Die Verwendung von virtuellen 3D-Modellen bei der SiGeKo-Planung auf Baustellen

In vorliegender Arbeit wird beispielhaft die Möglichkeit der Integration der Arbeitssicherheit in das 4D-Modell (virtueller Ablaufplan des 3D-Modells) eines Bauwerkes analysiert und visualisiert. Dabei wurde die Sicherung eines Treppenaufgangs als Arbeitsposition des SiGeKo-Planes in den virtuellen Ablaufplan des 3D-Modells übernommen. Zur Erleichterung des Visualisierungsaufwandes werden ebenso Technologien untersucht, die den Zugriff auf 3D-Bibliotheken ermöglichen, die entsprechende Werkzeuge des Arbeitsschutzes für den SiGeKo-Planer vorhalten

Determination of process durations on virtual construction sites

The paper analyses the application of 3D gaming technologies in the simulation of processes associated with human resources and machinery on construction sites in order to determine process costs. It addresses the problem of detailing in process simulation. The authors outline special boundary conditions for the simulation of cost-relevant resource processes on virtual construction sites. The approach considers different needs for detailing in process simulation during the planning and building phase. For simulation of process costs on a construction site (contractors view) the level of detail has to be set to high. A prototype for determination of process durations (and hereby process costs) developed at the Bauhaus University Weimar is presented as a result of ongoing researches on detailing in process simulation. It shows the method of process cost determination on a high level of detail (game between excavator and truck) through interaction with the virtual environment of the site

Job Description by Interactive Production Modeling on Virtual Construction Sites

Heutige Methoden zur Soll-Spezifikation von Bauleistungen (Kostenermittlung und zeitliche Ablaufplanung) gehen von einer abstrahierten und vereinfachten Betrachtung der Zusammenhänge bei Bauprojekten aus. Leistungsverzeichnisse, Kostenermittlungen und Bauzeitpläne orientieren sich nur indirekt an der Geometrie des Bauwerks und der Baustelle. Die dabei verwendeten Medien wie Papier, 2D-Dateien, digitale Leistungsbeschreibungen oder 3D-Darstellungen lassen die Suche nach Informationen auf der Baustelle zu einem zeitaufwändigen und in Anbetracht existierender Medientechnologien ineffizienten Prozess werden. Interaktive virtuelle Umgebungen erlauben die Auflösung starrer Zusammenhänge durch interaktive Eingriffe des Anwenders und visualisieren komplexe bauproduktionstechnische Vorgänge. Das Konzept der visuellen interaktiven Simulation der Bauproduktion sieht vor, die Soll-Spezifikation anhand eines interaktiven 3D-Modells zu entwickeln, um räumliche Veränderungen und parallele Prozesse auf der virtuellen Baustelle im Rahmen der Entscheidungsfindung zum Bauablauf besser berücksichtigen zu können. Verlangt man einen hohen Grad an Interaktivität mit dem 3D-Modell, dann bieten sich Computerspieltechnologien sehr gut zu Verifikationszwecken an. Die visuelle interaktive Simulation der Bauproduktion ist damit als eine 3D-modellbasierte Methode der Prozessmodellierung zu verstehen, die Entscheidungen als Input benötigt und die Kostenermittlung sowie die zeitliche Ablaufplanung als Output liefert.Current methods for the description of construction works presume a high abstraction level to simplify the constraints between single processes of a process model. The determination of costs together with the specification of a time schedule form the primary components (to-be-built) of this description. Cost estimations, bills of quantities and bar charts are not directly connected to the geometry of the product nore of the construction site. The used media like paper, 2D-files or – in best case scenarios – 3D pictures lead us to a time-consuming information retrieval on the site. Considering modern media technologies these processes are inefficient and demand for alternative scenarios based on 3D-models. In this work a concept for interaction with a virtual construction site is presented. The user can interact with objects on the site in such a way that he initiates the execution of single process steps in the complex production model of the site. The approach to visual interactive simulation (VIS) leads to a to-be-built specification of construction works (determination of costs and 4D-model). Thus spatial changes and parallel processes can be considered when modeling the construction sequence on the virtuel site. If one requirement of the solution is a high level of interactivity between the user and the model then game development engines are a suitable tool for the verification of the approach. This work integrates tendering issues with cost estimation and 4D-modeling in order to develop an interactive method for the simulation of construction works. This simulation approach is based on the 3D-model of the site and requires human-based decisions as an input while delivering costs and a 4D-model on a high level of detail as an output

