The Study Of Virtual Test System For Fatigue Strength

Fatigue failure was one of the major failure modes. As there were many inherent defects in the traditional method of fatigue test, such as long period, high cost, difficulty of control in test condition etc, so the anti-fatigue joints were mainly studied by theoretical calculation and previous experience. In recent years, the appearance of virtual test technique broke through the limitation of traditional test, and provided an effective way to test and analyze the equipments or systems which have complex structure, high difficulty and cost in testing course. In the paper, virtual test technique for fatigue life of ship structure was studied, and the main works were as follows:1) Ship fatigue test was introduced, fatigue evaluation method based on S-N curve which take into account the mean stress was studied. And the calculation process of fatigue damage for ship structures under the random wave load was given.2) The basic methods of the dynamic response analysis was introduced,and also the calculation of dynamic response of ship structures under time-domain wave loads and its application in a virtual test system were studied. The fatigue virtual test during the time domain is initially achieved.3) The connotation and key technique of virtual test technique were described. According to the method of real ship test, the basic idea and realization scheme of virtual test technique for fatigue life of ship structure were discussed in the paper.4) Base on the theoretical study above and the frequency domain virtual test system basis, according to the technical requirements of the program, the dynamic analysis and virtual testing were combined to further improve a virtual test system of fatigue strength for ship structures by using C, VC + + computer language.5) Through the virtual test of a real ship for example, the results of its fatigue damage were given.