Download or read book Experimental Simulations of Explosive Loading on Structural Components written by Tonatiuh Rodríguez-Nikl and published by . This book was released on 2006 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: The dissertation responds to the need for efficient techniques for testing and validating protective technologies to resist explosive loading on civil structures; the newly-developed Explosive Loading Laboratory allows investigators to simulate explosive blast loading at a lower cost and with better data than when using real explosives. Analytical tools are developed for the new laboratory and comparisons between real and simulated explosive tests confirm that the two are equivalent. These developments provide future investigators with confidence in the simulated blast methodology and tools to predict results and analyze the data, thus setting the stage for decades of fruitful research in a nascent field of simulated explosive testing. The simulated blast load is applied via specially designed apparatuses called blast generators, each of which is made of a high speed actuator that accelerates an impacting module towards the specimen. An elastomeric pad, called the programmer, on the front of the impacting module provides a blast-like pressure pulse to the specimen. The entire setup is housed in a post-tensioned, self-reacting, reinforced concrete reaction structure. An inaugural series of tests on column specimens provides data on structural behavior and on the functioning of the laboratory. New methods of data analysis are developed: the equivalent uniform load method reduces the load recorded on multiple channels to a single, rationally-derived value, and the equivalent charge method translates the experimental results to an equivalent real scenario. Because there is no fireball to obscure the specimen during the blast, the verbal descriptions and video stills herein are the first-ever visual record of structural behavior under blast loading. The laboratory results are corroborated with field test data via qualitative comparisons and demand-damage plots to demonstrate the validity of simulated blast testing. A methodology is developed for quickly and easily determining the necessary velocity of the impacting module to deliver a desired impulse to the specimen. Load-deformation programmer data are collected and a phenomenological model of programmer behavior is derived for use in detailed pre-test analyses, including finite element implementations. Both tools are derived theoretically, calibrated to experimental data, and verified against independent experimental data.
Download or read book Experimental and Numerical Simulations of Explosive Loading on Structural Components written by Peter N. Huson and published by . This book was released on 2012 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: The extreme loading conditions produced from the detonation of an explosive are severely detrimental to structures and structural components. These effects are amplified when a blast occurs in an enclosed or confined geometry, where reduced ventilation and oblique angles result in extended pulse durations and added reflections of generated pressures. The objective of this dissertation is to develop experimental methodologies and numerical assessment tools to document and simulate failure sequences in composite sandwich connections under simulated internal blast loads. The experimental research was conducted using the UCSD Blast Simulator, a one-of-a-kind system able to simulate explosive events without the use of explosive materials and therefore without the associated fireballs. This is accomplished with an array of high velocity hydraulic actuators driven by a combined high pressure nitrogen/hydraulic energy source. In explosive field testing, video and data from instrumentation is often lost to the destructive nature of the blast environment. The simulator allows for the generation of high fidelity data that documents the response and failure progression in structural members, which in turn lends researchers the ability to develop and test damage mitigation strategies as well as design guidelines for critical infrastructure subject to impulsive loads. First, the development of loading protocols were presented, in which pressures of prolonged durations distributed in multiple directions were achieved through the impact of high strength water filled bladders. These methods were then implemented in the testing of 90 degree composite sandwich joint specimens, which were reacted via adjustable steel gripping fixtures mounted in configurations suitable for impact with the high powered Blast Generators. In an effort to create a numerical model capable of simulating the failure modes observed in the Blast Simulator experiments, a series of individual component tests were conducted to assist in the calibration of finite element material models. The characterization of the CFRP facesheet/balsa wood core sandwich material's failure properties in bending, shear and delamination were documented experimentally and validated numerically using LS-DYNA under both quasi-static and dynamic load rates. Finally, the updated material models were implemented into the simulation of the Composite Joint Tests, which highlight the key mechanisms involved in connection failure and ultimately joint breach. The studies found that failure of the connection structure were functions of the bond strength between the panel facesheets and overlaminate used to adhere the sandwich panels together, strongly coupled with the shear capacity of the individual panel cores. Recommendations for improved joint design were made and suggestions for extrapolation of the developed technologies to larger scale testing were offered.
