Study On Effects Of The Thermal Cycle Load On The Dissimilar Materials Bolted Joints

Bolted joints are the oldest method used for connecting two components together. They are the most commonly used in machines and structures. Recent years, with the development of the industry and improvement of the technology, it puts forward higher request for the design and reliability of the bolted joints because of the modem structure.In this paper, by using experiment and finite element method, bolted joints under the thermal cycle load in the nuclear reactor are studied. The mostly aim of which is to research the force and deformation of bolted joints under the thermal cycle load, and find out the reason of the loosening of bolted joints. The main work could be described as follows:1. By experiment of the thermal cycle load on the four different sizes bolted joints, studied with the length of the bolt and loosening torque and the internal deformation of bolted joints. The subject analyzed clamping force decline. The reason of loosening of bolted joints is find out.2. This paper has established elastic-plastic finite element method calculation mode. Further analyzed the reason of loosening. Find out the rule of the pre-load decline. Based on the data of the field measurements and the calculation's result, this paper has given the appropriate pre-load, and given some beneficial advices on the bolted joints design.3. The compare between the results of compliance coefficient from traditional theory and finite element method presented in this paper. Given advice on the traditional theory calculation, and brought forward easier and more acceptable calculation method which confined to a certain bound.