Composite Laminates With Centric Hole In Static Strength

Composites were founded in 1960s. As a new kind of material, it has many merits such as high strength-to-weight, high stiffness-to-weight and good designable characteristic. Nowadays, it has been applied widely in aerospace structures. It has lots of pratical engineering significances to investigate on the structures and the damage theory of composites and the research on static strength of composites with a centric hole is the base of these important investigations. In previous studies period, the strength and design criterion of life of mechanically fastened joints in composite laminates with a centric hole, and the method of life anticipated for composites structures with a hole or not, have been studied. This paper is completed on the basis of previous investigations. Further studies of theory and validated test have been carried through, and the analysis methods and analysis technics of composite case structures have been proposed. The numerical result is corresponded with experiments'. The research work of this paper is mainly including following: (1) Using the method of progressive failure, corresponded universal program has been compiled for composites structures with a centric hole in static loads on the basis of large commercial FE software—ANSYS, non-linearity gene-α has been considered as a variable in the program through using direct-iteration method. (2) Bringing forward two methods of static strength failure analysis and progressive failure analysis, two corresponded different currency program have been compiled for simulating the destroyable progresses. (3) Combined criterion is brought forward on the basis of former research. (4) During the period of numerical analysis of composite laminates with a centric hole, three failure criteria, including maximum stress criterion, Hashin criterion and combined criterion, have been compared. It is testified that different criteria and models can influence failure beginning, failure types and the ultimate failure load and the ultimate failure mode. (5) During the period of numerical analysis of composites joints, two different methods of static strength failure analysis and progressive failure analysis have been compared from three aspects—failure law, failure mode and ultimate failure load.