TY - CHAP A1 - van Rooyen, G.C. A1 - Olivier, A. H. T1 - Notes on structural analysis in a distributed collaboratory N2 - The worldwide growth of communication networks and associated technologies provide the basic infrastructure for new ways of executing the engineering process. Collaboration amongst team members seperated in time and location is of particular importance. Two broad themes can be recognized in research pertaining to distributed collaboration. One theme focusses on the technical and technological aspects of distributed work, while the other emphasises human aspects thereof. The case of finite element structural analysis in a distributed collaboratory is examined in this paper. An approach is taken which has its roots in human aspects of the structural analysis task. Based on experience of how structural engineers currently approach and execute this task while utilising standard software designed for use on local workstations only, criteria are stated for a software architechture that could support collaborative structural analysis. Aspects of a pilot application and the results of qualitative performance measurements are discussed. KW - Ingenieurbau KW - Verteiltes System KW - Planungsprozess KW - Modellierung KW - Finite-Elemente-Methode Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-1451 ER - TY - JOUR A1 - Milbradt, Peter A1 - Schierbaum, Jochen A1 - Schwöppe, Axel T1 - Finite Cell-Elements of Higher Order N2 - The method of the finite elements is an adaptable numerical procedure for interpolation as well as for the numerical approximation of solutions of partial differential equations. The basis of these procedure is the formulation of suitable finite elements and element decompositions of the solution space. Classical finite elements are based on triangles or quadrangles in the two-dimensional space and tetrahedron or hexahedron in the threedimensional space. The use of arbitrary-dimensional convex and non-convex polyhedrons as the geometrical basis of finite elements increases the flexibility of generating finite element decompositions substantially and is sometimes the only way to get a clear decomposition... KW - Finite-Elemente-Methode KW - Physikalisches Verfahren Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2524 ER - TY - JOUR A1 - Kaklauskas, Gintaris A1 - Cervenka, Vladimir A1 - Cervenka, Jan T1 - Deflection Calculation of RC Beams: Finite Element Software versus Design Code Methods N2 - The paper investigates accuracy of deflection predictions made by the finite element package ATENA and design code methods ACI and EC2. Deflections have been calculated for a large number of experimental reinforced concrete beams reported by three investigators. Statistical parameters have been established for each of the technique at different load levels, separately for the beams with small and moderate reinforcement ratio. KW - Finite-Elemente-Methode KW - Physikalisches Verfahren KW - Balken Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2498 ER - TY - JOUR A1 - Pick, Tobias A1 - Heimsund, Bjoern-Ove A1 - Milbradt, Peter T1 - Development and Analysis of Sparse Matrix Concepts for Finite Element Approximation on general Cells N2 - In engineering and computing, the finite element approximation is one of the most well-known computational solution techniques. It is a great tool to find solutions for mechanic, fluid mechanic and ecological problems. Whoever works with the finite element method will need to solve a large system of linear equations. There are different ways to find a solution. One way is to use a matrix decomposition technique such as LU or QR. The other possibility is to use an iterative solution algorithm like Conjugate Gradients, Gauß-Seidel, Multigrid Methods, etc. This paper will focus on iterative solvers and the needed storage techniques... KW - Finite-Elemente-Methode KW - Physikalisches Verfahren KW - Bandmatrix Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2500 ER - TY - CHAP A1 - Baitsch, Matthias A1 - Hartmann, Dietrich T1 - Object Oriented Finite Element Analysis for Structural Optimization using p-Elements N2 - The optimization of continuous structures requires careful attention to discretization errors. Compared to ordinary low order formulation (h-elements) in conjunction with an adaptive mesh refinement in each optimization step, the use of high order finite elements (so called p-elements) has several advantages. However, compared to the h-method a higher order finite element analysis program poses higher demands from a software engineering point of view. In this article the basics of an object oriented higher order finite element system especially tailored to the use in structural optimization is presented. Besides the design of the system, aspects related to the employed implementation language Java are discussed. KW - Konzipieren KW - Bauwerk KW - Finite-Elemente-Methode Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-1089 ER - TY - JOUR A1 - Galffy, Mozes A1 - Wellmann Jelic, Andres A1 - Hartmann, Dietrich T1 - Lifetime-oriented modelling of vortex-induced across-wind vibrations on bridge tie rods N2 - The influence of vortex-induces vibrations on vertical tie rods has been proved as a determinant load factor in the lifetime-oriented dimensioning of arched steel bridges. Particularly, the welded connection plates between the suspenders and the arches often exhibit cracks induced primarily rods. In this context, the synchronization of the vortex-shedding to the rod motion in a critical wind velocity range, the so-called lock-in effect, is of essential interest. KW - Finite-Elemente-Methode KW - Physikalisches Verfahren KW - Brückenbau KW - Schwingung Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2536 ER - TY - THES A1 - Lehmkuhl, Hansjörg T1 - Zur praktischen Anwendung numerischer