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Mit diesen Ausführungen wird ein Beitrag zum weiteren Erhalt der historischen Bausubstanz in Mecklenburg aus der Sicht der Tragwerksanalyse geleistet. Dabei bestätigt es sich immer mehr, dass mit dem Modell der Geometrie, der Belastung und des Materials gleichberechtigte Modelle für eine wirklichkeitsnahe Einschätzung des Tragverhaltens eines Tragwerks vorliegen müssen. Es zeigt sich, dass dabei die besten Berechnungsprogramme nur die Ergebnisse liefern können, die mit den Eingabedaten zu erzielen sind. So hat sich der Forschungsschwerpunkt im Lehrgebiet Tragwerkslehre des FB Architektur an der Hochschule Wismar in den letzten Jahren auf die realistische Abbildung der Wechselwirkung zwischen der Bauaufnahme und der geometrischen Modellierung konzentriert. In diesem Bereich zeigen sich als Schwerpunkte die Wechselwirkung zwischen Schäden und Tragwerksanalyse und die Wechselwirkung zwischen der aufgenommenen Geometrie und dem geometrischen Modell für die Tragwerksanalyse. Die Fülle der aufgenommenen Daten sind dabei in der Regel mehr hinderlich als ein Segen für die Tragwerksanalyse. Hier wurde gezeigt, welche und wie viele geometrische Daten für das geometrische Modell für die Tragwerksanalyse sinnvoll sind. Da die eigene Datenaufnahme relativ viel Zeit beansprucht, wurde eine "geistige" Bauaufnahme durchgeführt. Dazu wird der historische Planungsprozess in den einzelnen Formfindungsschritten nachvollzogen und in die virtuelle Realität überführt. Mit dieser Methode ergeben sich unterschiedliche Bauzustände und es lassen sich auch mögliche Bauphasen abbilden. Die Tragwerksanalyse dieser virtuellen Realität zeigt dann mögliche Schwächen der Tragwerke und/oder die Notwendigkeit konstruktiver Veränderungen. Ein Vergleich der Ergebnisse der Tragwerksanalyse mit der Realität anhand des vorliegenden Datenbestands liefert die Grundlage für den aktuellen Handlungsbedarf. Da der Bauzustand eines Bauwerkes unter einer zeitlichen Veränderung steht, werden Methoden überprüft, die es ermöglichen, einen einmal vorgelegten Datenbestand aufzubereiten und weiter zu verwalten.
The design of challenging space structures frequently relies on the theory of folded plates. The models are composed of plane facets of which the bending and membrane stiffness are coupled along the folds. In conventional finite element analysis of faceted structures the continuity of the displacement field is enforced exclusively at the nodes. Since approximate solutions for transverse and for in-plane displacements are not members of the same function space, separation occurs in between the common nodes of adjacent elements. It is shown that the kinematic assumptions of Bernoulli are accounted for this incompatibility along the edges in facet models. A general answer to this problem involves substantial modification of plate and membrane theory, but a straight forward formulation can be derived for simply folded plates, structures, whose folds do not intersect. A broad class of faceted structures, including models of various curved shells, belong to this category and can be calculated consistently. The additional requirements to assure continuity concern the mapping of displacement derivatives on the edges. An appropriate finite facet element provides node and edge-oriented degrees of freedom, whose transformation to system degrees of freedom, depends on the geometric configuration at each node. The concept is implemented using conform triangular elements. To evaluate the new approach, the energy norm of representative structures for refined meshes is calculated. The focus is placed on the mathematical convergence towards reliable solutions obtained from finite volume models.
The present study was designed to investigate the underlying factors determining the visual impressions of design-patterns that have complex textures. Design-patterns produced by "the dynamical system defined by iterations of discrete Laplacians on the plane lattice" were adopted as stimuli because they were not only complex, but also defined mathematically. In the experiment, 21 graduate and undergraduate students sorted 102 design-patterns into several groups by visual impressions. Those 102 patterns were classified into 12 categories by the cluster analysis. The results showed that the regularity of pattern was a most efficient factor for determining visual impressions of design-pattern, and there were some correspondence between visual impressions and mathematical variables of design-pattern. Especially, the visual impressions were influenced greatly by the neighborhood, and less influenced by steps of iterations.