Download or read book Design Against Blast written by S. Syngellakis and published by WIT Press. This book was released on 2013 with total page 225 pages. Available in PDF, EPUB and Kindle. Book excerpt: Terrorist attacks and other destructive incidents caused by explosives have, in recent years, prompted considerable research and development into the protection of structures against blast loads. For this objective to be achieved, experiments have been performed and theoretical studies carried out to improve our assessments of the intensity as well as the space-time distribution of the resulting blast pressure on the one hand and the consequences of an explosion to the exposed environment on the other.This book aims to enhance awareness on and understanding of these topical issues through a collection of relevant, Transactions of the Wessex Institute of Technology articles written by experts in the field. The book starts with an overview of key physics-based algorithms for blast and fragment environment characterisation, structural response analyses and structural assessments with reference to a terrorist attack in an urban environment and the management of its inherent uncertainties.A subsequent group of articles is concerned with the accurate definition of blast pressure, which is an essential prerequisite to the reliable assessment of the consequences of an explosion. Other papers are concerned with alternative methods for the determination of blast pressure, based on experimental measurements or neural networks. A final group of articles reports investigations on predicting the response of specific structural entities and their contents.The book concludes with studies on the effectiveness of steel-reinforced polymer in improving the performance of reinforced concrete columns and the failure mechanisms of seamless steel pipes used in nuclear industry.
Download or read book Explosive Loading of Engineering Structures written by P.S. Bulson and published by CRC Press. This book was released on 1997-07-24 with total page 269 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reviews the development of research into the explosive loading of structures, mainly since the beginning of the twentieth century. Major contributions in the fields of measurement, analysis and prediction are discussed. Dynamic loading from conventional high explosives is examined, as well as the effects of liquid propellant, dust, gas, v
Download or read book Explosion Systems with Inert High Modulus Components written by Igor A. Balagansky and published by John Wiley & Sons. This book was released on 2019-06-12 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes in one volume the data received during experiments on detonation in high explosive charges This book brings together, in one volume, information normally covered in a series of journal articles on high explosive detonation tests, so that developers can create new explosive technologies. It focuses on the charges that contain inert elements made of materials in which a sound velocity is significantly higher than a detonation velocity. It also summarizes the results of experimental, numerical, and theoretical investigations of explosion systems, which contain high modulus ceramic components. The phenomena occurring in such systems are described in detail: desensitization of high explosives, nonstationary detonation processes, energy focusing, and Mach stems formation. Formation of hypersonic flows of ceramic particles arising due to explosive collapse of ceramic tubes is another example of the issues discussed. Explosion Systems with Inert High Modulus Components: Increasing the Efficiency of Blast Technologies and Their Applications also looks at the design of explosion protective structures based on high modulus ceramic materials. The structural transformations, caused in metallic materials by the energy focusing, or by the impact of hypersonic ceramic jets are also discussed. These transformations include, but not limited to adiabatic shear banding, phase transformations, mechanical twinning, melting, boiling, and even evaporation of the impacted substrates. Specifically discusses in one volume the explosions involved with inert high modules components normally scattered over numerous journal articles Covers methods to increase energy output of a weak explosive by encasing it in a higher explosive Discusses the specifics of explosive systems containing high modulus inert elements Details the process of detonation and related phenomena, as well as the design of novel highly performant explosive systems Describes the transformation in materials impacted due to explosion in such systems Explosion Systems with Inert High Modulus Components will be of great interest to specialists working in fields of energy of the explosion and explosion safety as well as university staff, students, and postgraduate students studying explosion phenomena, explosive technologies, explosion safety, and materials science.
Download or read book Blast and Ballistic Loading of Structures written by John Hetherington and published by CRC Press. This book was released on 2014-04-21 with total page 333 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book brings together, in a concise format, the key elements of the loads produced from explosive sources, and how they interact with structures. Explosive sources include gas, high explosives, dust and nuclear materials.It presents quantitative information and design methods in a useable form without recourse to extensive mathematical ana
Download or read book Explosions in Air written by Wilfred Edmund Baker and published by . This book was released on 1973 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental and Applied Mechanics Volume 6 written by Tom Proulx and published by Springer Science & Business Media. This book was released on 2011-05-27 with total page 649 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experimental and Applied Mechanics represents one of eight volumes of technical papers presented at the Society for Experimental Mechanics Annual Conference on Experimental and Applied Mechanics, held at Uncasville, Connecticut, June 13-16, 2011. The full set of proceedings also includes volumes on Dynamic Behavior of Materials, Mechanics of Biological Systems and Materials, Challenges in Mechanics of Time-Dependent Materials and Processes in Conventional and Multifunctional Materials, MEMS and Nanotechnology; Optical Measurements, Modeling and, Metrology; Experimental and Applied Mechanics, Thermomechanics and Infra-Red Imaging, and Engineering Applications of Residual Stress.
