The Experts below are selected from a list of 45 Experts worldwide ranked by ideXlab platform

Jane Z Wang - One of the best experts on this subject based on the ideXlab platform.

Çavuşli M. - One of the best experts on this subject based on the ideXlab platform.

  • Assessing 3D seismic damage performance of a CFR dam considering various reservoir heights
    'Techno-Press', 2019
    Co-Authors: Karalar M., Çavuşli M.
    Abstract:

    Today, many important concrete face rockfill dams (CFRDs) have been built on the world, and some of these important structures are located on the strong seismic regions. In this reason, examination and monitoring of these water construction's seismic behaviour is very important for the safety and future of these dams. In this study, the nonlinear seismic behaviour of Ilisu CFR dam which was built in Turkey in 2017, is investigated for various reservoir water heights taking into account 1995 Kobe near-fault and far-fault ground motions. Three dimensional (3D) finite difference model of the dam is created using the FLAC3D software that is based on the finite difference method. The most suitable mesh range for the 3D model is chosen to achieve the realistic numerical results. Mohr-Coulomb nonlinear material model is used for the rockfill materials and foundation in the seismic analyses. Moreover, Drucker-Prager nonlinear material model is considered for the concrete slab to represent the nonlinearity of the concrete. The dam body, foundation and concrete slab constantly interact during the lifetime of the CFRDs. Therefore, the special interface elements are defined between the dam body-concrete slab and dam body-foundation due to represent the interaction Condition in the 3D model. Free Field Boundary Condition that was used rarely for the nonlinear seismic analyses, is considered for the lateral boundaries of the model. In addition, quiet artificial Boundary Condition that is special Boundary Condition for the rigid foundation in the earthquake analyses, is used for the bottom of the foundation. The hysteric damping coefficients are separately calculated for all of the materials. These special damping values is defined to the FLAC3D software using the special fish functions to capture the effects of the variation of the modulus and damping ratio with the dynamic shear-strain magnitude. Total 4 different reservoir water heights are taken into account in the seismic analyses. These water heights are empty reservoir, 50 m, 100 m and 130 m (full reservoir), respectively. In the nonlinear seismic analyses, near-fault and far-fault ground motions of 1995 Kobe earthquake are used. According to the numerical analyses, horizontal displacements, vertical displacements and principal stresses for 4 various reservoir water heights are evaluated in detail. Moreover, these results are compared for the near-fault and far-faults earthquakes. The nonlinear seismic analysis results indicate that as the reservoir height increases, the nonlinear seismic behaviour of the dam clearly changes. Each water height has different seismic effects on the earthquake behaviour of Ilisu CFR dam. In addition, it is obviously seen that near-fault earthquakes and far Field earthquakes create different nonlinear seismic damages on the nonlinear earthquake behaviour of the dam. © 2019 Techno-Press, Ltd

  • Evaluation of 3D Nonlinear Earthquake Behaviour of the Ilisu CFR Dam under Far-Fault Ground Motions
    'Hindawi Limited', 2019
    Co-Authors: Karalar M., Çavuşli M.
    Abstract:

    In the recent times, many huge concrete face rockfill dams (CFRDs) have been modelled and constructed in the world, and many of these dams are located on the strong earthquake zones. Examination of the seismic behaviour of a CFR dam built on the seismic zone is very important to assess the safety and future of the dam. For this reason, the nonlinear earthquake behaviour of these dams should be constantly observed taking into account the seismicity of the zone. In this study, three-dimensional (3D) seismic behaviour of the Ilisu dam built on the East Anatolian Fault (EAF) line is examined considering the effect of the important various far-fault earthquakes. The 3D finite difference model of the Ilisu dam is created using the FLAC3D software based on the finite difference method. The dam body, foundation, and concrete slab constantly interact during the lifetime of the CFRDs. Therefore, the special interface elements are defined between the dam body, concrete slab, and foundation to represent the interaction Condition. The Mohr-Coulomb nonlinear material model is used for the rockfill materials and foundation. Moreover, the concrete slab is modelled considering the Drucker-Prager nonlinear material model to represent the nonlinearity of the concrete. Very special seismic Boundary Conditions rarely used for CFR dams in the past are used in this work. These Boundary Conditions are free-Field and quiet Boundary Conditions. The free-Field Boundary Condition that is a very important Boundary Condition for the nonlinear seismic analyses is considered for the lateral boundaries of the 3D model. In addition, the quiet artificial Boundary Condition is used for the bottom of the foundation. While defining these Boundary Conditions, the special fish functions are created and defined to the software. Moreover, the hysteric damping coefficients are separately calculated for all of the materials. These special damping values are defined to the FLAC3D software using the special fish functions to capture the effects of the variation of the modulus and damping ratio with the dynamic shear-strain magnitude. In the numerical analyses, a total of 7 various strong far-fault earthquakes are used for the 3D nonlinear earthquake analyses, and 7 different numerical analyses are performed for the full-reservoir Condition of the Ilisu CFR dam. According to the seismic results, the principal stresses for the three critical nodal points on the dam body surface are examined and evaluated in detail. It is clearly understood that the nonlinear seismic behaviour of the Ilisu dam changes depending on the magnitudes and periods of the far-fault earthquakes. Each far-fault earthquake has different seismic effects on the nonlinear principal stress behaviour of the Ilisu CFR dam. © 2019 Memduh Karalar and Murat Çavuşli

Can Huang - One of the best experts on this subject based on the ideXlab platform.

