压水堆堆内构件异种材料螺纹联接件在热循环载荷下的疲劳试验分析研究

Research on Fatigue Test and Analyses of Dissimilar-Material Threaded Fasteners of PWR Internals Subjected to Cyclic Thermal Loads

压水堆电厂的反应堆堆内构件中的螺纹联接件与一般联接件不同,在高温、辐照环境中工作,除承受机械载荷外,还承受由于水流以及地震等引起的动态载荷。而在寿命期内反复的冷-热-冷循环,会使异种材料联接件产生交变循环热应力,甚至会使预紧力松弛,因此预紧力合适与否将直接影响联接件联接的可靠性。对通过模拟实际联接结构的联接件进行热循环试验和分析,研究热循环载荷对预紧力和联接结构的影响。

Besides mechanical loads, the threaded fasteners of pressurized water reactor （PWR） internals, working at high temperature and under irradiating circumstance, are also subjected to dynamic loads induced by flow and earthquake, if any, which is different from generic fasteners. The cyclic ther mal loads （ low temperature - high temperature - low temperature, etc. ） during the design life will result in cyclic thermal stress in the dissimilar - material threaded fasteners and loose of preload on the fasteners may occur. So whether the preload is appropriate or not will directly affect the reliability of the fasteners. In this paper, cyclic thermal tests on threaded fasteners simulating the real reactor internal thermal conditions and analyses of the tests are performed. Influences of the cyclic thermal loads on preloads and fastener structures are studied.