Experimental research on ultimate strength behaviors of cracked plates under uniaxial cyclic load

This study aims to investigate the ultimate strength behaviors of cracked hull plates under uniaxial cyclic load using an experimental method. Test results of the elastic-plastic property, accumulative plastic damage, crack propagation rate and bearing capacity were obtained by conducting a series of model experiments on plate specimens. The affecting regularity of five load patterns on the accumulative plastic deformation, fatigue crack propagation and bearing capacity was mainly discussed. While the load patterns were designed to approximately simulate the possible wave loads hull plates may bear in actual sea conditions. The effects of accumulative plastic damage and fatigue crack damage on the ultimate strength were considered simultaneously. An equivalent numerical simulation method was developed to simplify the large number of cycles. The accuracy and rationality of the numerical simulation method were also verified. A few new insights were revealed for hull thick plates, which will be some fundamental foresights for the authors’ further experimental study on cracked stiffened plates. •Until now few ultimate strength experiments are investigated on hull structures considering accumulative plastic damage and fatigue crack damage simultaneously, while the present paper has conducted a series of tests on this topic.•Diverse cyclic load conditions are designed to approximately simulate the possible wave loads hull plates may bear in actual sea conditions.•An equivalent numerical simulation method is developed and verified by accumulated strain calculation at the crack tip to simplify the numerical simulation of large number of cycles.•The accuracy of simulation computing technologies such as restart technique and dead-live element method utilized by the author is verified by comparisons of the buckling deformation, crack propagation, load paths and ultimate strength obtained by the test and finite element methods.•Some common conclusions are drawn and verified from the hull thick plate tests in present study as the hull thin plate studied in the author's previous researches. While new insights are also revealed only for hull thick plate, which offer more comprehensive understanding of ultimate strength behaviors of hull plates under cyclic wave loads.