56.03 Methoden im Bauingenieurwesen
Refine
Document Type
- Article (143) (remove)
Institute
Keywords
- Bautechnik (21)
- Produktmodell (20)
- Simulation (20)
- Finite-Elemente-Methode (17)
- Lernendes System (15)
- Mehragentensystem (14)
- Modellierung (13)
- Physikalisches Verfahren (11)
- Bauwerk (9)
- CAD (8)
Efforts to define standards for representing AEC/FM data have been fairly successful. However defining a standard reference process model has not met with the same success. Yet almost every conceptual modelling or software development project starts by defining the business processes to be supported and the related requirements to be satisfied. This paper describes a new process-centred methodology for user requirements capture developed in the ICCI project (IST-2001-33022). Its essence is in recognising user requirements and use cases in the context of the real construction process, identifying the actors and roles for each individual activity and associating these activities with information, communication and standardisation requirements on the basis of a formalised specification, named the Process Matrix. In the paper we outline the history of process matrix development, introduce the basic structure of the matrix and show how it can be further extended and refined. We present also a web-based software implementation of the developed approach, describe how it has been used in ICCI and outline further perspectives.
Thin elastic plates are the basic constructional elements and are very often subjected to dynamic effects especially in the machine-building structures. Their saving design of resonance conditions of operation is an extremely complicated task which cannot be solved analytically. In the present report an efficient and sufficiently general method for optimal design of thin plates is worked out on the basis of energy resonance method of Wilder, the method of the finite elements for dynamic research and the methods of parameter optimization. By means of these methods various limitations and requirements put by the designer to the plates can be taken into account. A programme module for numerical investigation of the weight variation of the plate depending on the taken variable of the designed thickness at different supporting conditions is developed. The reasons for the considerable quantity and quality difference between the obtained optimal designs are also analysed.
Current disaster management procedures rely primarily on heuristics which result in their strategies being very cautious and sub-optimum in terms of saving life, minimising damage and returning the building to its normal function. Also effective disaster management demands decentralized, dynamic, flexible, short term and across domain resource sharing, which is not well supported by existing distributing computing infrastructres. The paper proposes a conceptual framework for emergency management in the built environment, using Semantic Grid as an integrating platform for different technologies. The framework supports a distributed network of specialists in built environment, including structural engineers, building technologists, decision analysts etc. It brings together the necessary technology threads, including the Semantic Web (to provide a framework for shared definitions of terms, resources and relationships), Web Services (to provide dynamic discovery and integration) and Grid Computing (for enhanced computational power, high speed access, collaboration and security control) to support rapid formation of virtual teams for disaster management. The proposed framework also make an extensive use of modelling and simulation (both numerical and using visualisations), data mining (to find resources in legacy data sets) and visualisation. It also include a variety of hardware instruments with access to real time data. Furthermore the whole framework is centred on collaborative working by the virtual team. Although focus of this paper is on disaster management, many aspects of the discussed Grid and Visualisation technologies will be useful for any other forms of collaboration. Conclusions are drawn about the possible future impact on the built environment.
Für eine Abschätzung des Heizwärmebedarfs von Gebäuden und Quartieren können thermisch-energetische Simulationen eingesetzt werden. Grundlage dieser Simulationen sind geometrische und physikalische Gebäudemodelle. Die Erstellung des geometrischen Modells erfolgt in der Regel auf Basis von Bauplänen oder Vor-Ort-Begehungen, was mit einem großen Recherche- und Modellierungsaufwand verbunden ist. Spätere bauliche Veränderungen des Gebäudes müssen häufig manuell in das Modell eingearbeitet werden, was den Arbeitsaufwand zusätzlich erhöht. Das physikalische Modell stellt die Menge an Parametern und Randbedingungen dar, welche durch Materialeigenschaften, Lage und Umgebungs-einflüsse gegeben sind. Die Verknüpfung beider Modelle wird innerhalb der entsprechenden Simulations-software realisiert und ist meist nicht in andere Softwareprodukte überführbar. Mithilfe des Building Information Modeling (BIM) können Simulationsdaten sowohl konsistent gespeichert als auch über Schnittstellen mit entsprechenden Anwendungen ausgetauscht werden. Hierfür wird eine Methode vorgestellt, die thermisch-energetische Simulationen auf Basis des standardisierten Übergabe-formats Industry Foundation Classes (IFC) inklusive anschließender Auswertungen ermöglicht. Dabei werden geometrische und physikalische Parameter direkt aus einem über den gesamten Lebenszyklus aktuellen Gebäudemodell extrahiert und an die Simulation übergeben. Dies beschleunigt den Simulations-prozess hinsichtlich der Gebäudemodellierung und nach späteren baulichen Veränderungen. Die erarbeite-te Methode beruht hierbei auf einfachen Modellierungskonventionen bei der Erstellung des Bauwerksinformationsmodells und stellt eine vollständige Übertragbarkeit der Eingangs- und Ausgangswerte sicher.
