共查询到18条相似文献,搜索用时 984 毫秒
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结合结构-地基动力相互作用数值分析的最新发展,在集总参数场地动力简化模型的框架内,提出了一种便于非均质场地条件采用的核电站厂房时频域动力分析的新模式。该模式利用谐响应法求解场地真实频域动阻抗曲线,利用混合变量模型保证频域动刚度的时域无损转换,实现楼层谱的全时域计算。最后,以某百万千万级核电站反应堆厂房的抗震分析为例,开展均质与非均质场地条件下动刚度及上部结构楼层谱计算的对比研究,验证了该分析方法的精度与应用效果。计算结果表明,比较均质场地条件,水平成层非均质场地条件下竖直方向楼层谱峰值有较大幅度改变,必须在核电抗震安全评价中加以重视。 相似文献
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利用人工地震波生成算法,探讨考虑土壤-结构相互作用的核电厂电气厂房地震响应动力分析模型和计算方法。通过比较楼层反应谱,研究岩土材料参数和载荷的不确定性对结构响应的影响。结果表明:岩土材料参数对核电厂电气厂房地震响应的影响更大,单一岩土材料参数下计算得到的拓宽后的楼层反应谱不能完全包络参数变化带来的地震响应差别。即使最终的反应谱大于或等于各种不同岩土参数下的楼层反应谱,仍有必要对不同岩土参数下的楼层反应谱做包络。 相似文献
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考虑SSI效应的核电站厂房楼层反应谱对比分析 总被引:1,自引:0,他引:1
在集总参数表征的场地动阻抗框架内,国内外主要核电厂抗震设计规范均推荐单一常系数弹簧-阻尼器并联体系表征均质场地动力模型。结合土-结构相互作用数值分析的最新发展,本文以CPR1000型反应堆厂房的集中质量简化模型作为研究对象,基于ASCE4-98规范、RCC-G规范、集10参数等适用于均质场地的集总参数地基模型以及适用于非均质复杂场地的粘弹性人工边界场地模型,开展了直接法和阻抗子结构法两种时程分析方法的对比研究,并将得到的楼层加速度反应谱与SASSI程序计算结果进行对比,互相验证了不同地基动力数值模型以及计算方法的有效性,对于评价核电厂地基适应性具有一定的指导与参考意义。 相似文献
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土壤-结构相互作用(SSI)会影响核电厂厂房的地震响应。本文充分考虑SSI效应的影响,对10 MW高温气冷堆(HTR-10)厂房在三向地震载荷下的响应进行了分析。建立了土壤-结构耦合有限元模型,通过构造人工边界实现对地震波在无限域内传播过程的模拟,并对模型的准确性进行了验证。利用该模型计算了HTR-10厂房的地震响应,并对不同楼层的反应谱计算结果进行了分析。对于水平向反应谱,各楼层的反应谱谱型类似,SSI影响规律基本一致。在竖直方向上,结构的响应特点与楼板自身的竖向频率特性有明显关系,不同楼板的响应差别较大。一般情况下,SSI效应对竖向响应有抑制作用,且随着楼层增加更为明显。当楼板与土壤的固有频率接近时,竖向响应与其他楼层相比会有显著放大。 相似文献
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大亚湾核电厂核反应堆厂房的抗震分析基本沿用法国M310型机组的标准分析方法(RCC—G),对于土-结构相互作用(SSI)效应的考虑,采用简化的阻抗函数法。本文拟采用新的相对精确的基于Green函数的三维连续半空间边界子结构法考虑地基岩土的作用,进行SSI耦合系统的地震响应分析计算,并将计算的楼层反应谱(FRS)同设计值进行比较,对设计方法及其结果的趋向性(偏于安全/或不安全)进行评估。结果表明,与基于三维连续半空间边界子结构法的计算结果相比较,电厂设计偏于安全。 相似文献
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A practical method to calculate the elasto-plastic seismic response of structures considering the dynamic soil-structure interaction is presented. The substructure technique in the time domain is utilized in the proposed method. A simple soil spring system with the coupling effects which are usually evaluated by the impedance matrix is introduced to consider the soil-structure interaction for embedded structures. As a numerical example, the response of a BWR-MARK II type reactor building embedded in the layered soil is calculated. The accuracy of the present method is verified by comparing its numerical results with exact solutions. The nonlinear behavior and the soil-structure interaction effects on the response of the reactor building are also discussed in detail. It is concluded that the present method is effective for the seismic design considering both the material nonlinearity of the nuclear reactor building and the dynamic soil-structure interaction. 相似文献
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Comparison of results of soil-structure interaction analyses of the reactor building of a nuclear power plant using different analytical approaches and solution procedures is presented. The emphasis of the comparison was on the treatment of damping in these different approaches and procedures. An axisymmetric model of the reactor building was employed. The analyses were performed for the aircraft impact loadings. Two different locations were used for these loadings.The following four different sets of analyses were performed.