Download or read book EASEC16 written by Chien Ming Wang and published by Springer Nature. This book was released on 2020-12-22 with total page 2093 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents articles from The 16th East Asian-Pacific Conference on Structural Engineering and Construction, 2019, held in Brisbane, Australia. It provides a forum for professional engineers, academics, researchers and contractors to present recent research and developments in structural engineering and construction.
Download or read book Explosion Systems with Inert High Modulus Components written by Igor A. Balagansky and published by John Wiley & Sons. This book was released on 2019-07-19 with total page 255 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes in one volume the data received during experiments on detonation in high explosive charges This book brings together, in one volume, information normally covered in a series of journal articles on high explosive detonation tests, so that developers can create new explosive technologies. It focuses on the charges that contain inert elements made of materials in which a sound velocity is significantly higher than a detonation velocity. It also summarizes the results of experimental, numerical, and theoretical investigations of explosion systems, which contain high modulus ceramic components. The phenomena occurring in such systems are described in detail: desensitization of high explosives, nonstationary detonation processes, energy focusing, and Mach stems formation. Formation of hypersonic flows of ceramic particles arising due to explosive collapse of ceramic tubes is another example of the issues discussed. Explosion Systems with Inert High Modulus Components: Increasing the Efficiency of Blast Technologies and Their Applications also looks at the design of explosion protective structures based on high modulus ceramic materials. The structural transformations, caused in metallic materials by the energy focusing, or by the impact of hypersonic ceramic jets are also discussed. These transformations include, but not limited to adiabatic shear banding, phase transformations, mechanical twinning, melting, boiling, and even evaporation of the impacted substrates. Specifically discusses in one volume the explosions involved with inert high modules components normally scattered over numerous journal articles Covers methods to increase energy output of a weak explosive by encasing it in a higher explosive Discusses the specifics of explosive systems containing high modulus inert elements Details the process of detonation and related phenomena, as well as the design of novel highly performant explosive systems Describes the transformation in materials impacted due to explosion in such systems Explosion Systems with Inert High Modulus Components will be of great interest to specialists working in fields of energy of the explosion and explosion safety as well as university staff, students, and postgraduate students studying explosion phenomena, explosive technologies, explosion safety, and materials science.
Download or read book Computational and Experimental Simulations in Engineering written by Shaofan Li and published by Springer Nature. This book was released on with total page 1358 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Mechanics and Effects of Intensive Loading written by Lin Wang and published by Trans Tech Publications Ltd. This book was released on 2015-08-06 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: Collection of selected, peer reviewed papers from the 2014 SEM Fall Conference and International Symposium on Intensive Loading and Its Effects, October 19-22, 2014, Beijing, China. The 46 papers are grouped as follows: Chapter 1: Plenary and Invited Talks; Chapter 2: Mechanical Properties of Materials; Chapter 3: Materials and Structures under Extreme Loading Conditions; Chapter 4: Computational Experiments and Simulation; Chapter 5: Advanced Diagnostic and Measurement Methods
Download or read book Structural Design for Dynamic Loads written by Charles Head Norris and published by . This book was released on 1959 with total page 453 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Innovative Protective Jacket for Structures Subject to Blast Loads written by Nicholas J. Carlson and published by . This book was released on 2013 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the importance of protective engineering and multi-hazard mitigation design has grown in recent years, the development of an effective structural protection system that aids in the preservation of life safety during blast events is an important topic of research in structural engineering. This protection is especially vital for blast and explosion mitigation, where a vehicle-borne bomb or an improvised explosive device can readily cause an under-designed structure with insufficient redundancy to undergo progressive collapse due to the removal of its first-floor columns. An especially pressing research need is the consideration of structures that require blast protection, but--due to time or budget constraints, lack of available space, unusual construction techniques or other externalities--cannot be sufficiently strengthened by traditional structural hardening techniques such as those described in the FEMA counterterrorism design primers. As an alternative, the author proposes the development of an ablative, sacrificial protective jacket, based on prior research on the use of water as hazard mitigation to protect weapon storage facilities from accidental munitions detonation. The proposed system consists of a relatively thick layer of water sandwiched between two thin layers of polyethylene film or a similar polymer membrane, with the entire assembly wrapped around or