  • a mixed characteristic Boundary Condition for simulating viscous incompressible fluid flows around a hydrofoil
    Journal of Marine Science and Technology, 2019
    Co-Authors: Dahai Zhang, Y X Shi, Can Huang
    Abstract:

    Smoothed particle hydrodynamics (SPH) is a meshfree method and has been widely used in the Field of fluid dynamics. However, there is still a lack of robust approach to implement the far-Field Boundary Condition in the simulation of free stream flow past the rigid body. To solve this problem, on the basis of Lastiwka et al.’s work, an improved non-reflecting Boundary Condition, called mixed characteristic Boundary Condition is proposed in this paper. The mixed characteristic Boundary Condition is tested by two-dimensional incompressible flows with a perturbation at the initial moment. The numerical results show that the mixed characteristic Boundary Condition can effectively suppress the reflection of waves on far-Field boundaries. Finally, flows past a hydrofoil are simulated within the framework of the kernel gradient free SPH in two kinds of non-reflecting Boundary Condition. The results indicate that the present Boundary Condition is more robust and suitable for SPH than the one adopted by Lastiwka et al.

Karalar M. - One of the best experts on this subject based on the ideXlab platform.

  • Assessing 3D seismic damage performance of a CFR dam considering various reservoir heights
    'Techno-Press', 2019
    Co-Authors: Karalar M., Çavuşli M.
    Abstract:

    Today, many important concrete face rockfill dams (CFRDs) have been built on the world, and some of these important structures are located on the strong seismic regions. In this reason, examination and monitoring of these water construction's seismic behaviour is very important for the safety and future of these dams. In this study, the nonlinear seismic behaviour of Ilisu CFR dam which was built in Turkey in 2017, is investigated for various reservoir water heights taking into account 1995 Kobe near-fault and far-fault ground motions. Three dimensional (3D) finite difference model of the dam is created using the FLAC3D software that is based on the finite difference method. The most suitable mesh range for the 3D model is chosen to achieve the realistic numerical results. Mohr-Coulomb nonlinear material model is used for the rockfill materials and foundation in the seismic analyses. Moreover, Drucker-Prager nonlinear material model is considered for the concrete slab to represent the nonlinearity of the concrete. The dam body, foundation and concrete slab constantly interact during the lifetime of the CFRDs. Therefore, the special interface elements are defined between the dam body-concrete slab and dam body-foundation due to represent the interaction Condition in the 3D model. Free Field Boundary Condition that was used rarely for the nonlinear seismic analyses, is considered for the lateral boundaries of the model. In addition, quiet artificial Boundary Condition that is special Boundary Condition for the rigid foundation in the earthquake analyses, is used for the bottom of the foundation. The hysteric damping coefficients are separately calculated for all of the materials. These special damping values is defined to the FLAC3D software using the special fish functions to capture the effects of the variation of the modulus and damping ratio with the dynamic shear-strain magnitude. Total 4 different reservoir water heights are taken into account in the seismic analyses. These water heights are empty reservoir, 50 m, 100 m and 130 m (full reservoir), respectively. In the nonlinear seismic analyses, near-fault and far-fault ground motions of 1995 Kobe earthquake are used. According to the numerical analyses, horizontal displacements, vertical displacements and principal stresses for 4 various reservoir water heights are evaluated in detail. Moreover, these results are compared for the near-fault and far-faults earthquakes. The nonlinear seismic analysis results indicate that as the reservoir height increases, the nonlinear seismic behaviour of the dam clearly changes. Each water height has different seismic effects on the earthquake behaviour of Ilisu CFR dam. In addition, it is obviously seen that near-fault earthquakes and far Field earthquakes create different nonlinear seismic damages on the nonlinear earthquake behaviour of the dam. © 2019 Techno-Press, Ltd

  • Evaluation of 3D Nonlinear Earthquake Behaviour of the Ilisu CFR Dam under Far-Fault Ground Motions
    'Hindawi Limited', 2019
    Co-Authors: Karalar M., Çavuşli M.
    Abstract:

    In the recent times, many huge concrete face rockfill dams (CFRDs) have been modelled and constructed in the world, and many of these dams are located on the strong earthquake zones. Examination of the seismic behaviour of a CFR dam built on the seismic zone is very important to assess the safety and future of the dam. For this reason, the nonlinear earthquake behaviour of these dams should be constantly observed taking into account the seismicity of the zone. In this study, three-dimensional (3D) seismic behaviour of the Ilisu dam built on the East Anatolian Fault (EAF) line is examined considering the effect of the important various far-fault earthquakes. The 3D finite difference model of the Ilisu dam is created using the FLAC3D software based on the finite difference method. The dam body, foundation, and concrete slab constantly interact during the lifetime of the CFRDs. Therefore, the special interface elements are defined between the dam body, concrete slab, and foundation to represent the interaction Condition. The Mohr-Coulomb nonlinear material model is used for the rockfill materials and foundation. Moreover, the concrete slab is modelled considering the Drucker-Prager nonlinear material model to represent the nonlinearity of the concrete. Very special seismic Boundary Conditions rarely used for CFR dams in the past are used in this work. These Boundary Conditions are free-Field and quiet Boundary Conditions. The free-Field Boundary Condition that is a very important Boundary Condition for the nonlinear seismic analyses is considered for the lateral boundaries of the 3D model. In addition, the quiet artificial Boundary Condition is used for the bottom of the foundation. While defining these Boundary Conditions, the special fish functions are created and defined to the software. Moreover, the hysteric damping coefficients are separately calculated for all of the materials. These special damping values are defined to the FLAC3D software using the special fish functions to capture the effects of the variation of the modulus and damping ratio with the dynamic shear-strain magnitude. In the numerical analyses, a total of 7 various strong far-fault earthquakes are used for the 3D nonlinear earthquake analyses, and 7 different numerical analyses are performed for the full-reservoir Condition of the Ilisu CFR dam. According to the seismic results, the principal stresses for the three critical nodal points on the dam body surface are examined and evaluated in detail. It is clearly understood that the nonlinear seismic behaviour of the Ilisu dam changes depending on the magnitudes and periods of the far-fault earthquakes. Each far-fault earthquake has different seismic effects on the nonlinear principal stress behaviour of the Ilisu CFR dam. © 2019 Memduh Karalar and Murat Çavuşli

Murat Çavuşli - One of the best experts on this subject based on the ideXlab platform.

  • Evaluation of 3D Nonlinear Earthquake Behaviour of the Ilısu CFR Dam under Far-Fault Ground Motions
    Hindawi Limited, 2019
    Co-Authors: Memduh Karalar, Murat Çavuşli
    Abstract:

    In the recent times, many huge concrete face rockfill dams (CFRDs) have been modelled and constructed in the world, and many of these dams are located on the strong earthquake zones. Examination of the seismic behaviour of a CFR dam built on the seismic zone is very important to assess the safety and future of the dam. For this reason, the nonlinear earthquake behaviour of these dams should be constantly observed taking into account the seismicity of the zone. In this study, three-dimensional (3D) seismic behaviour of the Ilısu dam built on the East Anatolian Fault (EAF) line is examined considering the effect of the important various far-fault earthquakes. The 3D finite difference model of the Ilısu dam is created using the FLAC3D software based on the finite difference method. The dam body, foundation, and concrete slab constantly interact during the lifetime of the CFRDs. Therefore, the special interface elements are defined between the dam body, concrete slab, and foundation to represent the interaction Condition. The Mohr–Coulomb nonlinear material model is used for the rockfill materials and foundation. Moreover, the concrete slab is modelled considering the Drucker–Prager nonlinear material model to represent the nonlinearity of the concrete. Very special seismic Boundary Conditions rarely used for CFR dams in the past are used in this work. These Boundary Conditions are free-Field and quiet Boundary Conditions. The free-Field Boundary Condition that is a very important Boundary Condition for the nonlinear seismic analyses is considered for the lateral boundaries of the 3D model. In addition, the quiet artificial Boundary Condition is used for the bottom of the foundation. While defining these Boundary Conditions, the special fish functions are created and defined to the software. Moreover, the hysteric damping coefficients are separately calculated for all of the materials. These special damping values are defined to the FLAC3D software using the special fish functions to capture the effects of the variation of the modulus and damping ratio with the dynamic shear-strain magnitude. In the numerical analyses, a total of 7 various strong far-fault earthquakes are used for the 3D nonlinear earthquake analyses, and 7 different numerical analyses are performed for the full-reservoir Condition of the Ilısu CFR dam. According to the seismic results, the principal stresses for the three critical nodal points on the dam body surface are examined and evaluated in detail. It is clearly understood that the nonlinear seismic behaviour of the Ilısu dam changes depending on the magnitudes and periods of the far-fault earthquakes. Each far-fault earthquake has different seismic effects on the nonlinear principal stress behaviour of the Ilısu CFR dam