Analysemethoden für Stabilitätsprobleme T1 - The application of numerical methods to stability problems in practice N2 - In der täglichen Ingenieurpraxis werden in zunehmenden Maße numerische Analysen im Rahmen der Finite-Elemente-Methode auch zur Untersuchung stabilitätsgefährdeter Strukturen eingesetzt. Für die aktuelle Praxis, insbesondere im konstruktiven Stahlbau, ist jedoch festzustellen, dass zwischen der fortgeschrittenen Theorie und dem Niveau der praktischen Anwendung numerischer Stabilitätsanalysen eine große Kluft besteht. Aus praktischer Sicht erscheint es unumgänglich, die weiter wachsende Diskrepanz zwischen den umfangreichen theoretischen Möglichkeiten und der gegenwärtigen Praxis abzubauen. Damit steht der praktisch tätige Ingenieur vor der Aufgabe, sein Wissen auf dem Gebiet numerischer Stabilitätsanalysen zu vertiefen und bereits vorhandene FE-Programme um Berechnungsalgorithmen für umfassende numerische Stabilitätsanalysen zu erweitern. Dafür werden in der Arbeit die Grundlagen einer FEM- orientierten modernen Stabilitätstheorie einheitlich und aus Sicht einer praktischen Anwendung aufbereitet. Die Darstellung von realisierten programmtechnischen Umsetzungen für erweiterte Analysenmethoden wie Nachbeulanalysen, Pfadwechsel und Approximationen imperfekter Pfade ermöglicht eine Erweiterung des Methodenvorrates. Die innerhalb der Arbeit untersuchten Beispiele zeigen, dass durch die Anwendung der behandelten Verfahren das Tragverhalten einer stabilitätsgefährdeten Struktur wesentlich besser eingeschätzt werden kann als bei Beschränkung auf die herkömmlichen Analysemethoden. N2 - The daily engineering practice is characterized by an increasing use of numerical analyses also for structures influenced by stability problems. However it must be noticed that in practice, especially in steel construction, exists a large gap between the advanced stability theory and the level of practical applications of numerical stability analyses. From a practical point of view it seems be absolutely necessary to break up the continual growing discrepancy between comprehensive theoretical possibilities and current practice. Therefore practical engineers have to deepen their knowledge on the field of numerical stability analyses and have to expand existing finite element programs with special algorithms. For this purpose basics of a finite element orientated modern stability theory are presented from the view of practical application. Furthermore steps are shown for programming special methods like post-buckling analyses, path switching and approximations for load-deformation pathes including imperfections. The importance of the additional methods for a better understanding of the structures stability behaviour clearly comes out by the presentation of different examples of practical relevance. KW - Nichtlineare Stabilitätstheorie KW - Finite-Elemente-Methode KW - Stabilität KW - Stahlbau KW - Imperfektion KW - Nachbeulverhalten KW - Schale KW - Non-linear buckling KW - Finite Element Method KW - stability theory KW - post-buckling analysis KW - koiter approximation Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20051013-7102 ER - TY - JOUR A1 - Melnikov, B. E. A1 - Semenov, Artem T1 - Application of Multimodel Method of Elasto-Plastic Analysis for the Multilevel Computation of Structures N2 - Creation of hierarchical sequence of the plastic and viscoplastic models according to different levels of structure approximations is considered. Developed strategy of multimodel analysis, which consists of creation of the inelastic models library, determination of selection criteria system and caring out of multivariant sequential clarifying computations, is described. Application of the multimodel approach in numerical computations has demonstrated possibility of reliable prediction of stress-strain response under wide variety of combined nonproportional loading. KW - Finite-Elemente-Methode KW - Physikalisches Verfahren KW - Elastoplastizität Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2487 ER - TY - JOUR A1 - Kashiyama, Kazuo A1 - Hamada, Hidetaka A1 - Taniguchi, Takeo T1 - Large Scale Finite Element Simulation and Modeling Using GIS/CAD for Environmental Flows in Urban Area N2 - A large-scale computer modeling and simulation method is presented for environmental flows in urban area. Several GIS and CAD data were used for the preparation of shape model and an automatic mesh generation method based on Delaunay method was developed. Parallel finite element method based on domain decomposition method was employed for the numerical simulation of natural phenomena. The present method was applied to the simulation of flood flow and wind flow in urban area. The present method is shown to be a useful planning and design tool for the natural disasters and the change of environments. KW - Geoinformationssystem KW - Finite-Elemente-Methode KW - Stadtplanung Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2675 ER - TY - JOUR A1 - Ke, Chen A1 - Jian Ming, Lu T1 - Study of Analysis System for Bridge Test N2 - 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. KW - Finite-Elemente-Methode KW - Physikalisches Verfahren KW - Brückenbau KW - Straßenbrücke Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2547 ER - TY - JOUR A1 - Kaapke, Kai A1 - Milbradt, Peter T1 - Voronoi-based finite volume method for transport problems N2 - Transport problems, as, for instance, the transport of sediment in hydraulic engineering and the transport of harmful substances through porous media, play an important role in many fields of civil engineering. Other examples include the dissipation of heat or sound as well as the simulation of traffic with macroscopic models. The contribution explains the analysis of the applicability of Voronoi-based finite volume methods for the approximation of solutions