Download or read book Concrete Stress Measurement Using Acoustic Wave Methods written by Ke Peng and published by . This book was released on 2016 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stress measurement in concrete structures is challenging due to the heterogeneous characteristics of concrete components. As a result, methods based on stress-relieving, including core drilling or slot cutting, are the only ones that able to measure in-situ stresses in concrete members. Other methods such as strain gauges, can only measure the change of stresses. The stress-relieving methods are based on the assumption that the concrete is linearly elastic and the stress distribution along the depth is uniform, and the modulus of elasticity of concrete can be accurately measured. In addition, the stress-relieving methods cause damage to concrete. This research explores the potential of linear and non-linear ultrasonic methods for measuring stresses in concrete structures to seek a nondestructive testing approach. Concrete specimens with 0.35, 0.5 and 0.65 water-to-cement (W/C) ratios were prepared and tested under various loading levels. The sensitivity of acoustic wave velocity, amplitude, first wave area, and the second and third harmonics to stress changes were evaluated. The loading was increased at an increment of approximately 2% of the ultimate compressive strength. In general, there is an obvious change at 40% of the ultimate compressive stress, and a sign of large damage at 60%. In the non-linear ultrasound test, the amplitudes of the fundamental, the second, and third harmonic waves all decrease with the increase of stress, and the third harmonic signal is the most sensitive to the change of stress; as for the linear ultrasound test, the first wave area and maximum amplitude of the S-wave are the most sensitive to stress, and the S-wave is generally more sensitive than the P-wave. Among the three W/C ratios (0.35, 0.5, and 0.65), the sensitivity of the amplitude decreases with the increase of W/C ratio, while the sensitivity of the harmonic amplitude ratios increases. The research demonstrated that notable correlations exist between acoustic parameters and stresses. To improve the accuracy and efficiency of the acoustic wave testing, six different materials were evaluated as couplants according to their efficiency of transmission and convenience of use. Among the six materials, water was found the most efficient, but cannot use in long-term testing; the efficiency drops in the order of CIP lube, lube, honey, candle wax, Duco glue and Crazy Aaron's liquid glass putty. Although the liquid glass putty is the most convenient to use, candle wax is considered the best choice as a couplant.

Download or read book Acoustic Wave Measurements for Dynamic and Static Properties and Higher Order Elastic Constants of Concrete written by Weihao Dai and published by . This book was released on 2016 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: Concrete is one of the most widely used construction materials in the world today. As a composite of cement, water and aggregates, concrete has unique engineering properties including nonlinear elasticity. To measure the nonlinearity of concrete, higher order elastic constants are used together with other physical properties including the modulus of elasticity, Poisson’s ratio, and Lamé constants. This research estimates the basic properties of concrete by using the acoustic wave method and the results are compared to those obtained by traditional methods. Concrete specimens with water/cement ratios of 0.35, 0.5, and 0.65 were made, 76.2mm (3in) x 101.6mm (4in) x 406.4mm (16in) in dimension. Acoustic wave parameters, including the travel velocity and amplitude, were recorded at various stress levels under applied compressive loading, in the range of 0-30% of the ultimate strength. Both linear and non-linear acoustic wave techniques were used, including the pulse velocities of longitudinal and shear waves, and the maximum amplitudes at the fundamental, second harmonic and third harmonic frequencies. The physical properties of concrete measured include the static and dynamic moduli of elasticity, Poison’s ratio, Lamé́ constants, and the second and third order elastic constants.

