Baris Wenzel

Zusammenfassung

A range of established methods are currently available for the production of digital models to document, survey, or further develop buildings. Equipment and other technologies have been adopted from other disciplines, such as geodesy, and further developed specifically for the construction industry. These methods, therefore, have a very specific purpose and quickly reach their limits when they leave this primary area of application. As part of a research project “Last Witnesses – Physical Models in Civil Engineering” funded by the German Research Foundation (DFG SPP 2255), an attempt was made to transfer known methods of retro-digitisation from architecture to smaller-scale objects to create digital representations. These small-scaled objects are so-called physical models (Messmodelle), a particular type of model mainly used in civil engineering in the past to test load-bearing structures. The models were mainly used in the 20th century to calculate the behaviour of complex structures; however, both the model building and the mathematical calculations were very time consuming and prone to errors. From the 1960s and 1970s onwards they were replaced by the first powerful computers in the construction industry. This contribution will discuss the special characteristics of these physical models and why they were replaced by computers. We describe the applicability of the different non-destructive methods of retrodigitisation and analyse the advantages and disadvantages of the structured light 3D scan, the 3D laser scan, and photogrammetry. In a further step, the potential of the produced digital twins in different contexts, such as restoration, engineering, or architectural history, will be demonstrated.

Zusammenfassung

Abstract Das Forschungsprojekt „‚Die letzten Zeugen‘ Messmodelle im Ingenieurbauwesen – wissenschaftliche Bedeutung und Erhaltung“ wurde im Rahmen des Schwerpunktprogramms 2255 „Kulturerbe Konstruktion“ der Deutschen Forschungsgemeinschaft (DFG) gefördert und besteht aus drei Teilprojekten verteilt auf die Universität Innsbruck, die Hochschule Karlsruhe und die Technische Universität München. Das Projekt hat es sich zur Aufgabe gemacht, die letzten noch erhaltenen Messmodelle im deutschsprachigen Raum ausfindig zu machen, zu dokumentieren, bautechnikhistorisch einzuordnen, zu digitalisieren und restauratorisch zu bewerten. Dieser Beitrag soll einen Überblick über die Ausgangslage, die Vorgehensweisen, die Schwierigkeiten und erzielten Ergebnisse und Erkenntnisse aus dem Projekt geben. , Translation abstract Measurement models in civil engineering. A review The research project “‘Last Witnesses’ Measurement Models in Civil Engineering – Scientific Significance and Preservation” was funded as part of the priority program 2255 “Construction as Cultural Heritage” of the German Research Foundation (DFG) and consists of three sub‐projects divided between the University of Innsbruck, the Karlsruhe University of Applied Sciences and the Technical University of Munich. The project aimed to locate the last surviving measurement models in German‐speaking countries, document them, classify them in terms of construction history, digitise them and evaluate their state of conservation. This report is intended to provide an overview of the initial situation, the approaches, the difficulties and the results and findings achieved in the project.

Zusammenfassung

Abstract Im Rahmen des Forschungsprojekts „Last Witnesses – Messmodelle im Ingenieurbauwesen – wissenschaftliche Bedeutung und Erhaltung“, gefördert durch die DFG im Schwerpunktprogramm 2255 „Kulturerbe Konstruktion“, wurden die wenigen überlieferten Messmodelle aus der Epoche der Modellstatik untersucht und dokumentiert. Dieser Bericht gibt Einblick in die für das Münchner Olympiadach gebauten physischen Modelle und ihre Verwendung im Planungsprozess. Dabei werden die Grenzen der Methode der Modellstatik bei großen Seilnetzkonstruktionen deutlich und wie dies die Digitalisierung in Architektur und Bauwesen beförderte. , Translation abstract The cable net models for the Olympic roof landscape in Munich. Last witnesses of model analysis As part of the research project “Last Witnesses measurement models in civil engineering – scientific significance and preservation”, funded by the DFG in the priority programme 2255 ”Construction as Cultural Heritage“, the few surviving measurement models from the era of model analysis were examined and documented. This report provides insight into the physical models built for the Munich Olympic roof and their use in the planning process. The limitations of the model analysis method for large cable net constructions become clear and how this promoted digitalization in architecture and structural engineering.

Zusammenfassung

Since ancient times, physical processes have been explored with models to understand the laws of nature. In the late 15th century Leonardo da Vinci researched the behaviour of bending of elastic beams of various spans using physical models. Later, in the 20th century, physical models were indispensable for civil engineers and architects to check the load-bearing capacity of unconventional and innovative structures. Even today, physical models are used in different engineering disciplines, for example, to test the behaviour of long-span bridges in wind tunnels. This paper attempts to give an overview of important testing facilities which achieved technological progress in the field of bridge engineering. The models built and the tests performed in these facilities will be used as examples and will answer the question of the critical role these models played in the planning and construction process. The authors are collecting information and are analysing these physical measurement models in the current research project, “Last Witnesses”, funded by the German Research Foundation (DFG) to replicate some of them as digital twins. The results will be available to the public in an openly accessible database

Zusammenfassung

The New Little Belt Bridge, designed by the consulting engineers Christian Ostenfeld and Wriborg Jønson, was to be Denmark's first suspension bridge. The construction of this Danish piece of engineering history took place between 1965 and 1970 and could only succeed with the help of tests on physical models. Most of the physical models have disappeared, only the three-dimensional dynamic model of the bridge has survived. This paper looks at the question which role the surviving and other models played in the planning process. The model still existing is a store of knowledge of engineering practice and shall be recorded and evaluated as one of the last witnesses of model statics. Therefore, the authors will create a digital twin of the model to examine aspects like boundary conditions, structural parameters of all bridge components and the well-documented research results.

Zusammenfassung

The so-called IL pavilion in Stuttgart, constructed by Frei Otto and the Institute for Lightweight Structures (IL) served itself as an experimental building for testing the execution of a new type of cable net construction. At this 1:1 mock-up various manufacturing techniques and measuring methods were tested, additionally to model tests on physical models. These models were necessary, because at that time no adequate calculation methods were available to design the complex geometries of such wide-span cable net constructions. In this paper, the authors clarify the way the model was produced, the development of the measurement methods and the impact of model testing for the execution of the innovative construction of the German pavilion for the World's Fair in Montréal in 1967. The physical model, which is one of the few surviving measurement models from this period, was digitally rebuilt with state of the arts methods in the context of the DFG research project “last witnesses”. The data extracted from the physical model was compared with a model generated from the original cut stencils. Overall, the numbers match fairly well, nevertheless there are some outliers due to the changed numbers of elements, which have a deviation of more than 40\%. The data extracted from the digital twin will further be used to evaluate changed boundary conditions, increased snow loads or wind effects for the building itself and to record the actual state of the model for future preservation measures.