The Experts below are selected from a list of 54036 Experts worldwide ranked by ideXlab platform
H Zhang - One of the best experts on this subject based on the ideXlab platform.
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Seismic performance evaluation of large-span offshore cable-stayed bridges under non-uniform earthquake excitations including Strain Rate Effect
Science China Technological Sciences, 2020Co-Authors: H Zhang, Ding YimingAbstract:This paper presents a novel and precise seismic performance evaluation method for large-span offshore cable-stayed (LSOCS) bridge by considering the Strain Rate Effect of RC materials and the spatial variation Effect of seafloor seismic motions. Three-dimensional finite element (FE) model of a LSOCS bridge located in the southeast coast of China is constructed in the ABAQUS platform. The non-uniform ground motions at the offshore site beneath the bridge are stochastically simulated and used as seismic inputs. Moreover, a subroutine for considering the Rate-dependent properties of RC materials in a fiber-based beam-column element model is developed to account for the Strain Rate Effect of RC materials in the nonlinear time-history analysis. The numerical results indicate that seismic responses and fragilities of the LSOCS bridge are both considerably affected by the non-uniform seafloor seismic motions and Strain Rate Effect. The seismic performance evaluation approach presented in this paper can provide vital support for earthquake resistant design of LSOCS bridges.
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Experimental and numerical investigations on seismic responses of reinforced concrete structures considering Strain Rate Effect
Construction and Building Materials, 2018Co-Authors: H Zhang, Guang-wei CaoAbstract:Abstract The Strain Rate Effect can inevitably impact the seismic responses of reinforced concrete (RC) structures because the dynamic properties of RC materials under earthquakes change significantly with the time-varying loading Rates. This paper carries out systematic experimental tests and numerical simulations to investigate the Effects of Strain Rates on the seismic responses of RC structures. The dynamic properties of micro-concrete and iron wire used in the shaking table specimen are firstly tested under seismic loading Rates and the corresponding dynamic increase factors (DIFs) are estimated based on the test data. The shaking table test of a 1/5 scaled RC structure is performed to realistically reproduce the dynamic responses of RC structures with Strain Rate Effect. Moreover, a three-dimensional Rate-dependent fiber beam-column element is developed in the ABAQUS platform to establish the finite element (FE) model of the shaking table specimen, in which the estimated DIFs for the key parameters of micro-concrete and iron wire are employed to consider the Strain Rate Effect. Besides, the Rate-independent structural FE model is also developed using the traditional beam-column element with the static RC material constitutive models. The numerical results demonstRate that the seismic responses of RC structures are overestimated when the Strain Rate Effect is neglected. As validated by the experimental data of the shaking table test, the FE model developed using the proposed Rate-dependent fiber beam-column element can yield better structural seismic response predictions in comparison with the Rate-independent model.
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Dynamic analysis of reinforced concrete structure with Strain Rate Effect
Materials Research Innovations, 2011Co-Authors: H ZhangAbstract:In order to study the dynamic behaviour of reinforced concrete structures affected by Strain Rate Effect when subjected to seismic loading, the dynamic responses of the reinforced concrete shear wall and a three‐storey reinforced concrete frame were analysed with Abaqus finite element software. The Drucker‐Prager model and concrete damaged plasticity model were used, and the Strain Rate Effect of concrete and steel was also considered. Results showed that the dynamic behaviour of concrete and steel change greatly when the Strain Rate Effect is taken into account. For a reinforced concrete shear wall subjected to dynamic loading, there was an increase in load carrying capacity and stiffness. The results in the time history analysis of the reinforced concrete frame with the Strain Rate Effect are different from those without the Strain Rate Effect. Strain Rate Effects should be considered carefully in the seismic analysis of reinforced concrete structures.
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Study on Strain Rate Effect in High-Rise Reinforced Concrete Shear Wall Structure
Advanced Materials Research, 2011Co-Authors: H Zhang, Zhe WangAbstract:The dynamic behavior affected by Strain Rate Effect of the high-rise reinforced concrete shear wall structure subjected to seismic loading are analyzed by finite element software ABAQUS. The damaged plasticity model for concrete was used, and the Strain Rate Effect of concrete and steel were considered. The nonlinear dynamic response results with Strain Rate Effect are compared with the results without Strain Rate Effect. The distribution of Strain Rate can not only influence the concrete and steel, but also have some Effects on the dynamic response of the high-rise reinforced concrete shear wall structure. The Strain Rate Effect is more prominent under the stronger seismic wave.
Guichang Yang - One of the best experts on this subject based on the ideXlab platform.
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analysis of rc structures subjected to air blast loading accounting for Strain Rate Effect of steel reinforcement
International Journal of Impact Engineering, 2007Co-Authors: Guichang YangAbstract:A new method to calculate the dynamic strength of reinforced concrete (RC) structures, with emphasis on the embedded response of mild steel reinforcement, subjected to air-blast loading is derived. The proposed method is based on a single-degree-of-freedom (SDOF) system with appropriate modification for Strain-Rate Effect. Approximate formulae are used and explained in detail. A numerical example is presented to show how the derived formulae are used for the analysis of concrete structures subjected to air-blast loading.