Thermal building simulation based on BIM-models. Thermal energetic simulations are used for the estimation of the heating demand of buildings and districts. These simulations are based on building models containing geometrical and physical information. The creation of geometrical models is usually based on existing construction plans or in situ assessments which demand a comparatively big effort of investigation and modeling. Alterations, which are later applied to the structure, request manual changes of the related model, which increases the effort additionally. The physical model represents the total amount of parameters and boundary conditions that are influenced by material properties, location and environmental influences on the building. The link between both models is realized within the correspondent simulation soft-ware and is usually not transferable to other software products. By Applying Building Information Modeling (BIM) simulation data is stored consistently and an exchange to other software is enabled. Therefore, a method which allows a thermal energetic simulation based on the exchange format Industry Foundation Classes (IFC) including an evaluation is presented. All geometrical and physical information are extracted directly from the building model that is kept up-to-date during its life cycle and transferred to the simulation. This accelerates the simulation process regarding the geometrical modeling and adjustments after later changes of the building. The developed method is based on simple conventions for the creation of the building model and ensures a complete transfer of all simulation data.
Für eine Abschätzung des Heizwärmebedarfs von Gebäuden und Quartieren können thermisch-energetische Simulationen eingesetzt werden. Grundlage dieser Simulationen sind geometrische und physikalische Gebäudemodelle. Die Erstellung des geometrischen Modells erfolgt in der Regel auf Basis von Bauplänen oder Vor-Ort-Begehungen, was mit einem großen Recherche- und Modellierungsaufwand verbunden ist. Spätere bauliche Veränderungen des Gebäudes müssen häufig manuell in das Modell eingearbeitet werden, was den Arbeitsaufwand zusätzlich erhöht. Das physikalische Modell stellt die Menge an Parametern und Randbedingungen dar, welche durch Materialeigenschaften, Lage und Umgebungs-einflüsse gegeben sind. Die Verknüpfung beider Modelle wird innerhalb der entsprechenden Simulations-software realisiert und ist meist nicht in andere Softwareprodukte überführbar.
Mithilfe des Building Information Modeling (BIM) können Simulationsdaten sowohl konsistent gespeichert als auch über Schnittstellen mit entsprechenden Anwendungen ausgetauscht werden. Hierfür wird eine Methode vorgestellt, die thermisch-energetische Simulationen auf Basis des standardisierten Übergabe-formats Industry Foundation Classes (IFC) inklusive anschließender Auswertungen ermöglicht. Dabei werden geometrische und physikalische Parameter direkt aus einem über den gesamten Lebenszyklus aktuellen Gebäudemodell extrahiert und an die Simulation übergeben. Dies beschleunigt den Simulations-prozess hinsichtlich der Gebäudemodellierung und nach späteren baulichen Veränderungen. Die erarbeite-te Methode beruht hierbei auf einfachen Modellierungskonventionen bei der Erstellung des Bauwerksinformationsmodells und stellt eine vollständige Übertragbarkeit der Eingangs- und Ausgangswerte sicher.
