Research On The Ultimate Strength For Scaled Models Based On Energy Drinciple

As experimental research being an important and effective method, it plays a critical role in the realm of ultimate strength. Whether we can precisely predict the ultimate strength of prototype from the results of models depends on the accuracy of the similitude laws between the prototype and the model. As we know there are lots of difficulties in establishing the similitude laws when considering the various nonlinearities presenting in the ultimate strength analysis. Nevertheless if we deal with this problem from a view of energy principles, we can find some new solutions to the problem of establishment of the similitude laws. This paper focuses on the predicting of the ultimate strength of the prototype based on the results of the model experiments by using the energy similarity principle. The results demonstrate the validity of this new method.On the basis of the energy principle, this paper derives the similitude laws for the cantilever beam objected to the concentrated force, the predicting results shows a good agreement with the theoretical results calculated from the closed formulas. Then with the instruction of the principle of stationary potential energy this paper deals with the establishment of the similitude laws for the elastic buckling load of the simply-supported plate under the uniaxial compression. Again the results are good enough compared with the theoretical formulas. Finally, based on the calculating results using the nonlinear FE method of a series of different scaled stiffened plates, a regression analysis is carried out to obtain the relationship between the ultimate loading capacity of the stiffened plates and the ultimate energy which is needed to make the stiffened plates reach its ultimate limit state. A good prediction is obtained with the use of this regression function for the ultimate strength of the stiffened plates.