This is an implementation of the Fillmore–Springer–Cnops construction (FSCc) based on the Clifford algebra capacities of the GiNaC computer algebra system. FSCc linearises the linear-fraction action of the Mobius group. This turns to be very useful in several theoretical and applied fields including engineering. The core of this realisation of FSCc is done for an arbitrary dimension, while a subclass for two dimensional cycles add some 2D-specific routines including a visualisation to PostScript files through the MetaPost or Asymptote software. This library is a backbone of many result published in, which serve as illustrations of its usage. It can be ported (with various level of required changes) to other CAS with Clifford algebras capabilities.
In diesem Beitrag wird eine mobile Software-Komponente zur Vor-Ort-Unterstützung von Bauwerksprüfungen gemäß DIN 1076 „Ingenieurbauwerke im Zuge von Strassen und Wegen, Überwachung und Prüfung“ vorgestellt, welche sich im praktischen Einsatz bei der Hochbahn AG Hamburg befindet. Mit Hilfe dieses Werkzeugs kann die Aktivität am Bauwerk in den gesamten softwaregestützten Geschäftsprozess der auwerksinstandhaltung integriert und somit die Bearbeitungszeit einer Bauwerksprüfung von der Vorbereitung bis zur Prüfbericht-Erstellung reduziert werden. Die Technologie des Mobile Computing wird unter Berücksichtigung spezieller fachlicher Randbedingungen, wie z.B. dem Einsatzort unter freiem Himmel, erläutert und es werden Methoden zur effizienten Datenerfassung mit Stift und Sprache vorgestellt und bewertet. Ferner wird die Einschränkung der Hardware durch die geringere Größe der Endgeräte, die sich durch die Bedingung der Mobilität ergibt, untersucht.
A concept for integrated modeling of urban and rural hydrology is introduced. The concept allows for simulations on the catchment scale as well as on the local scale. It is based on a 2-layer-approach which facilitates the parallel coupling of a catchment hydrology model with an urban hydrology model, considering the interactions between the two systems. The concept has been implemented in a computer model combining a grid based distributed hydrological catchment model and a hydrological urban stormwater model based on elementary units. The combined model provides a flexible solution for time and spatial scale integration and offers to calculate separate water balances for urban and rural hydrology. Furthermore, it is GIS-based which allows for easy and accurate geo-referencing of urban overflow structures, which are considered as points of interactions between the two hydrologic systems. Due to the two-layer-approach, programs of measures can be incorporated in each system separately. The capabilities of the combined model have been tested on a hypothetical test case and a real world application. It could be shown that the model is capable of accurately quantifying the effects of urbanization in a catchment. The affects of urbanization can be analyzed at the catchment outlet, but can also be traced back to its origins, due to the geo-referencing of urban overflow structures. This is a mayor advantage over conventional hydrological catchment models for the analysis of land use changes.
For assessment of old buildings, thermal graphic analysis aided with infra-red camera have been employed in a wide range nowadays. Image processing and evaluation can be economically practicable only if the image evaluation can also be automated to the largest extend. For that reason methods of computer vision are presented in this paper to evaluate thermal images. To detect typical thermal image elements, such as thermal bridges and lintels in thermal images respectively gray value images, methods of digital image processing have been applied, of which numerical procedures are available to transform, modify and encode images. At the same time, image processing can be regarded as a multi-stage process. In order to be able to accomplish the process of image analysis from image formation through perfecting and segmentation to categorization, appropriate functions must be implemented. For this purpose, different measuring procedures and methods for automated detection and evaluation have been tested.
The Lucas-Kanade tracker has proven to be an efficient and accurate method for calculation of the optical flow. However, this algorithm can reliably track only suitable image features like corners and edges. Therefore, the optical flow can only be calculated for a few points in each image, resulting in sparse optical flow fields. Accumulation of these vectors over time is a suitable method to retrieve a dense motion vector field. However, the accumulation process limits application of the proposed method to fixed camera setups. Here, a histogram based approach is favored to allow more than a single typical flow vector per pixel. The resulting vector field can be used to detect roads and prescribed driving directions which constrain object movements. The motion structure can be modeled as a graph. The nodes represent entry and exit points for road users as well as crossings, while the edges represent typical paths.
