and solid circular beams are developed. Theoretical expressions for strain as a function of geometry and depth of elastic-plastic interface for each type of cross section are derived. The possibility of a strain singularity occurring as the elastic-plastic interface approaches the neutral axis is pointed out. The assumption that 'planes remain plane' is examined. Experimental...

Topics: DTIC Archive, Milligan, R V, ARMY ARMAMENT RESEARCH AND DEVELOPMENT CENTER WATERVLIET NY LARGE...

A total Lagrangian finite element scheme for arbitrarily large displacements and rotations is applied to a wide range of shell geometries. The scheme decomposes the deformation into stretches and rigid-body rotations, examining the deformed state with respect to an orthogonal, rigidly translated and rotated triad located at the point of interest on the deformed structure. The Jaumann stresses and strains, which are resolved along the axes of this triad, are employed in the algorithm. Local and...

Topics: DTIC Archive, Greer, James M., Jr, AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH, *STRESS STRAIN...

Elastic circular sandwich beams are designed for minimum compliance and given total weight. To treat the problem in a more realistic manner, the beams are regarded as extensible. Examples are given for the optimal design of circular rings and semicircular arches with different end conditions. The calculated optimal compliance is compared with the corresponding compliance of a uniform beam with identical weight. Finally, the optimal design with stress bounds is also investigated for the ring...

Topics: DTIC Archive, Huang, N C, CALIFORNIA UNIV SAN DIEGO LA JOLLA DEPT OF THE AEROSPACE AND MECHANICAL...

The subject of this paper is the buckling behavior of thin bar stiffeners attached to plates which are subjected to normal pressure loadings. The stiffeners are mathematically modeled by a nonlinear beam theory recently derived. An analytical solution is obtained to the beam buckling equations. The curvature of the centerline along the beam's base at the buckling load is expressed in terms of the beam's thickness, height, and rotational stiffness. Analytical results are compared with an...

Topics: DTIC Archive, Danielson, Donald, NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *STIFFENING, *BUCKLING,...

Our objective addresses the mechanics models needed and the suppression techniques offered by smart materials as applied to optical systems mounted on satellites. The objectives of this research effort are to model the dynamics and control of flexible optical systems for both vibration suppression and shape control using smart materials as the actuation component and sensing component. The specific objective was to model a generic system, select suitable actuation, sensing and control elements,...

Topics: DTIC Archive, Inman, Daniel J, VIRGINIA POLYTECHNIC INST AND STATE UNIV BLACKSBURG CENTER FOR...

The titles include: On the Dirichlet Neumann Boundary Control Problem Associated with Maxwell's Equations in a Cylindrical Region, A Floquet decomposition for Volterra Equations with Periodic Kernel and a transform Approach to Linear Recursion Equations, and Mathematical Models for the Elastic Beam and their Control Theoretic Implications, and Mathematical Models for the Elastic Beam with Frequency Proportional Damping.

Topics: DTIC Archive, Russell,David L, WISCONSIN UNIV-MADISON DEPT OF MATHEMATICS, *VIBRATION, *DAMPING,...

The displacement based finite element model of a general third-order beam theory is developed to study the quasi-static behavior of viscoelastic rectangular orthotropic beams. The mechanical properties are considered to be linear viscoelastic in nature with a scope to undergo von K rm n nonlinear geometric deformations. A differential constitutive law is developed for an orthotropic linear viscoelastic beam under the assumptions of plane-stress. The fully discretized finite element equations...

Topics: DTIC Archive, TEXAS A AND M UNIV COLLEGE STATION DEPT OF MECHANICAL ENGINEERING,...

This project seeks to study the estimation of elastic, damping, and material parameters inflexible structure. Of particular interest are problems in the design and estimation of parameters in structures made up of systems of coupled beams and plates, the estimation of parameters in models that may not have unique solutions, and the estimation and design of various plate and shell models incorporating, for example, large deformation, variable thickness, existing curvatures, contact and possible...

Topics: DTIC Archive, White, Luther, OKLAHOMA UNIV NORMAN DEPT OF MATHEMATICS, *ELASTIC PROPERTIES,...

This study investigates the effect of externally bonded carbon fiber reinforced plastic (CFRP) laminates on the ductility of reinforced concrete beams. Reinforced concrete structures deteriorate over time due to environmental aging, fatigue, excessive loading, chemical attack, and other factors. Strengthening and rehabilitating these concrete structures by externally bonding carbon laminates is one of many economical engineering solutions. Eight rectangular beams with varying internal steel...

Topics: DTIC Archive, Simmons, Duane K, NAVAL ACADEMY ANNAPOLIS MD, *FIBER REINFORCED COMPOSITES, *CARBON...

The literature on bending of beams made of bimodulus materials (which have one value of the elastic modulus in tension and another in compression) is limited. All of the works known to the present investigators are restricted to beams with natural boundary conditions and subjected to specific distributions of normal pressure only. In the present work, the transfer-matrix approach is used to determine the small-deflection static behavior of bimodulus beams, including transverse shear...

Topics: DTIC Archive, Bert,Charles W, OKLAHOMA UNIV NORMAN SCHOOL OF AEROSPACE MECHANICAL AND NUCLEAR...

Methods that can be used to increase (upgrade) the blast resistance of existing two-way reinforced concrete slab systems to a value near 50-psi overpressure from a 1-mt weapon were evaluated, Two nine-bay prototype structures, a flat plate and a two-way slab with beams, were designed in accordance with the 1977 ACI Code. Each structure had a basement area 60 feet square. A 1/4-scale model of each prototype was constructed, upgraded with 4- by 4-inch timber posts, and statically tested in the...

Topics: DTIC Archive, Woodson, Stanley C., ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MS...

This report presents the results of calculating the deflection and stresses in a thermally loaded beam. Three different methods were used for the calculation: classical beam theory, ANSYS (Version 4.4) and VAASEL (Version 1.1). Comparisons between each of the methods are presented.

Topics: DTIC Archive, Anselmo, Estelle R, WRIGHT LAB WRIGHT-PATTERSON AFB OH, *THERMAL SHOCK,...