Buckling And Post-buckling Analysis Of Plate With Multiple Cracks

Thin plate is one of the main structure forms of engineering, and the stability issue has been ofhighly concern. With the development of engineering technology, it is found that metal thin plate willnot lose efficacy due to buckling, but still has a certain carrying capacity, this phenomenon isso-called post-buckling. Multiple cracks widely exist in aircrafts, pressure vessels, piping and otherstructures, and multi-part damage has become one of the main damage forms of engineering structures.There have been previous studies on the buckling issue of thin plate containing single crack. However,researches on the buckling and post-buckling of plate with multiple cracks are rarely reported. Inorder to improve the buckling and post-buckling theory and provide the foundation for theestablishment of multiple cracks damage tolerance design, carrying out the buckling andpost-buckling research of plate with multiple cracks is of great significance.This thesis is to study the above issue by both experiment and simulation methods. In theexperiment section, test was accomplished by the self-designed fixtures. To investigate the bucklingload of plate with multiple cracks, the effects of cracks number, length, position, inclined angle, platethickness and boundary conditions were studied. In the meantime, the post-buckling phenomenon wasobserved. In the simulation section, modeling and calculation were completed based on the finiteelement software ABAQUS. Firstly, by comparing the calculated values with the theoretical values oftypical examples, the validity of the calculation method was verified. Then the buckling loads of thetest models were calculated and the results were consistent with the experimental laws. Besides, theresearch of some else factors on the buckling load were carried out by simulation. Based on the linearbuckling analysis, the post-buckling process was simulated. Through the load-displacement curvesand the load-deflection curves, the relationship between the initial buckling load and ultimate loadwas summed up. Lastly, the importance of boundary conditions on the carrying capacity of thestructure was proved. The result indicates that adding constraint on the non-load side can significantlyimprove the ultimate bearing capacity of the post-buckling stage.