- 1. (1) Time-domain analysis using frequency-independent soil springs in conjunction with modal damping cut-off.
- 2. (2) Frequency-domain analysis using frequency-independent soil springs in conjunction with a complex modulus approach.
- 3. (3) Frequency-domain analysis using frequency-dependent soil-impedance coefficients in conjunction with a complex modulus approach.
- 4. (4) Frequency-domain analysis using frequency-dependent soil-impedance coefficients in conjunction with Rayleigh damping.
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This paper presents an accurate three-dimensional seismic soil–structure interaction analysis for large structures. The method is applied to the fuel building in nuclear power plants. The analysis is performed numerically in the frequency domain and the responses are obtained by inverse Fourier transformation. The size of the structure matrices is reduced by transforming the equation of motion to the modal coordinate system. The soil is simulated as a layered media on top of viscoelastic half space. Soil impedance matrices are calculated from the principles of continuum mechanics and account for soil stiffness and energy dissipation. Effects of embedment on the field equations is incorporated through the scattering matrices or by simply scaling the soil impedance. Finite element methods are used to discretize the concrete foundation for the generation of the soil interaction matrices. Decoupling of the sloshing water in the spent fuel pools and the free-standing spent fuel racks is simulated. The input seismic motions are defined by three artificial time history accelerations. These input motions are generated to match the ground design basis response spectra and the target power spectral density function. The methods described in this paper can handle arbitrary foundation layouts, allows for large structural models, and accurately represents the soil impedance. Time history acceleration responses were subsequently used to generate floor response spectra at applicable damping values. 相似文献
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在考虑土-结构相互作用(SSI)效应的情况下,引入随机地震反应分析方法,探讨地基岩土参数的不确定性对核电厂地震响应的影响.基于ANSYS程序,采用常数阻抗法,通过设置边界弹簧和阻尼来考虑地基土的作用,并通过设置弹簧和阻尼参数的不确定性,来模拟岩土动态参数的不确定性.针对某1000MW级压水堆核电站反应堆厂房结构,进行随机地震反应的数值仿真分析,并将随机反应结果与确定论分析结果进行了对比.结果表明,随机分析方法是确定论分析方法的有益补充,二者结合能更合理地反映参数的不确定性对结构地震响应的影响. 相似文献
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A computational scheme for the development of non-linear floor response spectra is presented. Results in the case of an assumed missile impact on a reactor building are shown. Expected reductions, with respect to the linear case, for seismic or missile impact excitations are discussed. 相似文献
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Finite element modeling of the AP1000 nuclear island for seismic analyses at generic soil and rock sites 总被引:1,自引:0,他引:1
Leonardo Tun-Sanjur Richard S. Orr Sener Tinic Diego Pea Ruiz 《Nuclear Engineering and Design》2007,237(12-13):1474-1485
The AP1000 is a standard design developed by Westinghouse and its partners for an advanced nuclear power plant utilizing passive safety features. The design has been certified by the US Nuclear Regulatory Commission based on their review of seismic analyses at hard rock sites. The plant has five principal building structures: the nuclear island, the turbine building, the annex building, the diesel generator building and the radwaste building. The nuclear island consists of the containment building (the steel containment vessel and the containment internal structures), the shield building and the auxiliary building. These structures are founded on a common basemat and are collectively known as the nuclear island. This paper describes shell and stick finite element models used in fixed base dynamic analyses for the hard rock design certification using the general purpose finite element program ANSYS. It describes a coarser shell model developed for use in soil structure interaction (SSI) analyses. This model is developed in both ANSYS and the soil structure interaction (SSI) program SASSI. Results of the three types of models from ANSYS analyses are compared for a hard rock site. Results are also compared between the ANSYS and SASSI analyses for the same model. 相似文献
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A study on the connection effects of subsurface slabs to exterior walls in the KNGR seismic analysis
The soil-structure interaction (SSI) analyses are being performed for the Korean next generation reactor (KNGR) design, because the KNGR is developed as a standard nuclear power plant concept enveloping various soil conditions. The SASSI program, which adopts the flexible volume method is used for the SSI analyses. Since the impedances are computed based on the assumption of a rigid foundation in the KNGR design, the impedances are computed at a single point around the center of the basemat. The base model used in the SSI analyses assumed that the subsurface slabs are free and not connected to the exterior walls. This results in a more flexible structure than reality. This study is performed to address the concern of the potential dynamic effect of this modeling assumption on the overall structural response. The super-structure model is modified with the subsurface portions of the sticks being laterally rigid, so that the entire subsurface cavity together with the super-structure model acts laterally rigid. For the comparison, the in-structure response spectra using the rigid subsurface model are compared with the original spectra without considering the connection effects. 相似文献