The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Runzi Wang - One of the best experts on this subject based on the ideXlab platform.
-
time dependent Failure Probability estimation of the solid oxide fuel cell by a creep damage related weibull distribution model
International Journal of Hydrogen Energy, 2018Co-Authors: Yucai Zhang, Wenchun Jiang, Huiqin Zhao, Shantung Tu, Xiancheng Zhang, Runzi WangAbstract:Abstract In present paper, a new model is proposed and embedded into the finite element software ABAQUS to estimate the time dependent Failure Probability of the solid oxide fuel cell stack. The results show that sealant is the potential Failure region of the solid oxide fuel cell stack, while the Failure Probability of the anode, electrolyte and cathode are very small within the operation time of 50,000 h. The creep and damage distribution of the components reflect that the proposed model can reasonably predict the time dependent Failure Probability of the solid oxide fuel cell stack. Increasing either the characteristic strain, Weibull modulus or decreasing the operating temperature can decrease the Failure Probability of the SOFC stack. For the sealant, to ensure the high temperature integrity of the SOFC stack, the characteristic strain should be larger than 0.01 or Weibull modulus should be higher than 8.0 under the operating temperature of 600 °C.
Wenchun Jiang - One of the best experts on this subject based on the ideXlab platform.
-
time dependent Failure Probability estimation of the solid oxide fuel cell by a creep damage related weibull distribution model
International Journal of Hydrogen Energy, 2018Co-Authors: Yucai Zhang, Wenchun Jiang, Huiqin Zhao, Shantung Tu, Xiancheng Zhang, Runzi WangAbstract:Abstract In present paper, a new model is proposed and embedded into the finite element software ABAQUS to estimate the time dependent Failure Probability of the solid oxide fuel cell stack. The results show that sealant is the potential Failure region of the solid oxide fuel cell stack, while the Failure Probability of the anode, electrolyte and cathode are very small within the operation time of 50,000 h. The creep and damage distribution of the components reflect that the proposed model can reasonably predict the time dependent Failure Probability of the solid oxide fuel cell stack. Increasing either the characteristic strain, Weibull modulus or decreasing the operating temperature can decrease the Failure Probability of the SOFC stack. For the sealant, to ensure the high temperature integrity of the SOFC stack, the characteristic strain should be larger than 0.01 or Weibull modulus should be higher than 8.0 under the operating temperature of 600 °C.
-
effects of anode porosity on thermal stress and Failure Probability of planar solid oxide fuel cell with bonded compliant seal
International Journal of Hydrogen Energy, 2016Co-Authors: Yun Luo, Wenchun Jiang, Qian Zhang, Weiwen Zhang, Muming HaoAbstract:Abstract The effects of anode porosity on thermal stress and Failure Probability of a planar solid oxide fuel cell (SOFC) are investigated by finite element method (FEM). The thermal stress and Failure Probability in planar SOFC with and without considering porosity (CP) were compared. The results show that the compressive stresses are generated in the electrolyte layer, while tensile stresses are generated in Ag–CuO and BNi2 layer because of the compatibility of deformation. In the case of considering anode porosity, the compressive stresses in anode and electrolyte layer and the tensile stresses in cathode layer are all decreased. Comparing to without CP, the thermal stress with CP in electrolyte and cathode layer decreases by 33.2% and 46.9%, respectively. The anode layer has a large risk of Failure (5.6489 × 10 −4 ) than that of cathode and electrolyte layer at as-fabricated state. And the Failure Probability at cathode layer at start-up reaches 0.998. The Failure Probability decreases gradually in the period of creep. The Failure Probability in anode, cathode and electrolyte layer with CP all decrease comparing to without CP. The porosity of anode could lead to the decrease of tensile thermal stress, resulting in the decrease of Failure Probability in cathode layer. The reduction speed of Failure Probability at creep stage with CP is bigger than that without CP. As the increase of porosity, the Failure Probability decreases due to the decrease of the tensile stress.
Yucai Zhang - One of the best experts on this subject based on the ideXlab platform.