This paper presents two new methods for analysis of a technical state of large-panel residential buildings. The first method is based on elements extracted from the classical methods and on data about repairs and modernization collected from building documentations. The technical state of a building is calculated as a sum of several groups of elements defining the technical state. The deterioration in this method depends on: - time, which has passed since last repair of element or time which has passed since construction, - estimate of the state of element groups which can be determined on basis of yearly controls. This is a new unique method. it is easy to use, does not need expertise. The required data could be extracted easily from building documentations. For better accuracy the data from building inspections should be applied (in Poland inspections are made every year). The second method is based on the extracted data processing by means of the artificial neural networks. The aim is to learn the artificial neural network configurations for a set of data containing values of the technical state and information about building repairs for last years (or other information and building parameters) and next to analyse new buildings by the instructed neural network. The second profit from using artificial neural networks is the reduction of number of parameters. Instead of more then 40 parameters describing building, about 6-12 are usually sufficient for satisfactory accuracy. This method could have lower accuracy but it is less prone to data errors.
Procedures of a construction of general solutions for some classes of partial differential equations (PDEs) are proposed and a symmetry operators approach to the raising the orders of the polynomial solutions to linear PDEs are develops. We touch upon an ''operator analytic function theory'' as the solution of a frequent classes of the equations of mathematical physics, when its symmetry operators forms vast enough space. The MAPLE© package programs for the building the operator variables is elaborated also.
We show a close relation between the Schrödinger equation and the conductivity equation to a Vekua equation of a special form. Under quite general conditions we propose an algorithm for explicit construction of pseudoanalytic positive formal powers for the Vekua equation that as a consequence gives us a complete system of solutions for the Schrödinger and the conductivity equations. Besides the construction of complete systems of exact solutions for the above mentioned second order equations and the Dirac equation, we discuss some other applications of pseudoanalytic function theory.
Interval analysis extends the concept of computing with real numbers to computing with real intervals. As a consequence, some interesting properties appear, such as the delivery of guaranteed results or confirmed global values. The former property is given in the sense that unknown numerical values are in known to lie in a computed interval. The latter property states that the global minimum value, for example, of a given function is also known to be contained in a interval (or a finite set of intervals). Depending upon the amount computation effort invested in the calculation, we can often find tight bounds on these enclosing intervals. The downside of interval analysis, however, is the mathematically correct, but often very pessimistic size of the interval result. This is in particularly due to the so-called dependency effect, where a single variable is used multiple times in one calculation. Applying interval analysis to structural analysis problems, the dependency has a great influence on the quality of numerical results. In this paper, a brief background of interval analysis is presented and shown how it can be applied to the solution of structural analysis problems. A discussion of possible improvements as well as an outlook to parallel computing is also given.
In civil engineering practice, values of column forces are often required before any detailed analysis of the structure has been performed. One of the reasons for this arises from the fast-tracked nature of the majority of construction projects: foundations are laid and base columns constructed whilst analysis and design are still in progress. A need for quick results when feasibility studies are performed or when evaluating the effect of design changes on supporting columns form other situations in which column forces are required, but where a detailed analysis to get these forces seems superfluous. Thus it was concluded that the development of an efficient tool for column force calculations, in which the extensive input required in a finite element analysis is to be avoided, would be highly beneficial. The automation of the process is achieved by making use of a Voronoi diagram. The Voronoi diagram is used a) for subdividing the floor into influence areas and b) as a basis for automatic load assignment. The implemented procedure is integrated into a CAD system in which the relevant geometric information of the floor, i.e. its shape and column layout, can be defined or uploaded. A brief description of the implementation is included. Some comparative results and considerations regarding the continuation of the study are given.
