Study Of Simplified Calculation Method On Stress Intensity Factor Of Surface Crack On Typical Structures In Naval Architecture

T-shaped welded structures, as the most typical part in naval architecture, are considered more about its crack at the welded toe. One normal way to assess the damage degree is numerical calculation, which is really complexes when modeling the crack tip; And another is empirical formulas, such as Irwin’s or Newman’s equation, but always need some parameters hard to measure. So here is a way:If a new kind of approach can be find to calculate the SIF of surface crack without complicated modeling or arguments but only the object’s dimensions which are easiest to obtain, then a very convenient and efficient way will be provided to support the practical engineering, which is really important and will be a great development to the field of modern structural security research.The research take the T-shaped welded plate as the object of the study, try to explore the right way to calculate the SIFs with the maximum crack opening displacement(MCOD), and the whole procedure are detailed researched under tensile loads, bending loads and combined loads. Two core problems are solved during the process and different solving functions under various conditions are obtained, from which we achieve the target to calculate the SIFs through the way of MCOD. This type of way to calculate the SIFs has a high precision which is verified by finite element method.After fitting functions are achieved, range of application of the research results above are expended to most kinds of plate-to-plate welded structure more than T-shaped welded plate through verification of real example, which greatly extended the use of the theory and results in this article. A software application which based on the results, invented to solve the SIFs by input required parameters, is also developed, making a great convenient to the engineering practice, and is expected to further extend.