材料参数对拱坝非线性响应的敏感性分析

发布时间：2018-03-24 18:09

本文选题：拱坝　切入点：材料非线性　出处：《昆明理工大学》2014年硕士论文

【摘要】：通过总结国内外学者关于拱坝非线性问题对材料敏感性分析这一课题的研究成果、主要的研究方法和发展现状,选定材料非线性问题拱坝受力情况对D-P材料参数敏感性分析作为本文的研究课题。主要是对拱坝基本组合的正常蓄水位温升温降工况进行弹塑性计算,并且对拱坝的Y向位移、最大拉应力、最大压应力及塑性区发展进行了敏感性分析,对实际工程具有一定的意义。空心球体热-结构耦合场理论解与数值解的对比表明：相对误差各点不一,但全局能量误差泛数为0.426%,说明得到的数值解是可靠的；网格划分为映射划分六面体单元时,比自由划分结果要好；单元尺寸宜为0.25倍球体厚度。对拱坝进行计算表明：大部分区域的计算结果误差均很小,坝体能量误差泛数小于11.6%。粘聚力不变,内摩擦角增大时分析表明：两种工况的共性是塑性区明显减少,最大等效塑性应变减小,发生在上游坝底；坝体第一主应力明显减小,最大值发生在上游坝底；坝体Y方向最大值均发生在上游坝顶中部和下游坝底中部。不同之处是在温升工况,第三主应力明显减小,最大值发生在下游右岸坝底；坝体Y方向位移略有减小,但变化不明显；在温降工况,第三主应力明显减小,最大值发生在上游右岸坝底；坝体Y方向位移明显减小。内摩擦角不变,粘聚力减小时分析表明：两种工况的共性是塑性区略有增大,最大等效塑性应变增大,发生在上游坝底略偏左岸；坝体第一主应力无明显变化,最大值发生在上游坝底偏左岸。不同的是温升工况,第三主应力变化无明显趋势,最大值发生在上游左岸坝底；坝体Y方向位移变化无明显趋势,最大值均发生在上游坝顶中部和下游坝底中部。温降工况,第三主应力明显增大,最大值发生在上游右岸坝底；坝体Y方向位移变化增大,最大值均发生在上游坝顶中部和下游坝底中部。对比分析表明：温升工况,下游坝底中部的Y方向位移最大值大于上游坝顶中部Y方向位移最大值；温降工况与之相反；塑性区的范围发生在上游坝底及左右岸的地方,最大等效塑性应变通常出现在上游左岸坝底。但内摩擦角的变化对塑性区发展、第一主应力、坝体Y方向位移影响更敏感；粘聚力的变化对第三主应力、坝体Y方向位移影响敏感。工程中需加以注意。
[Abstract]:By summing up the research achievements, main research methods and development status of the research on the material sensitivity analysis of the nonlinear problem of arch dam, The sensitivity analysis of D-P material parameter to the stress of arch dam with material nonlinear problem is selected as the research topic in this paper. The elastic-plastic calculation of the normal temperature and temperature drop condition of the normal storage water level and the Y direction displacement of the arch dam are carried out. The sensitivity analysis of the maximum tensile stress, the maximum compressive stress and the development of the plastic zone is of certain significance to the practical engineering. The comparison between the theoretical and numerical solutions of the thermal-structural coupling field of the hollow sphere shows that the relative error varies from point to point, but the universal number of global energy errors is 0.426, which shows that the obtained numerical solution is reliable, and the meshes are mapped to divide hexahedron elements. The element size should be 0.25 times the thickness of the sphere. The calculation of the arch dam shows that the error of the calculation results in most areas is very small, and the energy error of the dam is less than 11.6. When the cohesive force is constant and the angle of internal friction increases, it is shown that the common features of the two conditions are that the plastic zone is obviously reduced, the maximum equivalent plastic strain is reduced, which occurs at the bottom of the upstream dam, the first principal stress of the dam body decreases obviously, and the maximum value occurs at the bottom of the upstream dam. The maximum Y direction of the dam body occurs in the middle of the upstream dam top and the middle of the downstream dam bottom. The difference is that in the temperature rise condition, the third principal stress obviously decreases, the maximum occurs at the bottom of the downstream right bank dam, and the Y direction displacement of the dam body decreases slightly. Under the condition of temperature drop, the third principal stress decreases obviously, the maximum occurs at the bottom of the upstream right bank dam, and the Y direction displacement of the dam body decreases obviously. When the angle of internal friction is constant and the cohesive force is reduced, the results show that the plastic zone increases slightly and the maximum equivalent plastic strain increases, which occurs on the left bank of the bottom of the upstream dam, and the first principal stress of the dam body has no obvious change. The maximum value occurs on the left bank of the bottom of the upstream dam. The temperature rise condition is different, the change of the third principal stress has no obvious trend, the maximum value occurs at the bottom of the dam in the left bank of the upstream, and there is no obvious trend in the change of Y direction displacement of the dam body. The maximum value occurs in the middle of the upstream dam top and the middle of the downstream dam bottom. Under the condition of temperature drop, the third principal stress increases obviously, the maximum occurs at the bottom of the dam in the right bank of the upstream, and the Y direction displacement of the dam body increases. The maximum occurred in the middle of the upstream dam top and the middle of the downstream dam bottom. The comparative analysis shows that the maximum value of Y direction displacement in the middle of downstream dam bottom is greater than the maximum Y direction displacement in the middle of upstream dam top, the temperature drop condition is opposite to the temperature rise condition, and the range of plastic zone occurs at the bottom of upstream dam and on the left and right bank. The maximum equivalent plastic strain usually appears at the bottom of the upstream left bank dam, but the change of the angle of internal friction is more sensitive to the development of the plastic zone, the first principal stress and the Y direction displacement of the dam body, and the change of cohesive force is more sensitive to the third principal stress. The influence of Y direction displacement on dam body is sensitive. Attention should be paid to it in engineering.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV642.4

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