This research focuses on an approach to describe principles in architectural layout planning within the domain of revitalization. With the aid of mathematical rules, which are executed by a computer, solutions to design problems are generated. Provided that "design" is in principle a combinatorial problem, i.e. a constraint-based search for an overall optimal solution of a problem, an exemplary method will be described to solve such problems in architectural layout planning. To avoid conflicts relating to theoretical subtleness, a customary approach adopted from Operations Research has been chosen in this work. In this approach, design is a synonym for planning, which could be described as a systematic and methodical course of action for the analysis and solution of current or future problems. The planning task is defined as an analysis of a problem with the aim to prepare optimal decisions by the use of mathematical methods. The decision problem of a planning task is represented by an optimization model and the application of an efficient algorithm in order to aid finding one or more solutions to the problem. The basic principle underlying the approach presented herein is the understanding of design in terms of searching for solutions that fulfill specific criteria. This search is executed by the use of a constraint programming language.
At the 16th IKM Bock, Falcão and Gürlebeck presented examples of the application of some specially developed Maple-Software in hypercomplex analysis. Other papers of those authors continued this work and showed the efficiency of such tools for concrete numerical calculations as well as for numerical experiments, supporting the detection of new relationships and even theorems in a highly technical theoretical work. The mentioned software has been developed mainly for the use on mapping problems in the Euclidean spaces of dimension 3 and 4 by means of Bergman kernel methods (BKM), which are related to monogenic functions as solutions of generalized Cauchy-Riemann equations with respect to the Euclidean metric (Riesz system). The developed procedures concerning generalized powers of totally regular variables and the corresponding homogeneous polynomials basically rely on results and conventions introduced in the paper "Power series representation for monogenic functions in Rm+1 based on a permutational product", Complex Variables, 15, No.3, 181-191 (1990) by H. Malonek. Since 1992 H. Leutwiler, S. L. Eriksson and others developed in a number of papers a modified Clifford analysis and, particularly, a modified quaternionic analysis. The modification mainly consists in considering generalized Cauchy-Riemann equations with respect to a hyperbolic metric in a half space. The aim of this contribution is to show how through a change of the basic combinatorial relations used in the modified quaternionic analysis the aforementioned Maple-software (that has been recently published on CD-Rom as integrated part of the text book "Funktionentheorie in der Ebene und im Raum" by K. Gürlebeck, K. Habetha, and W. Sprössig, in the series "Grundstudium Mathematik" of Birkhäuser Verlag, 2006) can directly be used for numerical calculations in the modified theory.
A new application of software technology is the application area of smart living or sustainable living. Within this area application platforms are designed and realized with the goal to support value added services. In this context value added services integrates microelectronics, home automation and services to enhance the attractiveness of flats, homes and buildings. Especially real estate companies or service providers dealing with home services are interested in an effective design and management of their services. Service Engineering is the approved approach for designing customer oriented service processes. Service engineering consists of several phases; from situation analysis to service creation and service design to service management. This article will describe how the method service blueprint can be used to design service processes. Smart living includes all actions to enlarge a flat to a smart home for living. One special requirement of this application domain is the use of local components (actuators, sensors) within service processes. This article will show how this extended method supports service providers to improve the quality of customer oriented service processes and the derivation of needed interfaces of involved actors. For the civil engineering process it will be possible to derive needed information from a built in home automation system. The aim is to show, how to get needed smart local components to fullfill later offered it-supported value added services. Value added services focused on inhabitants are grouped to consulting and information, care and supervision, leisure time activities, repairs, mobility and delivery, safety and security, supply and disposal.
