混凝土结构有限元计算中预应力模拟方法及比较
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摘要
介绍了钢筋混凝土结构有限元分析中模拟预应力的方法并给出相关公式。以块体结构和预应力闸墩为例,对比了不同预应力模拟方法的差异。分析结果表明:荷载法计算精度受预应力筋矢跨比的影响,当矢跨比较大时会有较大误差;节点力法能够模拟任何曲率的预应力筋作用,网格划分合理时计算结果与考虑张拉过程的实体力筋法一致;对于非杆系预应力混凝土结构,需考虑混凝土开裂时应采用实体力筋法,否则可采用节点力法;采用实体力筋法模拟预应力作用时,是否考虑张拉过程对锚固端附近的混凝土压应力影响较大,对其它部位影响不明显。
Different simulation methods of pre- stress in FEM of reinforced structure are introduced and the relevant formulas are given,a block structure and a pre- stressed pier are taken as examples to compare the differences of these simulations. The analysis shows that the accuracy of loading method is affected by rise- span- ratio of the pre- stressed steel tendons and the error is large when the rise- span- ratio is large. Steel tendons with any curvature can be simulated by nodal force method and if the mesh is reasonably arranged,the result is approximately the same as the entitative rebar method that considers the stretching process. The entitative rebar method should be adopted if post- cracking behavior of mass concrete structures must be taken into consideration; otherwise,the nodal force method should be adopted. For entitative rebar method,whether the stretching process is considered or not has great influence on the concrete compressive stress near the anchor part but little effect on other area.
Different simulation methods of pre- stress in FEM of reinforced structure are introduced and the relevant formulas are given,a block structure and a pre- stressed pier are taken as examples to compare the differences of these simulations. The analysis shows that the accuracy of loading method is affected by rise- span- ratio of the pre- stressed steel tendons and the error is large when the rise- span- ratio is large. Steel tendons with any curvature can be simulated by nodal force method and if the mesh is reasonably arranged,the result is approximately the same as the entitative rebar method that considers the stretching process. The entitative rebar method should be adopted if post- cracking behavior of mass concrete structures must be taken into consideration; otherwise,the nodal force method should be adopted. For entitative rebar method,whether the stretching process is considered or not has great influence on the concrete compressive stress near the anchor part but little effect on other area.
引文
[1]陈然.拱坝预应力闸墩应力分析及厚度优化[D].郑州:华北水利水电大学,2013.
[2]赵顺波,李晓克,严振瑞,等.环形高效预应力混凝土技术与工程应用[M].北京:科学出版社,2008.
[3]周熙波.后张预应力混凝土结构预加力作用机理的分析研究[D].武汉:武汉理工大学,2004.
[4]张友科,傅倩.有粘结和无粘结预应力锚索在混凝土结构中的应用[J].西北水电,2007,(4):30-33.
[5]张耀庭,邱继生.ANSYS在预应力钢筋混凝土结构非线性分析中的应用[J].华中科技大学学报:城市科学版,2003,(4):20-23.
[6]张社荣,祝青,李升,等.大型渡槽数值分析中预应力的模拟方法[J].水力发电学报,2009,(3):97-100+90.
[7]孙乃波,傅少君,陈胜宏,等.碗米坡预应力闸墩三维有限元分析[J].水电能源科学,2005,(3):74-76+94.
[8]汪基伟,张雄文.水工钢筋混凝土结构有限元设计计算原则[J].水利水电科技进展,2005,(5):48-51.
[9]汪基伟,张雄文,林新志,等.考虑粘结滑移的平面组合式单元模型研究与应用[J].工程力学,2008,(1):97-102+108.
[10]Mirza M S,Houd J.Study of bond stress-slip relationships in reinforced concrete[J].ACI Structural Journal,1979,76(1):19-46.
[2]赵顺波,李晓克,严振瑞,等.环形高效预应力混凝土技术与工程应用[M].北京:科学出版社,2008.
[3]周熙波.后张预应力混凝土结构预加力作用机理的分析研究[D].武汉:武汉理工大学,2004.
[4]张友科,傅倩.有粘结和无粘结预应力锚索在混凝土结构中的应用[J].西北水电,2007,(4):30-33.
[5]张耀庭,邱继生.ANSYS在预应力钢筋混凝土结构非线性分析中的应用[J].华中科技大学学报:城市科学版,2003,(4):20-23.
[6]张社荣,祝青,李升,等.大型渡槽数值分析中预应力的模拟方法[J].水力发电学报,2009,(3):97-100+90.
[7]孙乃波,傅少君,陈胜宏,等.碗米坡预应力闸墩三维有限元分析[J].水电能源科学,2005,(3):74-76+94.
[8]汪基伟,张雄文.水工钢筋混凝土结构有限元设计计算原则[J].水利水电科技进展,2005,(5):48-51.
[9]汪基伟,张雄文,林新志,等.考虑粘结滑移的平面组合式单元模型研究与应用[J].工程力学,2008,(1):97-102+108.
[10]Mirza M S,Houd J.Study of bond stress-slip relationships in reinforced concrete[J].ACI Structural Journal,1979,76(1):19-46.