-
time dependent Failure Probability estimation of the solid oxide fuel cell by a creep damage related weibull distribution model
International Journal of Hydrogen Energy, 2018Co-Authors: Yucai Zhang, Wenchun Jiang, Huiqin Zhao, Shantung Tu, Xiancheng Zhang, Runzi WangAbstract:Abstract In present paper, a new model is proposed and embedded into the finite element software ABAQUS to estimate the time dependent Failure Probability of the solid oxide fuel cell stack. The results show that sealant is the potential Failure region of the solid oxide fuel cell stack, while the Failure Probability of the anode, electrolyte and cathode are very small within the operation time of 50,000 h. The creep and damage distribution of the components reflect that the proposed model can reasonably predict the time dependent Failure Probability of the solid oxide fuel cell stack. Increasing either the characteristic strain, Weibull modulus or decreasing the operating temperature can decrease the Failure Probability of the SOFC stack. For the sealant, to ensure the high temperature integrity of the SOFC stack, the characteristic strain should be larger than 0.01 or Weibull modulus should be higher than 8.0 under the operating temperature of 600 °C.
Dongbin Xiu - One of the best experts on this subject based on the ideXlab platform.
-
an efficient surrogate based method for computing rare Failure Probability
Journal of Computational Physics, 2011Co-Authors: Dongbin XiuAbstract:In this paper, we present an efficient numerical method for evaluating rare Failure Probability. The method is based on a recently developed surrogate-based method from Li and Xiu [J. Li, D. Xiu, Evaluation of Failure Probability via surrogate models, J. Comput. Phys. 229 (2010) 8966-8980] for Failure Probability computation. The method by Li and Xiu is of hybrid nature, in the sense that samples of both the surrogate model and the true physical model are used, and its efficiency gain relies on using only very few samples of the true model. Here we extend the capability of the method to rare Probability computation by using the idea of importance sampling (IS). In particular, we employ cross-entropy (CE) method, which is an effective method to determine the biasing distribution in IS. We demonstrate that, by combining with the CE method, a surrogate-based IS algorithm can be constructed and is highly efficient for rare Failure Probability computation-it incurs much reduced simulation efforts compared to the traditional CE-IS method. In many cases, the new method is capable of capturing Failure Probability as small as 10^-^1^2~10^-^6 with only several hundreds samples.
-
evaluation of Failure Probability via surrogate models
Journal of Computational Physics, 2010Co-Authors: Dongbin XiuAbstract:Evaluation of Failure Probability of a given system requires sampling of the system response and can be computationally expensive. Therefore it is desirable to construct an accurate surrogate model for the system response and subsequently to sample the surrogate model. In this paper we discuss the properties of this approach. We demonstrate that the straightforward sampling of a surrogate model can lead to erroneous results, no matter how accurate the surrogate model is. We then propose a hybrid approach by sampling both the surrogate model in a ''large'' portion of the Probability space and the original system in a ''small'' portion. The resulting algorithm is significantly more efficient than the traditional sampling method, and is more accurate and robust than the straightforward surrogate model approach. Rigorous convergence proof is established for the hybrid approach, and practical implementation is discussed. Numerical examples are provided to verify the theoretical findings and demonstrate the efficiency gain of the approach.
Xiancheng Zhang - One of the best experts on this subject based on the ideXlab platform.
-
time dependent Failure Probability estimation of the solid oxide fuel cell by a creep damage related weibull distribution model
International Journal of Hydrogen Energy, 2018Co-Authors: Yucai Zhang, Wenchun Jiang, Huiqin Zhao, Shantung Tu, Xiancheng Zhang, Runzi WangAbstract:Abstract In present paper, a new model is proposed and embedded into the finite element software ABAQUS to estimate the time dependent Failure Probability of the solid oxide fuel cell stack. The results show that sealant is the potential Failure region of the solid oxide fuel cell stack, while the Failure Probability of the anode, electrolyte and cathode are very small within the operation time of 50,000 h. The creep and damage distribution of the components reflect that the proposed model can reasonably predict the time dependent Failure Probability of the solid oxide fuel cell stack. Increasing either the characteristic strain, Weibull modulus or decreasing the operating temperature can decrease the Failure Probability of the SOFC stack. For the sealant, to ensure the high temperature integrity of the SOFC stack, the characteristic strain should be larger than 0.01 or Weibull modulus should be higher than 8.0 under the operating temperature of 600 °C.
