Discussion of "Influence of effective parameters of non-orthogonal smeared crack approach in seismic response of concrete arch dams"

2004 ◽  
Vol 31 (4) ◽  
pp. 712-713
Author(s):  
Harald Kreuzer
Keyword(s):  
Seismic Response ◽  
Effective Parameters ◽  
Arch Dams ◽  
Smeared Crack Approach ◽  
Smeared Crack

Influence of effective parameters of non-orthogonal smeared crack approach in seismic response of concrete arch dams

2003 ◽  
Vol 30 (5) ◽  
pp. 890-901 ◽  
Author(s):  
Radin Espandar ◽  
Vahid Lotfi ◽  
Ghani Razaqpur
Keyword(s):  
Seismic Response ◽  
Nonlinear Dynamic Analysis ◽  
Arch Dam ◽  
Effective Parameters ◽  
Finite Element Program ◽  
Cracking Behavior ◽  
Arch Dams ◽  
Smeared Crack Approach ◽  
Element Program ◽  
Smeared Crack

A rigorous and relatively efficient algorithm based on the non-orthogonal smeared crack approach is coded in a special finite element program to study the seismic response of arch dams. The formulation is briefly presented. The 130 m high Shahid Rajaee arch dam in Iran subjected to the Friuli-Tolmezzo earthquake is selected to present a practical application of the technique. Under the same geometry and loading conditions, six nonlinear analyses with different parameters are performed, and the results are compared with each other and a linear case. The varied parameters include secant and elastic unloading–reloading options, threshold angle, and tensile strength of the material. It is concluded that the non-orthogonal smeared crack approach can redistribute the state of stresses and produces a more realistic profile of stresses in the dam. A drift in the crest displacements forms the prominent characteristics of the cracking behavior. The results also suggest that the dam can suffer significant cracking during a strong earthquake and still remain stable. Moreover, the influences of the mentioned parameters in the seismic response of the dam are comprehensively discussed.Key words: nonlinear dynamic analysis, concrete arch dam, smeared crack approach.

Non-linear seismic response of arch dams

1982 ◽  
Vol 10 (2) ◽  
pp. 267-281 ◽  
Author(s):  
Akira Niwa ◽  
Ray W. Clough
Keyword(s):  
Seismic Response ◽  
Arch Dams ◽  
Non Linear

scholarly journals Effects of Nonuniform Fiber Geometries on the Microstructural Fracture Behavior of Ceramic Matrix Composites

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Hye-gyu Kim ◽  
Wooseok Ji ◽  
Nam Choon Cho ◽  
Jong Kyoo Park
Keyword(s):  
Optimization Algorithm ◽  
Fracture Behavior ◽  
Ceramic Matrix Composite ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Shear Loading ◽  
Matrix Composites ◽  
Specific Loading ◽  
Smeared Crack Approach ◽  
Smeared Crack

Microstructural fracture behavior of a ceramic matrix composite (CMC) with nonuniformly distributed fibers is studied in the presentation. A comprehensive numerical analysis package to study the effect of nonuniform fiber dimensions and locations on the microstructural fracture behavior is developed. The package starts with an optimization algorithm for generating representative volume element (RVE) models that are statistically equivalent to experimental measurements. Experimentally measured statistical data are used as constraints while the optimization algorithm is running. Virtual springs are utilized between any adjacent fibers to nonuniformly distribute the coated fibers in the RVE model. The virtual spring with the optimization algorithm can efficiently generate multiple RVEs that are statistically identical to each other. Smeared crack approach (SCA) is implemented to consider the fracture behavior of the CMC material in a mesh-objective manner. The RVEs are subjected to tension as well as the shear loading conditions. SCA is capable of predicting different fracture patterns, uniquely defined by not only the fiber arrangement but also the specific loading type. In addition, global stress-strain curves show that the microstructural fracture behavior of the RVEs is highly dependent on the fiber distributions.

scholarly journals The Effect of Shear Sliding of Vertical Contraction Joints on Seismic Response of High Arch Dams with Fine Finite Element Model

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Shengshan Guo ◽  
Jianxin Liao ◽  
Hailong Huang ◽  
Hui Liang ◽  
Deyu Li ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Seismic Response ◽  
Element Model ◽  
Arch Dam ◽  
Slip Condition ◽  
Dead Load ◽  
High Arch Dam ◽  
Arch Dams ◽  
Contraction Joints

The contraction joints of arch dams with and without shear keys are simplified to be with no-slip condition and with relative sliding condition, respectively. Based on the Lagrange multiplier method, a contact model considering the manner of independent cantilever dead load type with no-slip condition and relative sliding condition is proposed to model the nonlinearities of vertical contraction joins, which is special to the nonlinear analysis of arch dams considering the manner of dead load type. Different from the conventional Gauss iterative method, the strategy of the alternating iterative solution of normal force and tangential force is employed. The parallelization based on overlapping domain decomposition method (ODDM) and explicit message passing using distributed memory parallel computers is employed to improve the computational efficiency. An existing high arch dam with fine finite element model is analyzed to investigate the effect of shear sliding of vertical joints on seismic response of the arch dam. The result shows that the values of maximum principal tensile stress under relative sliding condition are significantly greater than those under no-slip condition.

Evaluation of Formation of Plastic Hinge and Seismic Behavior of Steel Structures Due to Soil–Structure–Tunnel Interaction

2020 ◽  
Vol 14 (03) ◽  
pp. 2050014
Author(s):  
Arash Rostami ◽  
Abdolreza S. Moghadam ◽  
Mahmood Hosseini ◽  
Nima Asghari
Keyword(s):  
Seismic Response ◽  
Land Surface ◽  
Plastic Hinge ◽  
Free Field ◽  
Steel Structures ◽  
Underground Structures ◽  
Effective Parameters ◽  
Plastic Hinges ◽  
Underground Cavities ◽  
Real Earthquake

The seismic design of the structures is carried out by technical regulations and codes in free-field conditions (regardless of underground cavities). With the availability of tunnels and the complex interaction between the tunnel and the aboveground structures, which may be contemplated wrongly, it could be dangerous for over ground buildings and structures. Consequently, the examination of the underground tunnels and their impact on the land surface and adjacent buildings seismic response seems to be significant. The present research focuses on formation of the plastic hinges in steel structures due to underground cavities and the soil–tunnel–structure interaction of underground structures. First, an existing model was verified by finite element method and the results were compared with a sample specimen. Thus, several effective parameters were considered and studied such as soil type, multi-story structures (4, 8 and 12 stories) and dynamic load type. Then the models were evaluated under real earthquake records. As a result, the seismic response of the structures and plastic conditions of plastic hinge conditions were obtained. The results indicate that the underground cavities have affected the formation of plastic hinges in the structure. They increased the input energy to the structure and had an impact on the total behavior of the structures. Also, the high-rise structures were much more vulnerable to underground tunnels. Therefore, the structures which are located above the underground cavities should be retrofitted and rehabilitated.

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