Thermal building simulation based on BIM-models. Thermal energetic simulations are used for the estimation of the heating demand of buildings and districts. These simulations are based on building models containing geometrical and physical information. The creation of geometrical models is usually based on existing construction plans or in situ assessments which demand a comparatively big effort of investigation and modeling. Alterations, which are later applied to the structure, request manual changes of the related model, which increases the effort additionally. The physical model represents the total amount of parameters and boundary conditions that are influenced by material properties, location and environmental influences on the building. The link between both models is realized within the correspondent simulation soft-ware and is usually not transferable to other software products.
By Applying Building Information Modeling (BIM) simulation data is stored consistently and an exchange to other software is enabled. Therefore, a method which allows a thermal energetic simulation based on the exchange format Industry Foundation Classes (IFC) including an evaluation is presented. All geometrical and physical information are extracted directly from the building model that is kept up-to-date during its life cycle and transferred to the simulation. This accelerates the simulation process regarding the geometrical modeling and adjustments after later changes of the building. The developed method is based on simple conventions for the creation of the building model and ensures a complete transfer of all simulation data.
The purpose of this paper is to review model for finite element techniques for non-linear crack analysis of reinforced concrete beams and slabs. The non-linear behaviour of concrete and steel were described. Some calculations of >self-stress< for concrete and reinforced concrete beam was made. Current computational aspects are discussed. Several remarks for future studies are also given. The numerical model of the concrete and reinforced concrete was described. The paper shows the results of calculations on a reinforced concrete plane stress panel with cracks. The non-linear, numerical model of calculations of reinforced concrete was assumed. Using finite elements method some calculations were made. The results of calculations like displacements, stresses and cracking are shown on diagrams. They were compared with experimental results and other finding. Some conclusions about the described model and results of calculation are shown.
In the abstract proposed is the Instrumental System of mechanics problems analysis of the deformed solid body. It supplies the researcher with the possibility to describe the input data on the object under analyses and the problem scheme based upon the variational principles within one task. The particular feature of System is possibility to describe the information concerning the object of any geometrical shape and the computation sheme according to the program defined for purpose. The Methods allow to compute the tasks with indefinite functional and indefinite geometry of the object (or the set of objects). The System provides the possibility to compute the tasks with indefinite sheme based upon the Finite Element Method (FEM). The restrictions of the System usage are therefore determined by the restrictions of the FEM itself. It contrast to other known programms using FEM (ANSYS, LS-DYNA and etc) described system possesses more universality in defining input data and choosing computational scheme. Builtin is an original Subsytem of Numerical Result Analuses. It possesses the possibility to visualise all numerical results, build the epures of the unknown variables, etc. The Subsystem is approved while solving two- and three-dimensional problems of Elasticiti and Plasticity, under the conditions of Geometrical Unlinearity. Discused are Contact Problems of Statics and Dynamics.
In this paper the results of the investigations of the free oscillations of the pre-stressed flexible structure elements are presented . Two cases of the central preliminary stress are investigated : without intermediate fastening of the tie to the flexible element and with the intermediate fastening in the middle of the element length. The given physical model can be applied to the flexible sloping shells and arches, membranes, large space antenna fields (besides flexible elements). The peculiarity of these systems is the possibility of the non-adjacent equilibrium form existence at the definite relations of the physical parameters . The transition from one stable equilibrium form to another, non-adjacent form, may be treated as jump. In this case they are called systems with buckling or the systems with two potential «gaps». These systems commenced the new section of the mathematical physics - the theory of chaos and strange attractors. The analysis of the solutions confirms the received for the first time by the author and given in effect of the oscillation period doubling of the system during the transition from the «small» oscillations relatively center to the >large< relatively all three equilibrium conditions. The character of the frequency (period) dependence on the free oscillation amplitudes of the non-linear system also confirms the received earlier result of the duality of the system behaviour : >small< oscillations possess the qualities of soft system; >large< oscillations possess the qualities of rigid system. The >small< oscillation natural frequency changing, depending on the oscillation amplitudes, is in the internal . Here the frequency takes zero value at the amplitude values Aa and Ad (or Aa and Ae ); the frequency takes maximum value at the amplitude value near point b .The >large< oscillation natural frequency changes in the interval . Here is also observed . The influence of the tie intermediate fastening doesn't introduce qualitative changes in the behaviour of the investigated system. It only increases ( four times ) the critical value of the preliminary tension force
