双台子河闸闸墩混凝土结构温度应力仿真分析

发布时间：2018-06-05 07:28

本文选题：仿真分析 + 温度应力　；参考：《沈阳农业大学》2017年硕士论文

【摘要】：水闸闸墩产生裂缝,是一个较为普遍的现象,尤其是在东北地区受寒潮作用下的闸墩,保温不当或没有进行保温,闸墩很容易开裂。本文结合双台子河闸闸墩开裂实例,对开裂闸墩的温度场和应力场进行了较为深入的研究。主要研究成果如下:(1)针对双台子河闸施工期闸墩出现裂缝的情况,应用ANSYS软件,利用APDL语言编制仿真程序进行闸墩从浇筑至发现开裂整个过程的温度场及应力场仿真计算,从而发现受寒潮作用期间的仿真精度不高。(2)针对仿真计算受寒潮作用闸墩的温度应力精度不高的问题,基于子模型法进行寒潮作用下的闸墩热-应力耦合分析。结果表明,子模型法的应用提高了仿真计算的精度,网格划分重点突出且划分难度不大。模拟分析发现,由于寒潮作用及底板约束产生的温度应力使得闸墩在拆模后第105d时表面出现裂缝,造成闸墩开裂的直接原因是越冬期间混凝土未采取保温措施。(3)子模型法的应用虽提高了计算精度,但计算速度并没有得到提高,对此在计算闸墩混凝土随时间变化的温度和应力时将子母模型联合反馈修正算法应用于其中,在较为准确地模拟出结果的同时提高了仿真计算速度。(4)分别应用PSO-RBF神经网络和单一的RBF神经网络模拟和预测闸墩混凝土表面裂缝宽度,并进行比较分析,结果表明,PSO-RBF神经网络比单一的RBF神经网络收敛性更好,预测精度更高,可用于闸墩混凝土表面裂缝宽度的预测。(5)运用断裂力学方法对裂缝的发展趋势、稳定性等进行预测分析,并探讨了裂缝的危害性及温控防裂措施。
[Abstract]:It is a common phenomenon that the sluice pier produces crack, especially in the northeast area under the action of cold wave, the pier is easy to crack if the heat preservation is improper or not. In this paper, the temperature field and stress field of the cracked pier are studied with the example of cracking of Shuangtaizihe sluice pier. The main research results are as follows: (1) in view of the cracks in the pier during the construction period of Shuangtaizihe sluice, the temperature field and stress field of the pier from pouring to discovering cracking are simulated by using ANSYS software and APDL language. It is found that the accuracy of simulation during cold wave is not high. (2) in order to solve the problem that the precision of temperature stress of pier subjected to cold wave is not high, the thermal-stress coupling analysis of sluice pier under cold wave is carried out based on sub-model method. The results show that the accuracy of simulation is improved by the application of submodel method. The simulation results show that due to the effect of cold wave and the temperature stress caused by the restraint of the bottom plate, cracks appear on the surface of the pier at 105d after removing the mould. The direct cause of pier cracking is that the concrete does not take insulation measures. The application of the sub-model method improves the accuracy of calculation, but the calculation speed is not improved. In order to calculate the temperature and stress of pier concrete with time, the combined feedback correction algorithm of sub-mother model is applied to it. The PSO-RBF neural network and the single RBF neural network are used to simulate and predict the crack width of concrete surface of pier respectively. The results show that the PSO-RBF neural network has better convergence and higher prediction accuracy than the single RBF neural network. It can be used to predict the crack width on the concrete surface of the pier. The fracture mechanics method is used to predict the development trend and stability of the crack. The harmfulness of cracks and temperature control and crack prevention measures are also discussed.
【学位授予单位】：沈阳农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TV544

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