三维光弹性中预应力结构的应力冻结研究

本文提出用三维光弹性应力冻结法模拟分析预应力钢筋混凝土结构中的应力。通过模拟体与实体结构的相似性研究,给出了模型载荷比例系数Cq参数,通过参数合理的选取,有效的解决了应力冻结水平预测这一技术关键;用光弹性应力二次冻结法,将结构预应力和负载应力冻结在同一试件中;应分析精度对模型尺寸的要求,采用了精密浇铸的方法制作模型。此外,还研制了受力清晰明确的加载系统。对这些涉及应力冻结的若干关键问题结合工程实例进行探讨。实验应力分析结果与有限元数值法一致性较好。

An Experimental Study on the Twice-Freezing Stress Method of Photoelasticity for 3-D Stress Fields in Prestressed Reinforced Concrete Structures

In this paper, 3-D stress fields in a prestressed reinforced concrete structure were analyzed using twice-freezing stress method of photoelasticity. The load scale factor, which was given through the study on the similarity between the small-scale model and the tall-scale prototype, was used to predict the stress-freezing level. Using photoelastic stress twice-freezing method the prestress of structure and its stress under loading were frozen in one specimen. According to the accuracy requirements of the analysis with the model dimension, we use the precision casting method to make the models. Besides we developed the loading system which made the load transfer path clearly and simply. These key problems relating to analog simulation were explored by an example in combination with a practical engineering, that some useful results and conclusions are presented. It is shown that the simulated results from experimental stress analyses agree well with the data calculated by finite-element method.