Browsing by Author "Pukl, Radomir"

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Open Access
Computer models of concrete structures
(1991) Cervenka, Vladimir; Eligehausen, Rolf; Pukl, Radomir
The application of the nonlinear finite element analysis of concrete structures as a design tool is discussed. A computer program for structures in plane stress state is described and examples of its application in the research of fastening technique and in engineering practice are shown.
Open Access
Computer simulation of anchoring technique in reinforced concrete beams
(1990) Cervenka, Vladimir; Pukl, Radomir; Eligehausen, Rolf
The 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.
Open Access
Computer simulation of pullout tests of headed anchors in a state of plane-stress
(1992) Pukl, Radomir; Eligehausen, Rolf; Cervenka, Vladimir
Computer analyses of the pull-out tests of anchors embedded in concrete were performed for the Round Robin Analysis of the RILEM Committee on Fracture Mechanics of Concrete. The test specimens are concrete plates with steel anchors in the plane stress state. The geometry of the specimen is varied in order to study the size effect and the shape effect. The investigation is performed by means of the computer simulation of the tests. Only limited comparison with the real laboratory experiments is used to verify the results. The computer simulation is made by means of the program SBETA, which was developed by the authors and is based on the smeared crack approach and the nonlinear elasticity. Two crack models were used to analyze each specimen: rotated crack model and fixed crack model. In total 36 computer simulations were made. Each simulation provided the load-displacement diagram of the anchor and a sequence of crack patterns, deformed states and stress states. A size effect law in the exponential form was derived from the computer experiments.
Open Access
Computer simulation: splitting tests of concrete thick-walled rings
(1992) Pukl, Radomir; Schlottke, Bernd; Ozbolt, Josko; Eligehausen, Rolf
Two 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.
Open Access
Fracture analysis of concrete plane-stress pull-out tests
(1991) Cervenka, Vladimir; Pukl, Radomir; Eligehausen, Rolf
This paper reports on a parameter study which was performed for the Round Robin Analysis Of Anchor Bolts organized by RILEM Committee TC-90 FMA (Fracture Mechanics Applications). 18 plane-stress pull-out specimens were analyzed by the computer program SBETA which is based on the finite element method and takes into account nonlinear fracture mechanics. A simplified formula for the design of such anchors is derived.
Open Access
Post-processing tools for nonlinear fe analysis of concrete structures
(1990) Cervenka, Vladimir; Pukl, Radomir; Eligehausen, Rolf
Finite 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.
Open Access
Size effect of the concrete cone failure load of anchor bolts
(1992) Eligehausen, Rolf; Bouska, Petr; Cervenka, Vladimir; Pukl, Radomir
The concrete cone capacity of headed anchor bolts subjected to axial tension load was experimentally investigated using 35 concrete specimens of three different sizes. The dimensions of the test specimens were varied in proportion to the embedment depth h (h = 50, 150 and 450 mm). Material properties were measured on accompanying specimens. The measured failure loads are compared with other experimental and numerical investigations. According to the present results the failure loads increase in proportion to h 16, that means close to the prediction by linear fracture mechanics.