Requires for reliability and durability of structures and their elements with simultaneous material economy have stimulated improvement of constitutive equations for description of elasto-plastic deformation processes. This has led to the development of phenomenological modelling of complex phenomena of irreversible deformation including history-dependent and rate-dependent effects. During the last several decades many works have been devoted to the development of elasto-plastic models, in order to better predict the material behavior under combined variable thermo-mechanical loading. The increase of accuracy of stress analysis and safety factors for complex structures with the help of modern finite-element packages (ABAQUS, ANSYS, COSMOS, LS-DYNA, MSC.MARC, MSC.NASTRAN, PERMAS and other) can be provided only by use of complex and special variants of plasticity theories, which are adequate for the considered loading conditions and based on authentic information about properties of materials. The areas of application of the various theories (models) are as a rule unknown to the users of finite-element packages at the existing variety loading condition sin machine-building designs. At the moment a universal theory of inelasticity is absent and even the most accomplished theories can not guarantee adequate description of deformation processes for arbitrary structure under wide range of loading programs. The classifier of materials, loading conditions, effects (phenomena) and list of basic experiments are developed by the authors. Use of these classifiers for an establishment of hierarchy of models is a first step for introduction of the multimodel analysis into computational practice. The set of the classic and modern inelasticity theories is considered, so that they are applicable for stress analysis of structures under complex loading programs. Among them there are plastic flow theories with linear and nonlinear isotropic and kinematic hardening, multisurface theories, endochronic theory, holonomic theory, rheologic models, theory of elasto-plastic processes, slip theory, physical theories (single crystal and polycrystalline models) and others. The classification of materials provides rearranging by a degree of homogeneous, chemical composition, level of strength and plasticity, behavior under cyclic loading, anisotropy of properties at initial condition, anisotropy of properties during deformation process, structural stability. The classification of loading conditions takes into consideration proportional and non-proportional loading, temperature range, combination of cyclic and monotonous loading, one-axial, two-axial and complex stress state, curvature of strain path, presence of stress concentrators and level of strain gradient. A unified general form of constitutive equations is presented for all used material models based upon the concept of internal state variables. The wide range of mentioned above inelastic material models has been implemented into finite element program PANTOCRATOR developed by authors (see for details www.pantocrator.narod.ru). Application possibility of different material models is considered both for material element and for complex structures subjected to complex non-proportional loading.
The paper is devoted to the investigation of dynamical behavior of a cable under influence of various types of excitations. Such element has a low rigidity and is sensitive to dynamic effect. The structural scheme is a cable which ends are located at different level. The analysis of dynamical behavior of the cable under effect of kinematical excitation which is represented by the oscillations of the upper part of tower is given. The scheme of cable is accepted such, that lower end of an inclined cable is motionless. The motion of the upper end is assumed only in horizontal direction. The fourth-order Runge-Kutta method was realized in software. The fast Fourier transform was used for spectral analysis. Standard graphical software was adopted for presenting results of investigations. The mathematical model of oscillations of a cable was developed by the account of the viscous damping. The analysis of dynamical characteristics of a cable for various parameters of damping and kinematical excitation was carried out. The time series, spectral characteristics and amplitude-frequencies characteristics was obtained. The resonance amplitude for different oscillating regimes was estimated. It is noted that increasing of the coefficient of the viscous damping and decreasing of the amplitude of tower's oscillations reduces the value of the critical frequency and the resonant amplitudes.
This paper deals with the development of a new multi-objective evolution strategy in combination with an integrated pollution-load and water-quality model. The optimization algorithm combines the advantages of the Non-Dominated Sorting Genetic Algorithm and Self-Adaptive Evolution Strategies. The identification of a good spread of solutions on the pareto-optimum front and the optimization of a large number of decision variables equally demands numerous simulation runs. In addition, statements with regard to the frequency of critical concentrations and peak discharges require continuous long-term simulations. Therefore, a fast operating integrated simulation model is needed providing the required precision of the results. For this purpose, a hydrological deterministic pollution-load model has been coupled with a river water-quality and a rainfall-runoff model. Wastewater treatment plants are simulated in a simplified way. The functionality of the optimization and simulation tool has been validated by analyzing a real catchment area including sewer system, WWTP, water body and natural river basin. For the optimization/rehabilitation of the urban drainage system, both innovative and approved measures have been examined and used as decision variables. As objective functions, investment costs and river water quality criteria have been used.
The paper is a proposal of calculation of internal forces and dislocations in the reinforced concrete beams before and after cracking. For the ideally elastic bars transfer matrix proposed by Rakowski was applied. The effects associated with cracking were introduced by means of the Borcz's theory in the spectrally way. Numerical example was shown. The presented attitude also enables to calculate dynamic problems and those connected with the stability of the compressed and bending cracked beams and columns.