Download or read book Brittle Matrix Composites 9 written by A M Brandt and published by Elsevier. This book was released on 2009-11-30 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: The subjects of the symposia are on composite materials with matrices behaving as brittle in normal or special conditions. Brittle matrix composites are applied in various domains (civil engineering, mechanical equipment and machinery, vehicles, etc.) and in the last decades their importance is increasing together with their variety. Papers include: aggregate-binder composites (concretes, fibre concretes, rocks); sintered materials (ceramics); high strength composites with brittle matrices. In principle, the general problems of structures made of composite materials are not included in the papers. Various approaches to the material engineering problems are presented in the papers.

Download or read book High Performance Brittle Matrices and Brittle Matrix Composites written by Anthony G. Evans and published by . This book was released on 1989 with total page 285 pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary intent of this research was the development of composites having an acceptable combination of toughness and oxidation resistance. The research was closely coordinated with the DARPA/ONR URI program as UCSB concerned with high temperature, high performance composites. The study comprised three tasks. The first task was to study phase equilibria, solidification pathways and toughness properties of intermetallics, such as oxidation resistance Ti-Al-Ta and Nb-Al-Si alloys, and ceramics. These studies were then combined with interface interaction studies between the matrix microstructure and ductilizing/toughening particulates and fibers. The second task was a basic study of interface structure and chemistry as it relates to the mechanical properties of the interface. The third task involved studies on aluminum and copper matrix composites. These studies were concerned with developing an understanding of creep resistance. Keywords: Phase diagrams, Solidification, Composites, Toughening residual stress. (JES).

Download or read book High Performance Brittle Matrices and Brittle Matrix Composites written by Anthony G. Evans and published by . This book was released on 1989 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary intent of this research was the development of composites having an acceptable combination of toughness and oxidation resistance. The research was closely coordinated with the DARPA/ONR URI program at UCSB concerned with high temperature, high performance composites. The study comprised three tasks. The first task was to study phase equilibria, solidification pathways and toughness properties of intermetallics, such as oxidation resistant Ti-Al-Ta and Nb-Al-Si alloys, and ceramics. These studies were then combined with interface interaction studies between the matrix microstructure and ductilizing/toughening particulates an fibers. The second task was a basic study of interface structure and chemistry as it relates to the mechanical properties of the interface. The third task involved studies on aluminum and copper matrix composites. These studies were concerned with developing an understanding of creep resistance. Keywords: Phase diagrams, Solidification, Composites, Toughening residual stress. (JES).

Download or read book Brittle Matrix Composites 8 written by A. M. Brandt and published by Woodhead Pub Limited. This book was released on 2006 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt: The subjects of the Symposia are on composite materials with matrices behaving as brittle in normal or special conditions. Brittle matrix composites are applied in various domains (civil engineering, mechanical equipment and machinery, vehicles, etc.) and in the last decades their importance is increasing together with their variety. papers include: aggregate-binder composites (concretes, fiber concretes, rocks); sintered materials (ceramics); high strength composites with brittle matrices. In principle, the general problems of structures made of composite materials are not included in the papers. Various approaches to the material engineering problems are presented in the papers. Among others: Design and optimization of the structure of materials; Theoretical considerations and computational methods; Models of materials and prediction of material properties; Test methods and new test results; Manufacturing processes; Applications of new materials and their behaviour in service; Durability assessments and environmental effects.

Download or read book Brittle Matrix Composites written by Johan Van Ackeren and published by Elsevier Inc. Chapters. This book was released on 2012-11-12 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper aims to get insight into the physical significance of the results obtained from curve fitting of a stochastic cracking model on experimental tensile stress-strain data of cementitious composites which are uniaxially reinforced with continuous fibre bundles of different kinds, such as glass, basalt, carbon, polyethylene and polyvinyl alcohol fibres. An experimental test program is performed on the different composites containing typically 20% in volume of fibres, as well on the fibre bundles themselves. A short introduction is given to the theory behind the stochastic cracking model, based on a Weibull distribution of the matrix cracking stress, which is used for modelling the experimental results. The obtained tensile stress–strain curves are analysed by means of curve fitting and an attempt is made to draw conclusions on the physical meaning of these results. The experimental results of tensile tests on specimens with an inorganic phosphate cement matrix containing the different fibre types, revealed a wide range of mechanical behaviour: carbon fibres result in a very stiff material, PE fibres in a very strong material, while the use of PVA fibres results in a very flexible and ductile composite. Curve fitting of the stochastic cracking model on the experimental data was successfully performed, leading to the identification of the Weibull model parameters. The reference cracking strength was found to be much higher than the mean matrix cracking strength. An interpretation, based on the phenomenon of crack suppression, is given for these high values compared to those found in literature for cement composites.

Download or read book Brittle Matrix Composites 7 written by A M Brandt and published by Woodhead Publishing. This book was released on 2003-10 with total page 582 pages. Available in PDF, EPUB and Kindle. Book excerpt: The International Symposium in Brittle Matrix Composites October 13-15, 2003 covers a wide spectrum of topics including cement based composites, ceramic composites and brittle polymer matrix composites. In the papers various topics and issues are considered such as: analytical and numerical studies related to the design of composites, prediction of behaviour and verification of strength and stability, testing methods, manufacturing processes and repair, environmental effects and durability assessment. The present volume of 55 papers proves that there are still many problems in the field of brittle matrix composites deserving theoretical and experimental investigations and that new solutions to these problems are needed for practical application in civil engineering, industrial structures, machinery and other domains.

Download or read book Brittle Matrix Composites 10 written by A M Brandt and published by Elsevier. This book was released on 2012-11-12 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt: The subjects of the symposia are on composite materials behaving as brittle, normal and special conditions of exploitation. Brittle matrix composites are applied in various domains and the series of symposia are closely related to their applications in civil engineering. In the last decades their importance is increasing along with their variety and the use of most advanced methods of testing. Papers include concretes, fibre concretes and ceramics, particularly their composition, microstructure and fracture processes. Various new and advanced engineering problems are presented in the papers.

Download or read book Brittle Matrix Composites 10 written by Andrzej Marek Brandt and published by . This book was released on 2012 with total page 409 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Brittle Matrix Composites written by Dominik Logoń and published by Elsevier Inc. Chapters. This book was released on 2012-11-12 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main motivation for this work was the attempt to limit the rapid destruction of brittle high performance concrete UPC and, in consequence, to obtain SRCC (safe rope effect cement composite). In the high performance fiber reinforced cement composites HPFRC deflection and flexural strength are increased. The rope effect in HPFRC results in a highly deflected damaged specimen with multicracking effect and with post-peak load at bending exceeding that corresponding to the first crack, which enables to obtain cement composite with the ability to absorb additional energy after the appearance of the macrocrack. The SRCC paste and mortar were presented in the previous paper. This paper shows different effects of the strengthening of cement concrete with dispersed synthetic structural polypropylene fibers 19 and 54mm long. The possibility to control multicracking and the crack propagation process using the rope effect for SRCC composites, which eliminates the catastrophic process of the destruction of composite, was presented and a new possibility of the strengthening effects assessment was suggested.

Download or read book Brittle Matrix Composites 5 written by A. M. Brandt and published by Woodhead Publishing Limited. This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fifth in a successful series of symposia this book contains the papers presented at BMC5 held in Warsaw, Poland in October 1997. The papers review the current status and developments on all aspects of brittle matrix composites associated with four main groups: high strength composites, brittle polymer composites, ceramics and cement based materials.

Download or read book Brittle Matrix Composites written by Tomasz Ponikiewski and published by Elsevier Inc. Chapters. This book was released on 2012-11-12 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: The paper presents results of tests on self-compacting mixtures with the addition of steel fibres (Steel Fibre Reinforced Self-Compacting Concrete). Four types of steel fibres at 3 levels of the volume ratio are considered. The results include studies on samples belonging to classes of slump flow SF, classes of viscosity T500, and rheological tests. The studies were based on application of two rheometers for rheological properties of concrete mixtures - BT2 Rheometer and Viskomat XL. Additionally, a study of compressive strength fcm,28 and flexural strength f was carried out on concrete SFRSCC. These studies have confirmed the possibility of using steel fibres in concrete SCC while maintaining the assumed technological parameters for concrete mixtures and, above all, their workability.

Download or read book Brittle Matrix Composites 3 written by Andrzej M Brandt and published by Springer. This book was released on 2013-03-26 with total page 606 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the third volume published in the series of proceedings of international symposia called 'Brittle Matrix Composites' organised every three years in Poland. The first Symposium, denoted as BMC1, was organised in Jablonna near Warsaw in 1985 under the auspices of the European Mechanics Committee (EUROMECH 204). The second (BMC2) took place in Cedzyna near Kielce in 1988; the present (BMC3) is being held in Warsaw in September 1991. The BMC Symposia are intended to cover mechanical problems related to three main groups of composite materials: high-strength composites, ceramics and cement-based materials. The common feature which is a link between these materials is their brittle behaviour. Brittleness has no clear definition, but it is considered as an important potential disadvantage of every material. Brittle fracture creates various situations which may be very dangerous for the safety and serviceability of structures manufactured from composite materials. Also the brittleness of non-structural elements may give rise to disadvan tageous behaviour, e.g. during transportation and montage. There are many structural and technological ways of reducing material brittleness. Their development and further improvement are of primordial importance for most applications of these composite materials. The problems considered in the series of BMC Symposia cover all aspects of brittle matrix composites: • design studies, theoretical considerations, computational methods; • prediction of behaviour, fracture mechanics and other approaches; • testing methods, test results, all types of experimental studies; • manufacturing processes, applications, observations and durability assess ments, environmental effects, etc.

Download or read book Brittle Matrix Composites written by and published by . This book was released on 1994 with total page 728 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Brittle Matrix Composites written by E Ghafari and published by Elsevier Inc. Chapters. This book was released on 2012-11-12 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultra-high performance concrete (UHPC) results from the mixture of several constituents giving rise to a highly complex material in hardened state. The higher number of constituents in relation to current concrete, together with a higher number of possible combinations and relative proportioning, makes the behavior of this type of concrete more difficult to predict. Until now, most of the proposed mixture design methods are based on a trial and error procedure, which is expensive and work intensive. Moreover, these methods are not efficient in predicting neither the consistency in fresh state nor the strength in hardened state, and do not consider the effect of curing on the latter. The main objective of the research study herein described is to build an analytical model, based on artificial neural networks (ANN), to predict the required performance of UHPC. Specifically, back-propagation neural networks (BPNN) are adopted to model the relation between the input and the output parameters of UHPC, for two different curing conditions, including heat treatment and water storage. In order to train the neural network, a total set of 53 different mixtures were designed. It is concluded that the developed model can be used as a reliable method to predict the performance of UHPC.

Download or read book Brittle Matrix Composites written by Andrzej M Brandt and published by Springer. This book was released on 1986-12-31 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt: The papers contained herein were presented at Euromech 204 'Structure and Crack Propagation in Brittle Matrix Composite Materials' held at Jablonna, Poland, from 12 to 15 November 1985. The Colloquium was organised and sponsored by The Institute of Fundamental Technological Research, Polish Academy of Sciences, under the auspices of the European Mechanics Committee (Euromech). The Euromech Committee is affiliated to the International Union of Theoretical and Applied Mechanics (IUT AM). IUT AM was organised early in the 1920s with the First Congress being held in Delft in 1924. The Euromech Colloquia were initiated some 20 years later with the intention of promoting European co-operation in the Mechanical Engineering Sciences. As the title implies, the Colloquium addressed a variety of problems associated with three main groups of materials, namely: high-strength composites, ceramics and cement-based materials, the common theme in each case being the relative brittleness of the matrix material. The problems considered ranged from fracture processes peculiar to such materials to projected design guidelines which will ensure their safe operation under a variety of conditions. Participants from thirteen countries (Czechoslovakia, France, FRG, GDR, Hungary, Italy, The Netherlands, Norway, Poland, Portugal, Sweden, UK, and USSR) contributed to the success of this event. For ease of reference, the 38 papers presented at the Colloquium have been subdivided into six distinct sections, viz. General Problems and Methods, Cracking in Ceramics, Fracture of Polymer Composites, Crack ing in Cement Based Composites, Fracture of Fibre Reinforced Cements and Fracture Mechanics of Concretes.

Download or read book Brittle Matrix Composites written by Mònica Ardanuy and published by Elsevier Inc. Chapters. This book was released on 2012-11-12 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work, the evaluation of the durability to wet-dry cycling exposure of cement composites reinforced with nanofibrillated cellulose comparing the results with composites reinforced with conventional cellulose fibres at the micro-scale level has been performed. For this purpose, cement mortar composites reinforced with cellulose fibres from conventional sisal pulp and cellulose nanofibres prepared by the application of a high intensity refining process have been prepared. The mechanical performance of the composites prepared was tested after 7 days of cure treatment and after 5 wet-dry cycles. The cement mortar composites reinforced with the nanofibrillated cellulose exhibited higher flexural strenght and flexural modulus but lower values of fracture energy than the ones reinforced with the conventional sisal fibres. No significant improvements of the durability were found for the composites prepared with nanofibrillated cellulose.

Download or read book Brittle Matrix Composites written by Alessandro P. Fantilli and published by Elsevier Inc. Chapters. This book was released on 2012-11-12 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new eco-mechanical index (EMI) has been introduced with the aim of quantifying the environmental impact of concrete structures. From a general point of view, this indicator represents the amount of carbon dioxide released to produce certain mixtures of pre-established strength and ductility. Both for normal strength and high strength concrete, with and without steel fibers, these mechanical properties are summarised by the work of fracture under tensile actions. If also structural durability has to be taken into account, the maximum crack width of reinforced concrete structures must be computed. This is possible by using a tension-stiffening model, here applied to reinforced concrete elements in tension. However, with or without the evaluation of crack width, the concrete with the best EMI releases the highest fracture energy. For this reason, the work of fracture represents also a durability parameter, and therefore it can be used to tailor cement-based composites with the highest strength, ductility, and durability, and the lowest environmental impact.