Download or read book Impact echo written by Mary Sansalone and published by . This book was released on 1997 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Applications and Techniques for Experimental Stress Analysis written by Karuppasamy, Karthik Selva Kumar and published by IGI Global. This book was released on 2019-12-27 with total page 269 pages. Available in PDF, EPUB and Kindle. Book excerpt: The design of mechanical components for various engineering applications requires the understanding of stress distribution in the materials. The need of determining the nature of stress distribution on the components can be achieved with experimental techniques. Applications and Techniques for Experimental Stress Analysis is a timely research publication that examines how experimental stress analysis supports the development and validation of analytical and numerical models, the progress of phenomenological concepts, the measurement and control of system parameters under working conditions, and identification of sources of failure or malfunction. Highlighting a range of topics such as deformation, strain measurement, and element analysis, this book is essential for mechanical engineers, civil engineers, designers, aerospace engineers, researchers, industry professionals, academicians, and students.

Download or read book Strength and Related Properties of Concrete written by Sándor Popovics and published by John Wiley & Sons. This book was released on 1998-03-23 with total page 558 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work discusses the variations that occur in the strength of concrete and presents numerical methods useful in interpreting these variations. Individual chapters include the relationship between composition and strength of concrete.

Download or read book Review of Progress in Quantitative Nondestructive Evaluation written by Donald O. Thompson and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 2362 pages. Available in PDF, EPUB and Kindle. Book excerpt: This authoritative and up-to-date series provides a comprehensive review of the latest research results in quantitative nondestructive evaluation (NDE). Leading investigators working in government agencies, major industries, and universities present a broad spectrum of work extending from basic research to early engineering applications.

Download or read book Advanced Techniques for Testing of Cement Based Materials written by Marijana Serdar and published by Springer Nature. This book was released on 2020-02-18 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book examines advanced, non-standardized techniques that have been developed for determining different properties of cement paste, mortar and concrete, and provides state-of-the-art information on methods for monitoring hydration-induced changes in cement-based materials (CBMs). These methods are often nondestructive and allow quasi-continuous monitoring covering the time span from placement of the material to formation of a fully hardened cement composite. The book also presents various applications of acoustic emission for characterizing fresh concrete, recent developments in ultrasonic methods for characterizing CBMs since placement, application of ambient response methods for measuring elastic modulus, methods for determining deformational characteristics of CBMs since setting and methods for in situ measurements of stresses in concrete elements during hardening.

Download or read book Water Conservancy and Civil Construction Volume 1 written by Saheed Adeyinka Oke and published by CRC Press. This book was released on 2023-08-17 with total page 973 pages. Available in PDF, EPUB and Kindle. Book excerpt: Water Conservancy and Civil Construction gathers the most cutting-edge research on: Water Conservancy Projects Civil Engineering Construction Technology and Process The book is aimed at academics and engineers in water and civil engineering.

Download or read book NBS Special Publication written by and published by . This book was released on 1968 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nondestructive Evaluation Techniques Using Impact generated Stress Waves in Concrete written by Won-Joon Song and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this dissertation, non-destructive evaluation techniques using impact-generated stress waves for the measurement of longitudinal and the surface wave velocities and the surface wave transmission coefficient across a surface-breaking crack or a notch in concrete are developed.

Download or read book Nonlinear Ultrasonic and Vibro Acoustical Techniques for Nondestructive Evaluation written by Tribikram Kundu and published by Springer. This book was released on 2018-10-19 with total page 761 pages. Available in PDF, EPUB and Kindle. Book excerpt: This multi-contributed volume provides a practical, applications-focused introduction to nonlinear acoustical techniques for nondestructive evaluation. Compared to linear techniques, nonlinear acoustical/ultrasonic techniques are much more sensitive to micro-cracks and other types of small distributed damages. Most materials and structures exhibit nonlinear behavior due to the formation of dislocation and micro-cracks from fatigue or other types of repetitive loadings well before detectable macro-cracks are formed. Nondestructive evaluation (NDE) tools that have been developed based on nonlinear acoustical techniques are capable of providing early warnings about the possibility of structural failure before detectable macro-cracks are formed. This book presents the full range of nonlinear acoustical techniques used today for NDE. The expert chapters cover both theoretical and experimental aspects, but always with an eye towards applications. Unlike other titles currently available, which treat nonlinearity as a physics problem and focus on different analytical derivations, the present volume emphasizes NDE applications over detailed analytical derivations. The introductory chapter presents the fundamentals in a manner accessible to anyone with an undergraduate degree in Engineering or Physics and equips the reader with all of the necessary background to understand the remaining chapters. This self-contained volume will be a valuable reference to graduate students through practising researchers in Engineering, Materials Science, and Physics. Represents the first book on nonlinear acoustical techniques for NDE applications Emphasizes applications of nonlinear acoustical techniques Presents the fundamental physics and mathematics behind nonlinear acoustical phenomenon in a simple, easily understood manner Covers a variety of popular NDE techniques based on nonlinear acoustics in a single volume