Guang-wei Cao - One of the best experts on this subject based on the ideXlab platform.
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Experimental and numerical investigations on seismic responses of reinforced concrete structures considering Strain Rate Effect
Construction and Building Materials, 2018Co-Authors: H Zhang, Guang-wei CaoAbstract:Abstract The Strain Rate Effect can inevitably impact the seismic responses of reinforced concrete (RC) structures because the dynamic properties of RC materials under earthquakes change significantly with the time-varying loading Rates. This paper carries out systematic experimental tests and numerical simulations to investigate the Effects of Strain Rates on the seismic responses of RC structures. The dynamic properties of micro-concrete and iron wire used in the shaking table specimen are firstly tested under seismic loading Rates and the corresponding dynamic increase factors (DIFs) are estimated based on the test data. The shaking table test of a 1/5 scaled RC structure is performed to realistically reproduce the dynamic responses of RC structures with Strain Rate Effect. Moreover, a three-dimensional Rate-dependent fiber beam-column element is developed in the ABAQUS platform to establish the finite element (FE) model of the shaking table specimen, in which the estimated DIFs for the key parameters of micro-concrete and iron wire are employed to consider the Strain Rate Effect. Besides, the Rate-independent structural FE model is also developed using the traditional beam-column element with the static RC material constitutive models. The numerical results demonstRate that the seismic responses of RC structures are overestimated when the Strain Rate Effect is neglected. As validated by the experimental data of the shaking table test, the FE model developed using the proposed Rate-dependent fiber beam-column element can yield better structural seismic response predictions in comparison with the Rate-independent model.
Muhamamd Zakir - One of the best experts on this subject based on the ideXlab platform.
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Dynamic Fracture Process and Strain Rate Effect of a Porous SiC Ceramic
Proceedings, 2018Co-Authors: Yanpei Wang, Ding Zhou, Huifang Liu, Muhamamd ZakirAbstract:In this paper, dynamic fracture process and Strain Rate Effect of a porous SiC ceramic were investigated. The failure process under dynamic loading conditions was monitored by a high-speed camera. Digital image correlation (DIC) method was further utilized to calculate the surface Strain field. The high-speed images show that crack initiates in the center of the specimen and then propagates to the entire specimen under dynamic loading. In addition, DIC result showed that cracks occur on the surface of the specimen formed a band. And the band finally caused the collapse of the specimen. The test results showed that compressive strength of the porous SiC ceramic is Rate sensitive. Under quasi-static conditions, the compressive strength is about 120 MPa, while in dynamic conditions strength increased to 247 MPa. Energy absorption during the deformation process is much larger under dynamic loading.
Fenglei Huang - One of the best experts on this subject based on the ideXlab platform.
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Interaction between Crack and Aggregate in Concrete under Dynamic Tensile Loading and Strain-Rate Effect on Material Strength
Advanced Materials Research, 2011Co-Authors: Lu Guang Liu, Yan Liu, Zhuo-ping Duan, Fenglei HuangAbstract:Crack propagation behaviors at a mortar-aggregate interface in concrete under dynamic tensile loading conditions are investigated numerically. It is found, for a certain interfacial strength and aggregate size, that the crack can penetRate through the interface under an external load with its loading-Rate higher than a threshold value. Moreover, for the crack penetration, the smaller the radius of an aggregate, the higher the loading-Rate is needed. Therefore, concrete failure energy increase considerably with the loading-Rate (or the Strain-Rate). Such a Strain-Rate Effect on the strength of concrete is in agreement with previous experimental results.
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Analytical approach to the Strain Rate Effect on the dynamic tensile strength of brittle materials
International Journal of Impact Engineering, 2010Co-Authors: Zhuo-ping Duan, Fenglei HuangAbstract:Abstract An explicit mathematical expression for the dynamic load-carrying capacity of brittle materials under dynamic tensile loads is derived based on a kind of structural-temporal failure criterion [1] and the one-dimensional longitudinal plane wave propagation model. It is shown that the dependence of the dynamic load-carrying capacity on the Strain Rate can be determined only by the static material parameters such as tensile strength, density, incubation time, critical failure length and constitutive constants, which verifies that the well known Strain Rate Effect on material strength can be considered as an structural rather than material behavior, as pointed out by Cotsovos and Pavlovic [2] recently. Moreover, it is found that, under constant Strain Rate, the dynamic load-carrying capacity depends also on the amplitudes of imposed boundary loads, which explains, to a significant extent, the scatter that characterizes the available experimental data. Furthermore, the derived expression can also be used as a foundation of theoretical analyses on other problems involving the Strain Rate Effect such as dynamic size Effect, dynamic failure of quasi-brittle materials and composites.
