Abaqus平台下混凝土坝地震响应的FEM-SBFEM联合计算

发布时间：2018-09-04 06:14

【摘要】：大坝-库水动力相互作用是混凝土坝在强震作用下动力响应的重要影响因素之一。合理地确定坝面在地震作用下的动水压力及其对坝体地震响应的影响是大坝安全评估的重要基础。目前,工程上用的Westergaard附加质量法和数值方法如有限元法在计算模型的精度及效率等方面仍未能很好的满足工程应用的需要。本文利用比例边界有限元方法(SBFEM)计算地震作用下的动水压力,然后将动水压力作为荷载施加在基于Abaqus有限元平台建立的坝体数值模型上,通过比例边界有限元和有限元联合计算,分析和比较了不同工况下的坝体地震响应。主要内容如下：(1)用Fortran语言编写的计算程序分别计算了Westergaard、Chopra数值解和SBFEM法的地震作用下动水压力并加以比较,验证了SBFEM法的正确性；(2)利用大型有限元计算软件Abaqus分别计算了Westergaard基于附加质量法和SBFEM动水压力法的地震坝体弹性响应和塑性损伤响应,给出了计算结果。由于SBFEM方法具有可以对求解域降维求解,且可以考虑库水的压缩性和库底吸收等影响因素的优点,相对上述其它有限元方法,FEM-SBFEM联合方法明显提高了计算效率和计算结果的精度；(3)利用FEM-SBFEM联合计算方法,探讨了不同(水体可压缩性、坝体高度、坝体厚度、库底吸收等)工况下坝体地震应力、位移响应和塑性损伤区域。研究成果对混凝土坝体建设和抗震安全评价具有参考价值。
[Abstract]:The dam-reservoir hydrodynamic interaction is one of the most important factors affecting the dynamic response of concrete dams under strong earthquakes. It is an important basis for dam safety assessment to reasonably determine the dynamic water pressure of dam face under earthquake and its influence on the seismic response of dam body. At present, the Westergaard additional mass method and numerical method, such as finite element method, can not meet the need of engineering application in the accuracy and efficiency of the model. In this paper, the proportional boundary finite element method (SBFEM) is used to calculate the dynamic water pressure under earthquake, and then the dynamic water pressure is applied as a load to the dam body numerical model based on the Abaqus finite element platform. The seismic responses of the dam under different working conditions are analyzed and compared by the finite element method and the finite element method. The main contents are as follows: (1) the calculation program written in Fortran language calculates the dynamic water pressure under the action of Westergaard,Chopra numerical solution and SBFEM method respectively and compares it to verify the correctness of SBFEM method; (2) the elastic response and the plastic damage response of the seismic dam based on the additional mass method and the SBFEM hydrodynamic pressure method are calculated by using the large finite element calculation software Abaqus, respectively, and the calculated results are given. Because the SBFEM method has the advantages of reducing the dimension of the solution domain and considering the influence factors such as the compressibility of the reservoir water and the absorption of the reservoir bottom, the calculation efficiency and the accuracy of the calculation results are improved obviously compared with the other finite element method (FEM-SBFEM) mentioned above. (3) the seismic stress, displacement response and plastic damage area of the dam under different conditions (water compressibility, dam height, dam thickness, bottom absorption, etc.) are discussed by using FEM-SBFEM method. The research results have reference value for concrete dam construction and seismic safety evaluation.
【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV642;TV312

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