不用离心力模拟重力的外载与自重共同作用下的试验原理及其应用

大型工程结构在强度设计时,考虑工作应力的同时还要计及自重应力,针对外载与自重共同作用下,现在的用离心力场模拟重力场获得自重应力的试验投资耗费大,技术复杂且难度大和不安全等缺点,本文按照结构相似的模型理论,导出这个问题具体的相似律和试验原理及方法,进行了典型实验验证,指出仅用一个模型试验,即不用离心力场模拟重力场的试验,就可以获得上述两种载荷共同作用下的应力分析结果,根据大型复杂空间工程结构模型自重影响不可忽视的特点,还用本文方法进行了桥梁工程结构的三维光弹性应力分析,并与有限元计算作了比较,二者符合良好。

EXPERIMENTAL PRINCIPLE AND ITS APPLICATION OF MODEL UNDER ITS OWN WEIGHT WITH EXTERNAL LOADS WITHOUT GRAVITATIONAL MODELING

In the case of strength design of large scaled engineering structures, it is often necessary to consider the effect of the weight of the structure. In order to obtain the model stress under its own weight and external loads, the gravitational loading experiment must be performed. However, it is too expensive in investment, complex in experimental techniques, difficult and dangerous in performance. In this paper to overcome these drawbacks, the similarity relations together with a new method and its principle of experiment have been developed based on the model theory of structural similarity. According to this principle, the total stress can be obtained as a sum of the stresses due to weight and external loading, which based on only one model experiment without any gravitational loading experiment. In consideration of the effect in large scaled and complex engineering structural model weight can not be ignored, by means of the new method in this paper, the 3 D photoelasticity analysis results of a bridge have been obtained, which well agree with the results of finite element method analysis.