Determination of process durations on virtual construction sites

The paper analyses the application of 3D gaming technologies in the simulation of processes associated with human resources and machinery on construction sites in order to determine process costs. It addresses the problem of detailing in process simulation. The authors outline special boundary conditions for the simulation of cost-relevant resource processes on virtual construction sites. The approach considers different needs for detailing in process simulation during the planning and building phase. For simulation of process costs on a construction site (contractors view) the level of detail has to be set to high. A prototype for determination of process durations (and hereby process costs) developed at the Bauhaus University Weimar is presented as a result of ongoing researches on detailing in process simulation. It shows the method of process cost determination on a high level of detail (game between excavator and truck) through interaction with the virtual environment of the site

Fatigue condition monitoring of notched thermoplastic-based hybrid fiber metal laminates using electrical resistance measurement and digital image correlation

In this work, the monitorability of fatigue damage in notched thermoplastic-based hybrid fiber metal laminate, containing AA6082-T4 sheets and glass and carbon fiber-reinforced polyamide 6, is investigated using constant amplitude tests. Electrical resistance measurement and digital image correlation were combined to determine the initiation and evolution process of fatigue damage. Preliminary to the application of the electrical resistance measurement during fatigue load, basic investigations regarding necessary measurement accuracy and conditions, e.g. temperature and cross-section influence, were conducted to achieve reliable measurement results. Via digital image correlation fatigue crack growth was determined and correlated with the change in electrical resistance for two metal/fiber-reinforced polymer layer configurations (2/1 and 3/2) and notch geometries (drilling hole and double-edge notch). The results show that reliable detection of fatigue-related damage states is possible independent of aluminum sheet treatment (mechanically blasted or anodized surface), with earlier crack initiation and faster propagation for higher metal volume fraction (layer configuration 2/1). For the two investigated notch geometries an overall similar crack behavior was found. The electrical resistance values directly correlate to varieties of crack formation and growth, representing the aluminum sheet damage progress of the laminate well, and enabling the possibility of e.g. a limit value-based failure criterion. However, geometry and crack-related changes in electric current flow and thus current density must be taken into account for targeted monitoring of the laminate condition, as they cause significant changes in electrical resistance

Effective cost estimate and construction processes with 3D interactive technologies: Towards a virtual world of construction sites

The development of 3D technologies during the last decades in many different areas, leads us towards the complete 3D representation of planet earth on a high level of detail. On the lowest level we have geographical information systems (GIS) representing the outer layer of our planet as a 3D model. In the meantime these systems do not only give a geographical model but also present additional information like ownership, infrastructure and others that might be of interest for the construction business. In future these systems will serve as basis for virtual environments for planning and simulation of construction sites. In addition to this work is done on the integration of GIS systems with 3D city models in the area of urban planning and thus integration of different levels of detail. This article presents research work on the use of 3D models in construction on the next level of detail below the level of urban planning. The 3D city model is taken as basis for the 3D model of the construction site. In this virtual nD-world a contractor can organize and plan his resources, simulate different variants of construction processes and thus find out the most effective solution for the consideration of costs and time. On the basis of former researches the authors present a new approach for cost estimation and simulation using development technologies from game software

Neue Methoden für die bauteilorientierte Ausschreibung und Kalkulation unter Beachtung des Integrated Product Lifecycle Management von Bauwerken

