This paper proposes a new technique which introduces the high-order single-step-β method(HSM)into the experimental study on the substructure pseudo-dynamic testing(SPDT).The technique is based on the proposed concept...This paper proposes a new technique which introduces the high-order single-step-β method(HSM)into the experimental study on the substructure pseudo-dynamic testing(SPDT).The technique is based on the proposed concept of equivalent shear stiffness which can meet the requirement of the HSM algorithm.A study is done to theoretically validate the technique by the numerical analysis of two-storey shear building structure,in comparison of the proposed substructure pseudo-dynamic testing algorithm with the central difference method(CDM).Then,a full-scale SPDT model,the three-storey frame-supported reinforced concrete short-limb masonry shear wall structure,is designed and tested to simulate the seismic response of the corresponding six-storey structure and verify the proposed force control HSM technique.Meanwhile,the techniques of both stiffness correction and force control are suggested to control algorithmic error,control error and measurement error.The results indicate that the force control HSM can be used in the full-scale multi-degree-of-freedom(MDOF)substructure pseudo-dynamic testing before descent segment of structure restoring force properties.展开更多
In the zones of high seismic activity, tailings dam should be assessed for the stability against earthquake forces. In the present paper, a simplified method is proposed to compute the factor of safety of tailings dam...In the zones of high seismic activity, tailings dam should be assessed for the stability against earthquake forces. In the present paper, a simplified method is proposed to compute the factor of safety of tailings dams. The strain-dependent dynamic properties are used to assess the stability of tailings dams under seismic conditions. The effect of foundation soil properties on the seismic stability of tailings dams is studied using the proposed method. For the given input parameters, the factor of safety for lowfrequency input motions is nearly 26% lower than that for high-frequency input excitations. The impedance ratio and the depth of foundation have significant effect on the seismic factor of safety of tailings dams. The results from the proposed method are well compared with the existing pseudo-static method of analysis. Tailings dams are vulnerable to damage for low-frequency input motions.展开更多
Applications using higher orderharmonics (HOH) require knowledge ofthe completeness ofthe HOHfor the diffusion difference equation.This papershowsthatthe set of HOHforthefission sourceis complete ,butthat the setfor...Applications using higher orderharmonics (HOH) require knowledge ofthe completeness ofthe HOHfor the diffusion difference equation.This papershowsthatthe set of HOHforthefission sourceis complete ,butthat the setfortheflux usingthe multi group modelis notcomplete .This paperusesthe assumption thatthe set offlux vectors of HOHfor every group is complete. This assumption can be proven only forthose groups into which noscattering neutrons enter.However,itisalso shownto betrueforseveralpracticalreactor models.Analysisshows thatthe number of HOHwith non zero eigenvaluesis equaltothe numberofdifference meshes withfissile material, and thatthe eigenvalues have positive realvalues.This assumptionis valuablefor HOHapplications,butrequires furthertheoreticalstudyto verify whetheritisuniversally applicable.展开更多
基金Sponsored by the National Natural Science Foundation of China(Grant No.50508012)
文摘This paper proposes a new technique which introduces the high-order single-step-β method(HSM)into the experimental study on the substructure pseudo-dynamic testing(SPDT).The technique is based on the proposed concept of equivalent shear stiffness which can meet the requirement of the HSM algorithm.A study is done to theoretically validate the technique by the numerical analysis of two-storey shear building structure,in comparison of the proposed substructure pseudo-dynamic testing algorithm with the central difference method(CDM).Then,a full-scale SPDT model,the three-storey frame-supported reinforced concrete short-limb masonry shear wall structure,is designed and tested to simulate the seismic response of the corresponding six-storey structure and verify the proposed force control HSM technique.Meanwhile,the techniques of both stiffness correction and force control are suggested to control algorithmic error,control error and measurement error.The results indicate that the force control HSM can be used in the full-scale multi-degree-of-freedom(MDOF)substructure pseudo-dynamic testing before descent segment of structure restoring force properties.
文摘In the zones of high seismic activity, tailings dam should be assessed for the stability against earthquake forces. In the present paper, a simplified method is proposed to compute the factor of safety of tailings dams. The strain-dependent dynamic properties are used to assess the stability of tailings dams under seismic conditions. The effect of foundation soil properties on the seismic stability of tailings dams is studied using the proposed method. For the given input parameters, the factor of safety for lowfrequency input motions is nearly 26% lower than that for high-frequency input excitations. The impedance ratio and the depth of foundation have significant effect on the seismic factor of safety of tailings dams. The results from the proposed method are well compared with the existing pseudo-static method of analysis. Tailings dams are vulnerable to damage for low-frequency input motions.
文摘Applications using higher orderharmonics (HOH) require knowledge ofthe completeness ofthe HOHfor the diffusion difference equation.This papershowsthatthe set of HOHforthefission sourceis complete ,butthat the setfortheflux usingthe multi group modelis notcomplete .This paperusesthe assumption thatthe set offlux vectors of HOHfor every group is complete. This assumption can be proven only forthose groups into which noscattering neutrons enter.However,itisalso shownto betrueforseveralpracticalreactor models.Analysisshows thatthe number of HOHwith non zero eigenvaluesis equaltothe numberofdifference meshes withfissile material, and thatthe eigenvalues have positive realvalues.This assumptionis valuablefor HOHapplications,butrequires furthertheoreticalstudyto verify whetheritisuniversally applicable.
