二次预应力组合梁简化计算方法分析

摘要

二次预应力梁有效地解决了超薄梁反拱过大、反向开裂等问题，为了进一步简化二次梁承载力的计算，以常用中小跨径二次预应力组合结构简支梁为研究对象，结合二次预应力组合结构的受力特点，基于组合结构理论，提出二次预应力梁极限承载力的简化计算分析方法。二次梁的一期梁预应力构件的作用是改善混凝土的脆性性能，提高一期梁的抗拉强度，因此将一期梁作为一种“特殊材料”的混凝土梁，通过受力分析得出其应力应变关系，推导出二次梁的简化计算公式。并使用有限元软件ANSYS对二次梁的受力过程进行数值模拟，与理论计算进行对比分析，验证了理论计算的准确性。%Twice pre-stressed beam can effectively solve problems like oversize ultra-thin beam arch and reverse cracking. In order to further simplify the calculation of bearing capacity of twice pre-stressed beam, this paper takes commonly used medium and small span simple beam about twice pre-stressed combination structure as the research object, and proposes the simplified calculation methods of ultimate bearing capacity about twice pre-stressed combination structure combining with the characteristics of twice pre-stressed beam based on the theory of composite structures. The role of the first phase of the beam is to improve the brittleness of concrete performance and increase tensile strength. Therefore, the first phase beam is taken as a kind of"special material"concrete beam to infer the simplified calculation formula through stress analysis of the first phase beam stress-strain relationship. The finite element software ANSYS is adopted to conduct numerical simulation and comparative analysis with the theoretical calculation to verify the accuracy of the theoretical formula.