Download or read book Modeling and Measurement Methods for Acoustic Waves and for Acoustic Microdevices written by Marco G. Beghi and published by BoD – Books on Demand. This book was released on 2013-08-28 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt: Acoustics is a mature field which enjoys a never ending youth. New developments are induced by either the search for a better understanding, or by technological innovations. Micro-fabrication techniques introduced a whole new class of microdevices, which exploit acoustic waves for various tasks, and in particular for information processing and for sensing purposes. Performance improvements are achievable by better modelling tools, able to deal with more complex configurations, and by more refined techniques of fabrication and of integration in technological systems, like wireless communications. Several chapters of this book deal with modelling and fabrication techniques for microdevices, including unconventional phenomena and configurations. But this is far from exhausting the research lines in acoustics. Theoretical analyses and modelling techniques are presented, for phenomena ranging from the detection of cracks to the acoustics of the oceans. Measurement methods are also discussed, which probe by acoustic waves the properties of widely different systems.

Download or read book Applied mechanics reviews written by and published by . This book was released on 1948 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Journal of Research of the National Bureau of Standards written by United States. National Bureau of Standards and published by . This book was released on 1988 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Smart Sensors for Structural Health Monitoring written by Simon Laflamme and published by MDPI. This book was released on 2019-11-13 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: Smart sensors are technologies designed to facilitate the monitoring operations. For instance, power consumption can be minimized through on-board processing and smart interrogation algorithms, and state detection enhanced through collaboration between sensor nodes. Applied to structural health monitoring, smart sensors are key enablers of sparse and dense sensor networks capable of monitoring full-scale structures and components. They are also critical in empowering operators with decision making capabilities. The objective of this Special Issue is to generate discussions on the latest advances in research on smart sensing technologies for structural health monitoring applications, with a focus on decision-enabling systems. This Special Issue covers a wide range of related topics such as innovative sensors and sensing technologies for crack, displacement, and sudden event monitoring, sensor optimization, and novel sensor data processing algorithms for damage and defect detection, operational modal analysis, and system identification of a wide variety of structures (bridges, transmission line towers, high-speed trains, masonry light houses, etc.).

Download or read book ACI Manual of Concrete Inspection written by and published by American Concrete Institute. This book was released on 2008 with total page 203 pages. Available in PDF, EPUB and Kindle. Book excerpt: This manual is intended to guide, assist, and instruct concrete inspectors and others engaged in concrete construction and testing, including field engineers, construction superintendents, supervisors, laboratory and field technicians, and workers. Designers may also find the manual to be a valuable reference by using the information to better adapt their designs to the realities of field construction. Because of the diverse possible uses of the manual and the varied backgrounds of the readers, it includes the reasoning behind the technical instructions. The field of concrete construction has expanded dramatically over the years to reflect the many advances that have taken place in the concrete industry. Although many of the fundamentals presented in previous editions of this manual remain relevant and technically correct, this eleventh edition incorporates new material to address these advances in technology

Download or read book Fifth European Workshop on Structural Health Monitoring 2010 written by Fabio Casciati and published by DEStech Publications, Inc. This book was released on 2010 with total page 1425 pages. Available in PDF, EPUB and Kindle. Book excerpt: