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Structural control is an approach aimed at the suppressing unwanted
dynamic phenomena in civil structures. It proposes the use of
methods and tools from control theory for the analysis and
manipulation of a structure’s dynamic behavior, with emphasis on
suppression of seismic and wind responses. This book addresses
problems in optimal structural control. Its goal is to provide
solutions and techniques for these problems by using optimal
control theory. Thus, it deals with the solution of optimal control
design problems related to passive and semi-active controlled
structures. The formulated problems consider constraints and
excitations which are common in structural control. Optimal control
theory is used in order to solve these problems in a rigorous
manner. Even though there are many works in this field, none
comprise optimization techniques with firm theoretical background
that address the solution of passive and semi-active structural
control design problems. The book begins with a discussion on
models which are commonly used for civil structures and control
actuators. Modern theoretical notions, such as dissipativity and
passivity of dynamic systems are discussed in context of the
addressed problems. Optimal control theory and suitable successive
methods are reviewed. Novel solutions for optimal passive and
semi-active control design problems are derived, based on firm
theoretical foundations. These results are verified by numerical
simulations of typical civil structures which are subjected to
different types of dynamic excitations.
Concrete and reinforced concrete remain the main building materials
for construction of modern fortifications. The book presents
experimental and theoretical results allowing production of special
high-strength rapid hardening concrete and fiber reinforced
concrete. It describes a method for effective proportioning of
high-strength fast-setting concrete and fiber reinforced concrete
with high dynamic strength as well as selecting proper
technological parameters, methodology for design of reinforced
concrete structures using such concrete. Particular attention is
paid to ensuring the early strengthening of concrete within 24
hours after casting and to constructing structures with limited
energy resources at the site.
The book deals with modern theoretical concepts related to the
impact of fly ash and metakaolin admixtures on structure formation
processes of concrete. Results of the effect of fly ash, metakaolin
and their composition on properties of self-compacting and
self-leveling concrete are presented. Based on mathematical models,
obtained using mathematical experiments planning methodology, the
impact of the main factors and their combination on workability,
strength and other properties that determine efficiency and
durability of concrete are analyzed. Using calculated dependencies,
a methodology for designing optimal compositions of concrete
containing active mineral admixtures and superplasticizers is
proposed. Features of industrial production of concrete for the
proposed compositions are discussed. The book is intended for
specialists working in the production of concrete and reinforced
concrete products and elements. It can also be used by construction
engineers to design compositions of cost-effective self-compacting
and self-leveling concrete as well as to determine the rational
direction of using technogenic raw materials like ash and
metakaolin.
Structural control is an approach aimed at the suppressing unwanted
dynamic phenomena in civil structures. It proposes the use of
methods and tools from control theory for the analysis and
manipulation of a structure's dynamic behavior, with emphasis on
suppression of seismic and wind responses. This book addresses
problems in optimal structural control. Its goal is to provide
solutions and techniques for these problems by using optimal
control theory. Thus, it deals with the solution of optimal control
design problems related to passive and semi-active controlled
structures. The formulated problems consider constraints and
excitations which are common in structural control. Optimal control
theory is used in order to solve these problems in a rigorous
manner. Even though there are many works in this field, none
comprise optimization techniques with firm theoretical background
that address the solution of passive and semi-active structural
control design problems. The book begins with a discussion on
models which are commonly used for civil structures and control
actuators. Modern theoretical notions, such as dissipativity and
passivity of dynamic systems are discussed in context of the
addressed problems. Optimal control theory and suitable successive
methods are reviewed. Novel solutions for optimal passive and
semi-active control design problems are derived, based on firm
theoretical foundations. These results are verified by numerical
simulations of typical civil structures which are subjected to
different types of dynamic excitations.
The monograph analyses the state of the art (problem) in using
stone siftings and aspiration dust obtained in natural stone
crushing for producing concrete aggregates and fillers for dry
construction mixtures and mortars on their basis. The influence of
disperse fraction in stone siftings and aspiration dust on
structural, mechanical and rheological properties of cement
composite construction materials is investigated. Hypothesis for
obtaining technological conditions, providing positive effect of
the disperse fraction on strength and other properties of cement
based concrete and mortar is proposed. Experimental results on
studying properties of dry mixtures and mortars on their basis
using stone crushing aspiration dust as filler are presented.
Efficiency of using fillers, based on igneous rocks, on adhesive
and other properties of mortars is demonstrated. Methodology for
design of mortars composition for given mortar properties in case,
when aspiration dust is used as filler, is proposed. The monograph
presents experimental results on fine-grained concrete including as
a main filler stone siftings with up to 20% of disperse fraction.
It is shown that it is possible to produce fine grain concrete
class 20/25... 60/75. Technological parameters of vibro-pressed
fine-grained concrete with raw stone siftings are developed.
Methodologies for composition design of fine-grained concrete with
given workability are proposed. Possibility for producing
macroporous light-weight concrete for walls and filtration
materials, based on stone siftings fillers is shown.
One of the main goals of a good and effective structural design is
to decrease, as far as possible, the self-weight of structures,
because they must carry the service load. This is especially
important for reinforced concrete (RC) structures, as the
self-weight of the material is substantial. For RC structures it is
furthermore important that the whole structure or most of the
structural elements are under compression with small
eccentricities. Continuous spatial concrete structures satisfy the
above-mentioned requirements. It is shown in this book that a span
of a spatial structure is practically independent of its thickness
and is a function of its geometry. It is also important to define
which structure can be called a spatial one. Such a definition is
given in the book and based on this definition, five types of
spatial concrete structures were selected: translation shells with
positive Gaussian curvature, long convex cylindrical shells,
hyperbolic paraboloid shells, domes, and long folders. To
demonstrate the complex research, results of experimental,
analytical, and numerical evaluation of a real RC dome are
presented and discussed. The book is suitable for structural
engineers, students, researchers and faculty members at
universities.
The monograph analyses the state of the art (problem) in using
stone siftings and aspiration dust obtained in natural stone
crushing for producing concrete aggregates and fillers for dry
construction mixtures and mortars on their basis. The influence of
disperse fraction in stone siftings and aspiration dust on
structural, mechanical and rheological properties of cement
composite construction materials is investigated. Hypothesis for
obtaining technological conditions, providing positive effect of
the disperse fraction on strength and other properties of cement
based concrete and mortar is proposed. Experimental results on
studying properties of dry mixtures and mortars on their basis
using stone crushing aspiration dust as filler are presented.
Efficiency of using fillers, based on igneous rocks, on adhesive
and other properties of mortars is demonstrated. Methodology for
design of mortars composition for given mortar properties in case,
when aspiration dust is used as filler, is proposed. The monograph
presents experimental results on fine-grained concrete including as
a main filler stone siftings with up to 20% of disperse fraction.
It is shown that it is possible to produce fine grain concrete
class 20/25... 60/75. Technological parameters of vibro-pressed
fine-grained concrete with raw stone siftings are developed.
Methodologies for composition design of fine-grained concrete with
given workability are proposed. Possibility for producing
macroporous light-weight concrete for walls and filtration
materials, based on stone siftings fillers is shown.
One of the main goals of a good and effective structural design is
to decrease, as far as possible, the self-weight of structures,
because they must carry the service load. This is especially
important for reinforced concrete (RC) structures, as the
self-weight of the material is substantial. For RC structures it is
furthermore important that the whole structure or most of the
structural elements are under compression with small
eccentricities. Continuous spatial concrete structures satisfy the
above-mentioned requirements. It is shown in this book that a span
of a spatial structure is practically independent of its thickness
and is a function of its geometry. It is also important to define
which structure can be called a spatial one. Such a definition is
given in the book and based on this definition, five types of
spatial concrete structures were selected: translation shells with
positive Gaussian curvature, long convex cylindrical shells,
hyperbolic paraboloid shells, domes, and long folders. To
demonstrate the complex research, results of experimental,
analytical, and numerical evaluation of a real RC dome are
presented and discussed. The book is suitable for structural
engineers, students, researchers and faculty members at
universities.
This book focuses on the challenges of academic teaching in an era
of technological advances. The challenges of pedagogy and
technology are an important topic in the debates of academic
scholars on the instructor's role in an era of technological
progress. Have lecturers become obsolete? Will the classroom become
a studio setting in which lectures will be broadcast? What is the
role of collaboration in creating a multi-campus virtual university
where the best lecturers teach and share their knowledge? What are
the implications of the new options created through the mediation
of lecturers' teaching materials? What are the implications for
teaching practice and the learning experience, and what are the
social, ethical, moral, and financial implications and the
implications for infrastructure and policy-making? The contributing
authors, researchers and educators from diverse disciplines and
research institutions offer a fresh perspective on the changing
face of teaching in higher education and its responses to
contemporary challenges.
This book deals with the challenges of academic teaching in higher
education with regard to quality, mobility, and globalisation. The
articles reflect a unique interdisciplinary effort at
collaboration, generated by colleagues and partners who joined
together to form a community that aimed to chart the course of
academic teaching. The book is divided into five parts: Part One -
Academic teaching and learning; Part Two - Academic teaching and
learning in the humanities; Part Three - Teaching and learning in
engineering and architecture; Part Four - New approaches and
technologies in physics instruction: Inquiry-based education in a
post-industrial society; Part Five - Teaching and learning in the
health sciences.
This monograph analyses experimental and theoretical investigations
in the field of reinforced concrete structures and elements from
the viewpoint of a new mini-max principle and application of this
principle for calculation of forces, strengths and critical
buckling loads in RC shells, columns, plates, etc. The basis of the
mini-max principle was developed during solving a problem of
finding an RC shell load bearing capacity via a kinematic method.
Forming the internal forces' fields at the plastic stage of the
structure leads to a problem, related to interaction between the
normal forces and bending moments, but at this stage the compressed
shell section has an unknown eccentricity. Therefore an additional
equation should be found for separating the above-mentioned forces.
The following idea was proposed: the section compressed zone depth
(static parameter) should be selected so that the maximum load
bearing capacity of the structure is realized simultaneously with
minimizing the external load the failure zone dimension (kinematic
parameter). Development of this idea resulted in formulating the
mini-max principle. The essence of this principle is that real load
bearing capacity of the structure is calculated (without under- and
over-estimation). With this aim it is proposed to use in the same
calculation both extreme features of failure load. At the same time
just one method is used (static or kinematic). Thus, the mini-max
principle became a way for realizing the unity theorem of the limit
equilibrium method, which joints the static and kinematic
approaches. The mini-max principle enabled to solve some problems
in load bearing capacity of structures that had no solutions or
were solved approximately. Additionally, the principle was used for
solving some new problems in calculation of RC shells.
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