of transport problems. A special concern is the discretisation of the transport equation. Current limitations of the method as well as ideas for stabilisation are explained with examples. KW - Finite-Elemente-Methode KW - Physikalisches Verfahren KW - Transport Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2558 ER - TY - JOUR A1 - Kwak, Hyo-Gyoung A1 - Kim, Jin-Kook T1 - Efficient Shoring System in RC Frame Structures N2 - In this paper, systematic analyses for the shoring systems installed to support the applied loads during construction are performed on the basis of the numerical approach. On the basis of a rigorous time-dependent analysis, structural behaviors of reinforced concrete (RC) frame structures according to the changes in design variables such as the types of shoring systems, shore stiffness and shore spacing are analyzed and discussed. The time-dependent deformations of concrete such as creep and shrinkage and construction sequences of frame structures are also taken into account to minimize the structural instability and to reach to an improved design of shoring system because these effects may increase the axial forces delivered to the shores. In advance, the influence of the column shortening effect, generally mentioned in a tall building structure, is analyzed. From many parametric studies, it has been finally concluded that the most effective shoring system in RC frame structures is 2S1R (two shores and one reshore) regardless of the changes in design variables. KW - Finite-Elemente-Methode KW - Physikalisches Verfahren KW - Skelettbau KW - Construction Sequence KW - Shoring System KW - Shore Stiffness KW - Shore Spacing Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2511 ER - TY - JOUR A1 - Lee, Kangkun A1 - Lee, Kijang T1 - Additional bending moment for shear-lag phenomenon in tube structures N2 - Framed-tube system with multiple internal tubes is analysed using an orthotropic box beam analogy approach in which each tube is individually modelled by a box beam that accounts for the flexural and shear deformations, as well as the shear-lag effects. A simple numerical modeling technique is proposed for estimating the shear-lag phenomenon in tube structures with multiple internal tubes. The proposed method idealizes the framed-tube structures with multiple internal tubes as equivalent multiple tubes, each composed of four equivalent orthotropic plate panels. The numerical analysis is based on the minimum potential energy principle in conjunction with the variational approach. The shear-lag phenomenon of such structures is studied taking into account the additional bending moments in the tubes. A detailed work is carried out through the numerical analysis of the additional bending moment. The moment factor is further introduced to identify the shear lag phenomenon along with the additional moment. KW - Finite-Elemente-Methode KW - Physikalisches Verfahren KW - Hochhaus Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2472 ER - TY - JOUR A1 - Mironov, Vadim A1 - Pahl, Peter Jan T1 - A Prismatic Finite Element for Accurate Arch Dam Analysis N2 - The displacements and stresses in arch dams and their abutments are frequently determined with 20-node brick elements. The elements are distorted near the contact plane between the wall and the abutment. A cantilever beam testbed has been developed to investigate the consequences of this distortion. It is shown that the deterioration of the accuracy in the computed stresses is significant. A compatible 18-node wedge element with linear stress variation is developed as an alternative to the brick element. The shape of this element type is readily adapted to the shape of the contact plane. It is shown that the accuracy of the computed stresses in the vicinity of the contact plane is improved significantly by the use of wedge elements. KW - Finite-Elemente-Methode KW - Physikalisches Verfahren KW - Dammbau Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2467 ER - TY - JOUR A1 - Noh, Jung-Hwi A1 - Park, Jong-Heon T1 - A Calculation of Initial Cable Force for Ko-Ha Grand Bridge N2 - The primary objective of initial shape analysis of a cable stayed bridge is to calculate initial installation cable tension forces and to evaluate fabrication camber of main span and pylon providing the final longitudinal profile of the bridge at the end of construction. In addition, the initial cable forces depending on the alternation of the bridge’s shape can be obtained from the analysis, and will be used to provide construction safety during construction. In this research, we conducted numerical experiments for initial shape of Ko-ha bridge, which will be constructed in the near future, using three different typical methods such as continuous beam method, linear truss method, and IIMF (Introducing Initial Member Force) method KW - Finite-Elemente-Methode KW - Physikalisches Verfahren KW - Hängebrücke KW - cable stayed bridge KW - cable force KW - initial shape KW - initial equilibrium state Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2459 ER - TY - JOUR A1 - Most, Thomas A1 - Eckardt, Stefan T1 - Application of a hybrid parallelization technique to accelerate the numerical simulation of nonlinear mechanical problems N2 - This paper presents the combination of two different parallelization environments, OpenMP and MPI, in one numerical simulation tool. The computation of the system matrices and vectors is parallelized with OpenMP and the solution of the system of equations is done with the MPIbased solver MUMPS. The efficiency of both algorithms is shown on several linear and nonlinear examples using the Finite Element Method and a meshless discretization technique. KW - Framework KW - API KW - Parallelverarbeitung KW - Finite-Elemente-Methode Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2599 ER -