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 Design of adhesively bonded timber-concrete composites : bondline properties(2023) Grönquist, Philippe; Müller, Katharina; Mönch, Simon; Frangi, AndreaItem Open Access Rationale of detailing provisions in MC 78 and identification of missing items(1986) Eligehausen, RolfThe quality of a structure depends significantly on the quality of the detailing of the reinforcement. If failures occur, they are often caused by poor detailing, but rarely by incorrect structural analysis. Therefore the MC 78 pays close attention to this subject. The corresponding provisions are given in Section 17 and 18 of the Model Code.Item Open Access Post-processing tools for nonlinear fe analysis of concrete structures(1990) Cervenka, Vladimir; Pukl, Radomir; Eligehausen, RolfFinite clement analysis of the cracking process in concrete structures brings new requirements for the post-processing environment. Crack direction and location are important for identification of the failure mode. The problem have been solved in the finite element program SBETA which was developed by the authors for simulation of the failure processes in reinforced concrete structures. The post-processing system creates the graphical images of crack patterns. Graphical sequences for simulation can be generated.Item Open Access Numerical analysis of headed studs embedded in large plain concrete blocks(1990) Ozbolt, Josko; Eligehausen, RolfAnchoring elements such as headed studs, expansion, grouted or undercut anchors are used for local transfer of loads into concrete members. Parameter study of the behavior of headed stud anchors with embedment depth h v= 130 mm and failing by pulling out a concrete cone, is performed through numerical analysis. Compression and tension strength, fracture energy and the head diameter are varied. Numerical analysis is performed using nonlocal microplane model and axisymmetric finite elements. Results of the analysis are compared with experimental results.Item Open Access Rotation capacity of prestressed concrete members(1992) Eligehausen, Rolf; Li, LongfeiA numerical investigation on the behaviour of plastic hinges in prestressed concrete structures is presented. The object of the study is to determine the rotation capacity of prestressed concrete members which is needed to predict the amount of moment redistribution in hyperstatic prestressed concrete structures. A numerical model has been developed for the analysis of plastic hinges in prestressed concrete structures. It is based on a simply supported beam which simulates the region between two points of zero moment in a continuous beam. A discrete crack model has been applied in the numerical analysis. Realistic constitutive laws of steel, concrete and bond of reinforcing and prestressing steel have been assumed, respectively. The developed model enables an accurate analysis of the load deformation response of a statically determinate prestressed concrete beam with bonded or unbonded tendons under monotonic loading throughout all behaviour states up to failure . The parameters influencing the rotation capacity of prestressed concrete beams were studied by means of the numerical model.Item Open Access Fastening elements in concrete structures - numerical simulations(1993) Ozbolt, Josko; Eligehausen, RolfAnchoring elements such as headed and expansion studs and grouted or undercut anchors, are often used for local transfer of loads into concrete members. In order to better understand the failure mechanism, a large number of experiments have been carried out in the past. However, due to the complicated three-dimensional load transfer a very few or no numerical studies have been performed for a number of different fastening situations i.e. influence of the embedment depth, crack-width inftuence (fastening in cracked concrete), influence of the edge distance etc. Therefore, in the present study some results of the axisymmetric and three-dimensional numerical analysis of the headed studs embedded in plane concrete block are presented. Influence of different geometrical and material parameters have been studied employing finite element method and nonlocal microplane model. Comparison between experimental and numerical results indicate reasonable good agreement. Generally it has been observed that the failure mechanism is governed by fracture energy rather than by tensile strength of concrete. As a consequence, the size effect is strong and close to linear elastic fracture mechanics.