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基于通用有限元软件的二次开发功能,综合考虑先张预应力传递机理、混凝土徐变效应以及材料非线性的影响,对空心板梁生产、存放、施工、正常使用和破坏的全过程进行模拟。其中预应力效应通过降温法模拟,混凝土徐变效应采用随龄期调整的有效模量法计算,材料非线性通过定义材料的弹塑性本构关系和弥散开裂模型实现;在此基础上,根据设计标准图,制作了跨径10m的足尺试件,通过破坏性试验验证全过程分析模型的正确性。结果表明:该模型能够较好地反映试件从生产到破坏的全过程受力特征,通过参数分析提出预应力空心板梁标准图设计建议。在满足强度的前提下,可适当提高混凝土强度、降低配筋指数或预应力比率等方式以提高构件的延性。
Based on the secondary development of common finite element software, the whole process of production, storage, construction, normal use and destruction of hollow slab beams are simulated considering the pre-stress transmission mechanism, concrete creep effect and material nonlinearity . The prestressing effect is simulated by the cooling method and the concrete creep effect is calculated by the effective modulus method adjusted with age. The material nonlinearity is realized by defining the elastoplastic constitutive relation and the diffusion cracking model of the material. On this basis, Standard map, a full-scale specimen with a span of 10 m was produced, and the correctness of the model was verified through destructive tests. The results show that the model can well reflect the stress characteristics of the specimen from the production to the destruction, and propose the design of the standard diagram of the prestressed hollow slab beam through the parameter analysis. Under the premise of meeting the strength, the strength of concrete may be properly raised, and the index of reinforcement or the ratio of prestressing force may be decreased to improve the ductility of the component.