Die Autoren stellen Grundlagen und Methoden zur Erstellung von Ausschreibungen und zur Durchführung der Kalkulation vor, die direkt mit dreidimensionalen Bauteilmodellen arbeiten. Dies trägt dazu bei, den gesamten Lebenszyklus eines Bauwerkes durchgängig über 3-D-Modelle beschreiben zu können. Im ersten Abschnitt werden grundlegende Überlegungen zum Einsatz von PLM/PDM-Technologien im Bauwesen angestellt. Im Anschluß daran wird die herkömmliche Ausschreibungsmethodik analysiert. Die Unterschiede zwischen einem konventionellen Leistungsverzeichnis und einem dreidimensionalen Bauteilkatalog (Objektdatenbank) hinsichtlich der Datenstruktur werden dargestellt. Hieraus abgeleitet werden Methoden und Prozesse bei der Erstellung einer 3-D-Leistungsbeschreibung entwickelt. Dazu wird eine geeignete Benutzer-Schnittstelle eines dreidimensionalen Bauteilkataloges vorgestellt. Schließlich werden praxisrelevante Probleme bei der Verwendung von Bauteilkatalogen erörtert. Ein wesentlicher Baustein ist die Kalkulation. Hier werden Kalkulationsmethoden basierend auf einem zweidimensionalen Leistungsverzeichnis und einem dreidimensionalen Bauteilkatalog miteinander verglichen. Ergänzt wird dies um Lösungen zur Anbindung von elektronischen Marktplätzen an den Bauteilkatalog zum Zweck der Preisbildung. Schließlich wird ein Ausblick gegeben, wie eine Synthese zwischen dreidimensionalem Bauteilkatalog und textlichen Standard-Leistungsbeschreibungen erreicht werden kann

Optimization of site layout planning with 3D technologies

Der Einsatz von CAD-Applikationen hat die Planungsarbeit im Bauwesen entscheidend verändert. In der Entwurfsplanung sind die Änderungen bereits deutlich erkennbar. Seit der Anwendung von dreidimensionalen Planungswerkzeugen kann der Bauherr das Bauwerk in seiner virtuellen Gesamtheit am Computer betrachten und bewerten. Dies bietet viele Vorteile. So ist der Planer gezwungen alle wesentlichen Details a priori exakt zu planen, wodurch viele Fehler vermieden werden können. Dies bietet insbesondere für Planungen in Baubetrieben, z.B. im Rahmen der Arbeitsvorbereitung, neue Einsatzmöglichkeiten.The article describes the use of 3D CAD for the planning of site layouts. The impetus is on crane simulation and movement in order to avoid crane collision during construction process

Crystal, Solution and In silico Structural Studies of Dihydrodipicolinate Synthase from the Common Grapevine

Dihydrodipicolinate synthase (DHDPS) catalyzes the rate limiting step in lysine biosynthesis in bacteria and plants. The structure of DHDPS has been determined from several bacterial species and shown in most cases to form a homotetramer or dimer of dimers. However, only one plant DHDPS structure has been determined to date from the wild tobacco species, Nicotiana sylvestris (Blickling et al. (1997) J. Mol. Biol. 274, 608–621). Whilst N. sylvestris DHDPS also forms a homotetramer, the plant enzyme adopts a ‘back-to-back’ dimer of dimers compared to the ‘head-to-head’ architecture observed for bacterial DHDPS tetramers. This raises the question of whether the alternative quaternary architecture observed for N. sylvestris DHDPS is common to all plant DHDPS enzymes. Here, we describe the structure of DHDPS from the grapevine plant, Vitis vinifera, and show using analytical ultracentrifugation, small-angle X-ray scattering and X-ray crystallography that V. vinifera DHDPS forms a ‘back-to-back’ homotetramer, consistent with N. sylvestris DHDPS. This study is the first to demonstrate using both crystal and solution state measurements that DHDPS from the grapevine plant adopts an alternative tetrameric architecture to the bacterial form, which is important for optimizing protein dynamics as suggested by molecular dynamics simulations reported in this study