In the design of a structure, the implementation of reliable soil-foundation-structure interaction into the analysis process plays a very important role. The paper presents a determination of parameters of a suitably chosen soil-foundation model and their influence on the structure response. Since the mechanical data for the structure can be determined with satisfactory accuracy, the properties of the soil-foundation model were identified using measured dynamic response of the real structure. A simple model describing soil-foundation structure was incorporated into the classical 3-D finite element analysis of the structure with commercial software. Results obtained from the measured data on the pier were afterwards compared with those obtained with the finite model of the pier-foundation-soil structure. On the basis of this comparison the coefficients describing the properties in the soil-foundation model were adjusted until the calculated dynamic response coincided with the measured ones. In this way, the difference between both results was reduced to 1%. Full-scale tests measuring eigenmotion of the bridge were performed through all erection stages of the new bridge in Maribor. In this way an effective and experimentally verified 3-D model for a complex dynamic analysis of the bridge under the earthquake loading was obtained. The significant advantage of the obtained model is that it was updated on the basis of the dynamic measurements thus improving the model on the basis of in-situ geomechanical measurements. The model is very accurate in describing the upper structure and economical in describing the soil mass thus representing an optimal solution regarding computational efforts.
In the given paper the generalized formulation of the problem of computer modelling of the complex-composite structure interaction with different types of dynamic loads and effects is discussed. Here the analysis is given as for the usage of some universal computing systems for the solution of such problems. Also if is shown that the quantification of the dynamic models of the complex-composite systems with the variable structure, depending on the character and intensivity of the effects, is necessary. The different variants of the joint and the space structure element modelling are gested. It allows to consider the complex modes of the joint bending-torsional oscillations of such structures as bridges, towers, high-rise buildings. The peculiarities of the modelling and testing of some problems of the objects aerodynamics and the interaction of the frameworks constructions with shock and movable loads are considered. In this paper the examples of the complex-composite structure dynamic analysis are shown. It is achieved by means of some special methods of the input of the real inducements and loads of the exploitated analog-object into the computing model. The suggested models found a wide use both at the design of new structures and the dynamic monitoring of the exploitated structures.
Pre-stressed structural elements are widely used in large-span structures. As a rule, they have higher stiffness characteristics. Pre-stressed rods can be applied as girders of different purpose, and as their separate parts, e.g. rods of trusses and frames. Among numerous ways of prestressing the compression of girders, trusses, and frames by tightenings from high-strength materials is under common application.
Analysis System for Bridge Test (Chinese name abbr.: QLJC) is an application software specially designed for bridge test to analyze the static and dynamic character of bridge structures, calculate efficiency ratio of load test, pick up the results of observation points and so on. In this paper, research content, system design, calculation theory, characteristics and practical application of QLJC is introduced in detail.
In this paper we present a computer aided method supporting co-operation between different project partners, such as architects and engineers, on the basis of strictly three-dimensional models. The center of our software architecture is a product model, described by the Industry Foundation Classes (IFC) of the International Alliance for Interoperability (IAI). From this a geometrical model is extracted and automatically transferred to a computational model serving as a basis for various simulation tasks. In this paper the focus is set on the advantage of the fully three-dimensional structural analysis performed by p-version of the finite element analysis. Other simulation methods are discussed in a separate contribution of this Volume (Treeck 2004). The validity of this approach will be shown in a complex example.