affixed to the vulnerable structural elements. The water layer is theorized to reduce the incident and reflected pressure of the blast wave through two principal modes of attenuation: the reduction of the blast wave's energy through harnessing the high enthalpy of fusion and specific heat of water (the "thermodynamic mode") and the transformation of the blast pressure into kinetic energy (the "kinetic mode"). The theoretical mitigation pathways are discussed and analyzed, and the necessary assumptions required for the jacket to mobilize its protective capacity within the short timescale of a blast event are shown to be valid--namely, that the initial disruption of the water layer by the blast wave forms an ultra-fine mist of 20 μm to 30 μm diameter droplets that can evaporate in approximately 1 ms. The investigation of the ablative ability of the proposed, 1.5 in to 6.0 in protective jackets takes the form of a series of two- and three-dimensional finite element simulations which measure the protective capacity of various water jacket volumes protecting various structures from both impact and blast. For the blast loads (scaled standoffs from 5 ft/lb1/3 and 1.25 ft/lb1/3) and structural configuration chosen, the optimum energy reduction occurs when the jacket is approximately 4.5 in thick. For cases where a thinner jacket is desired, the author used the relative energy dissipation data to derive an empirical relationship between the thickness of a jacket, the blast load it is subjected to and its predicted energy dissipation capacity. This relationship can be used by design engineers to use the proposed design method, employing the integrals of P--0 pushover curves, in order to meet important performance criteria that ensure life safety during catastrophic events.
Download or read book Numerical Simulations for Classification of Blast Loaded Laminated Glass written by Alexander Stolz and published by . This book was released on 2014 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is important to protect critical buildings (shopping centres, government buildings and embassies), infrastructure and utilities, train and underground stations against being damaged, destroyed or disrupted by deliberate acts of terrorism, criminal activity and malicious behaviour. Normal regulations and building guidelines do not generally take into account these threats. The introduction of appropriate regulations or guidelines, where deemed necessary, should, enhance the resilience of buildings and infrastructure against explosion incidents. In order to protect the built infrastructure, methods are required to quantify the resistance of structural components against explosive loading and to assess the hazards resulting from the failure of an element. The applicable state-of-the-art techniques may include either experimental or numerical methods, or a combination of both.^Therefore, the thematic group (TG) on the resistance of structures to explosion effects was formed in order to bring the required expertise together, make it commonly available and to find and define harmonised methods and solutions which can be provided to the decision-makers responsible for critical infrastructure protection. The current report summarizes existing best practices for the numerical finite element modelling of blast loading, including the important topics of domain discretisation, implicit/explicit formulation, Lagrangian/Eulerian solvers, the mathematical description of the material behaviour etc. Furthermore recommendations for the modelling of laminated glass elements are formulated and knowledge gaps in this application area are pointed out. Hence the report builds the basis for an actual evaluation of the different numerical methods, their suitability to certain problems, and their capability to support/complement the experimental testing of glass components.^It thus provides helpful information to design architects and engineers, and more generally to critical infrastructure stakeholders, responsible for the structural integrity and security of the infrastructure in case of an explosion.
Download or read book Explosions in Complex Geometries written by and published by . This book was released on 2010 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: For the design and calculation of structures loaded by air blast waves, especially from inside the structure, assumptions on the applied load are needed. This paper presents several simulation methods for the air blast loading of structures and their ability to be used for complex geometries. Experimental-analytical pressure-time functions of spherical load conditions applied to the structure by disregarding the air are not applicable in such cases because they do not account for reflections, shadowing and channelling effects. Fluid calculations, which model also the solid explosive, are very expensive due to the extremely small elements for the explosive and the air nearby. This paper therefore presents a review of a well-known simulation method, which uses a balloon with compressed air instead of the explosive. A procedure is developed which makes it possible to determine the overpressure of such a balloon for a given size of the explosive more accurately than before. The pressure-time function and the impulse-distance function of calculations using this method show good correspondence with experimental-analytical data. The functioning of the method is verified against experimental results.
Download or read book Explosive Bonding written by V. D. Linse and published by . This book was released on 1967 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes basic mechanics of the process, practices of those in the field, metal combinations and configurations that have been bonded, and applications.
