02 Fakultät Bau- und Umweltingenieurwissenschaften
Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/3
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Item Open Access Simulation of cracking and failure of concrete structures(1990) Cervenka, Vladimir; Eligehausen, RolfThe computer simulation of the cracking process in concrete structures is performed by means of the program system SBETA. The program is based on nonlinear hypo-elastic constitutive model, which covers all important, experimentally derived material properties, namely, cracking, nonlinear stress-strain law in compression, softenning in compression and tension, biaxial failure function, etc. The nonlinear fracture mechanics is included by means of the fictitious crack model and smeared crack approach. Two examples of computer simulation of concrete fracture are shown. In the first example, the failure mode of a pull-out test is presented. In the second example, the process of the crack development and shear failure of a reinforced concrete beam is simulated.Item Open Access Computer simulation of anchoring technique in reinforced concrete beams(1990) Cervenka, Vladimir; Pukl, Radomir; Eligehausen, RolfThe load transfer in reinforced concrete structures by means of anchoring elements is very common in modern concrete technology. Anchoring elements are often inserted in the bottom surface of a structure and the load is transfered by tensile action of the concrete. In case of shear failure, the anchores are located in the most exposed tensile zone of beams. The shear failure can be thus influenced by anchoring elements. This effect was analysed by means of the finite element program SBETA, which is based on the nonlinear-elastic constitutive model. The comparison with experiments for several loading configurations was made. In the second part a computer simulation of similar experiments was conducted.Item Open Access Computer simulation: splitting tests of concrete thick-walled rings(1992) Pukl, Radomir; Schlottke, Bernd; Ozbolt, Josko; Eligehausen, RolfTwo non-linear program systems are used for a computer simulation of splitting failure of thick-walled concrete rings under internal radial pressure. Results of the numerical analyses for plane stress models, axisymmetrical model and 3D model are compared with available experimental data and empirical formulas. It is shown, that the behavior observed in experiments can be simulated, using advanced material models, namely the non local microplane model and SBETA material model based on the crack hand theory. With increasing outer radius of the ring, a size effect can be observed.Item Open Access Finite element based design of timber structures(2023) Töpler, Janusch; Schweigler, Michael; Lemaître, Romain; Palma, Pedro; Schenk, Martin; Grönquist, Philippe; Tapia Camú, Cristóbal; Hochreiner, Georg; Kuhlmann, UlrikeItem Open Access Lateral torsional buckling of glulam beam-columns : axial compression and bending verification(2024) Töpler, Janusch; Kuhlmann, Ulrike; Schänzlin, JörgItem Open Access Managing uncertainties in LCA dataset selection(2019) Pfeuffer, Simon; Wehner, Daniel; Bouslama, RaedThe selection of LCA datasets requires an understanding of the available datasets in a database and awareness about the uncertainties associated with the dataset selection. Therefore, a graphical presentation technique is introduced to support the communication of information about available datasets and uncertainties.Item Open Access Frequency and safety of small radii on motorway-like roads in greater Stuttgart area - recommendations for future guidelines of motorways(2022) Holzwarth, JürgenThe German Guidelines for the Design of Motorways (RAA 2008) assume sufficient safety of a circular curvature if a vehicle does not slip of the road at a given design speed. Earlier researches indicated a higher accident-risk of small radii R < 1000m frequently used on motorwaylike road with a design speed of 100 kph given in German Guideline for Motorways RAA 2008. With regard to the “Vision Zero”, no fatal accidents, it was examined whether minimum radii should be increased to improve safety. For this purpose, 174 km from the entire 200 km motorway-like road network in Greater Stuttgart Area were selected. The existing circular radii were evaluated according to their frequency and accident risk using databases of the State of Baden-Württemberg about road geometry and accidents including the accident cost rate for each 100 m section. Within the selected network 212 circular curves exist. All radii R ≤ 1000 m were examined for their accident cost rate. Radii with an accident cost rate above the average were classified as risky. The investigation showed that 33 % of all applied radii are below R < 1000m. Circular curves with R < 650m showed a significantly higher accident risk and should be excluded. Circular curves between R ≥ 650m and R < 900m showed a higher accident risk if the ratio of adjacent radii is considerably above R1/R2 ≥ 1.5. After a long straight line the minimum radius should be R ≥ 1000m. The study results in recommendations for the geometric design introduced by the follow-up of German Guidelines for Motorways.Item Open Access Design of adhesively bonded timber-concrete composites : bondline properties(2023) Grönquist, Philippe; Müller, Katharina; Mönch, Simon; Frangi, AndreaItem Open Access VEGAS - Versuchseinrichtung zur Grundwasser- und Altlastensanierung(1993) Kobus, Helmut; Teutsch, Georg; Koschitzky, Hans-Peter; Cirpka, OlafDie Versuchseinrichtung zur Grundwasser- und Altlastensanierung VEGAS, die derzeit an der Universität Stuttgart gebaut wird, wird aus einer Versuchshalle mit mehreren großmaßstäblichen Versuchsständen bestehen. Der Bau von VEGAS wird vom Bundesminister für Forschung und Technologie BMFT und vom Umweltministerium des Landes Baden-Württemberg im Rahmen des Projektes Wasser-Abfall-Boden PWAB finanziert und steht allen interessierten Forschungsnahmern aus der Bundesrepublik offen. VEGAS verfolgt im wesentlichen zwei Ziele: 1) Entwicklung und Optimierung von in-situ Sanierungsverfahren, 2) Prozeßforschung zum Schadstoffverhalten im Untergrund.Item Open Access Analytical and numerical investigations on imperfection-sensitive timber members subjected to combined bending and axial compression(2021) Töpler, Janusch; Kuhlmann, UlrikeThe verification of slender timber members at risk of lateral torsional buckling is one of the basic verifications in timber design. However, latest investigations have shown that the design formulas provided in Eurocode 5 for imperfection-sensitive members subjected to combined bending and compression tend to be conservative and more advanced verification methods are needed. Analytical and numerical models are presented that allow for the consideration of the geometrically and materially nonlinear behaviour as well as of the size effect of tensile strength ft,0 for Nx-My-Mz interaction. These models and calculation results increase the understanding of the main influencing parameters of the load-bearing capacity of imperfection-sensitive timber beams and columns and may be the basis of a revision of the current design formulas provided in EN 1995-1-1.