We consider the standardization problem (SP) which can be formulated as follows. It is known demand bi in each type i in {1, 2, ..., n} of items. Production of yi items of the ith type brings a profit fi (yi), where fi is a nondecreasing concave function for each i in {1, 2, ..., n}.It is necessary to satisfy the demand and to maximize the total profit provided that there exist >standardization possibilities< . These possibilities means that some types of items can be replaced by some another types. We introduce generalized standardization problem (GSP) in which titems demand is given as the set of admissible demand vectors. We show that GSP and SP are special cases of the resource allocation problem over a network polymatroid. Ibasing on this observation we propose a polynomial time solution algorithm for GSP and SP.
Eine der wichtigsten Aufgaben und Herausforderungen der Bauinformatik ist gegenwärtig die Realisierung des durchgängigen, fachübergreifenden Datenflusses im Planungsprozeß eines Bauvorhabens. Im Hinblick auf die internationale Wettbewerbsfähigkeit der deutschen Bauwirtschaft ist es unumgänglich, vorhandene Effizienzpotentiale in der Bauplanung auszuschöpfen, welche durch eine qualitative Verbesserung der Planung sowie durch eine Verringerung der Bearbeitungszeit aller beteiligten Fachplanern erreicht werden können. Nach dem gegenwärtigen Stand der Technik werden die Informationsobjekte standardisiert, damit sie durchgängig nutzbar sind. Diese werden in einem allgemeingültigen Format den speziellen Programmen der Fachplaner zur Verfügung gestellt. In dieser Arbeit wird der Ansatz verfolgt, eine Integration durch die Standardisierung der Kommunikation zwischen den Informationsobjekten und ihren Anwendungsprogrammen zu erreichen. Dabei kann auf die Standardisierung der zu übertragenden Objekte verzichtet werden. Ziel der Ausarbeitung ist die Definition von implementationstechnischen Regeln, die alle auszutauschenden Objekte sowie die Anwendungen, die solche Objekte aufnehmen wollen, erfüllen müssen. Die Bearbeitung der Objekte soll in den gewohnten Anwendungen in unveränderter Weise erfolgen.
The frame of this paper is the development of methods and procedures for the description of the motion of an arbitrary shaped foundation. Since the infinite half-space cannot be properly described by a model of finite dimensions without violating the radiation condition, the basic problems are infinite dimensions of the half-space as well as its non-homogeneous nature. Consequently, an approach has been investigated to solve this problem indirectly by developing Green's function in which the non-homogeneity and the infiniteness of the half-space has been included. When the Green's function is known, the next step will be the evaluation of contact stresses acting between the foundation and the surface of the half-space through an integral equation. The equation should be solved in the area of the foundation using Green's function as the kernel. The derivation of three-dimensional Green's function for the homogeneous half-space (Kobayashi and Sasaki 1991) has been made using the potential method. Partial differential equations occurring in the problem have been made ordinary ones through the Hankel integral transform. The general idea for obtaining the three-dimensional Green's function for the layered half-space is similar. But in that case some additional phenomena may occur. One of them is the possibility of the appearance of Stonely surface waves propagating along the contact surfaces of layers. Their contribution to the final result is in most cases important enough that they should not be neglected. The main advantage of results presented in comparing to other obtained with numerical methods is their accuracy especially in the case of thin layers because all essential steps of Green's function evaluation except of the contour integration along the branch cut have been made analytically. On the other hand the disadvantage of this method is that the mathematical effort for obtaining the Green's function is increasing drastically with the increase of the number of layers. Future work will therefore be directed in simplifying of the above described process
SLang - the Structural Language : Solving Nonlinear and Stochastic Problems in Structural Mechanics
(1997)
Recent developments in structural mechanics indicate an increasing need of numerical methods to deal with stochasticity. This process started with the modeling of loading uncertainties. More recently, also system uncertainty, such as physical or geometrical imperfections are modeled in probabilistic terms. Clearly, this task requires close connenction of structural modeling with probabilistic modeling. Nonlinear effects are essential for a realistic description of the structural behavior. Since modern structural analysis relies quite heavily on the Finite Element Method, it seems to be quite reasonable to base stochastic structural analysis on this method. Commercially available software packages can cover deterministic structural analysis in a very wide range. However, the applicability of these packages to stochastic problems is rather limited. On the other hand, there is a number of highly specialized programs for probabilistic or reliability problems which can be used only in connection with rather simplistic structural models. In principle, there is the possibility to combine both kinds of software in order to achieve the goal. The major difficulty which then arises in practical computation is to define the most suitable way of transferring data between the programs. In order to circumvent these problems, the software package SLang (Structural Language) has been developed. SLang is a command interpreter which acts on a set of relatively complex commands. Each command takes input from and gives output to simple data structures (data objects), such as vectors and matrices. All commands communicate via these data objects which are stored in memory or on disk. The paper will show applications to structural engineering problems, in particular failure analysis of frames and shell structures with random loads and random imperfections. Both geometrical and physical nonlinearities are taken into account.
Die Sicherheit von Tragwerken hängt von der zuverlässigen Modellierung sämtlicher Tragwerksparameter ab. Üblicherweise werden diese Parameter als deterministische oder stochastische Größen beschrieben. Stochastische Größen sind Zufallsgrößen, die unscharfe Informationen über Tragwerksparameter mit Hilfe von Dichtefunktionen erfassen. Nicht alle unscharfen Tragwerksparameter lassen sich als Zufallsgrößen darstellen. Sie können jedoch als Fuzzy-Größen modelliert werden. Fuzzy-Größen beschreiben unscharfe Tragwerksparameter als unscharfe Menge mit Bewertungsfunktion (Zugehörigkeitsfunktion). Die Fuzzy-Modellierung im Bauingenieurwesen umfaßt die Fuzzifizierung, die Fuzzy-Analyse, die Defuzzifizierung und die Sicherheitsbeurteilung. Sie erlaubt es, Tragwerke mit nicht-stochastischen unscharfen Eingangsinformationen zu untersuchen. Nicht-stochastische Eingangsinformationen treten sowohl bei bestehenden als auch bei neuen Tragwerken auf. Die unscharfen Ergebnisse der Fuzzy-Modellierung gestatten es, das Systemverhalten zutreffender zu beurteilen; sie sind die Ausgangspunkte für eine neue Sicherheitsbeurteilung auf der Grundlage der Möglichkeitstheorie. Bei der Fuzzy-Analyse ist die alpha-Diskretisierung vorteilhaft einsetzbar. Bei fehlender Monotonie der deterministischen Berechnungen und unter Berücksichtigung der Nichtlinearität wird die Fuzzy-Analyse mit Optimierungsalgorithmen durchgeführt. Zwei Beispiele werden diskutiert: die Lösung eines transzendenten Eigenwertproblems und eines linearen Gleichungssystems. Die Systemantworten der Fuzzy-Analyse werden der Sicherheitsbeurteilung zugrunde gelegt. Für ausgewählte physikalische Größen werden Versagensfunktionen definiert. Diese bewerten die Möglichkeit des Versagens. Mit Hilfe von Min-max-Operationen der Fuzzy-Set-Theorie erhält man aus Versagensfunktion und Fuzzy-Antwort die Versagensmöglichkeit bzw. die Überlebensmöglichkeit. Die ermittelte Versagensmöglichkeit repräsentiert die subjektive Beurteilung der Möglichkeit, daß das Ereignis &qout;Versagen&qout; eintritt. Beispiele zeigen die Unterschiede zwischen der Sicherheitsbeurteilung mittels Fuzzy-Modells und mittels deterministischen Modells.
This work was partially supported by DAAD, Fundamental Researches Foundation of Belarus and International Soros Science Education Program We consider a vector discrete optimization problem on a system of non- empty subsets (trajectories) of a finite set. The vector criterion of the pro- blem consists partial criterias of the kinds MINSUM, MINMAX and MIN- MIN. The stability of eficient (Pareto optimal, Slater optimal and Smale op- timal) trajectories to perturbations of vector criterion parameters has been investigated. Suficient and necessary conditions of eficient trajectories local stability have been obtained. Lower evaluations of eficient trajectories sta- bility radii, and formulas in several cases, have been found for the case when l(inf) -norm is defined in the space of vector criterion parameters.