Progressive Damage Analysis Of Connection Structure On Composite Superstructure

Composites have shown superior performances in improving the stealth of ships.Its uses in ships especially the superstructure has attracted highly attention of many countries,and some of them have developed a detailed research plan.However,it is the composite joint which is an important factor in determining the strength of the composites structure.There are many forms of composite joints,but the overall developing trend towards no fasteners.However,mechanical or mixed connection is mainly used in engineering at the present stage due to the restriction of process and adhesive materials.In this paper,numerical and experimental investigations are both performed for the composite connection structure,while a method for estimating the squeezing strength of the mechanical connection in marine engineering applications is proposed.Also,the form of the composite connection structure between the superstructure and deck is designed and calculated.The detail information is as follows.The progressive failure of composite laminates is studied,and the failure criteria of the failure strength of the composite material as well as the composite stiffness reduction model are given.The penalty function method is defined for the contact problems of the connecting structures,and the available progressive failure computing model of the joints is given.The tensile test of the carbon fiber laminates with a double-bolt connection structure of single shear is performed.Compared with the traditional method of implicit operations,the computational efficiency of quasi-static explicit operator analysis is five times faster.It is shown that the numerical and experimental results are fit well.The research of double shear connecting structure between the marine FRP and steel plate is investigated based on the numerical method.The impact of the connection structure in the compression strength is also studied with consideration of width of plate,pore diameter,load direction and the end-to-end length respectively,and the formula to estimate the compression strength of the double shear composite connection structure is achieved,which can be adapted to the engineering applications.The longitudinal and transverse forces and bending moments of the connection between the superstructure and steel deck are calculated though the analysis of the overall composite superstructure.Meanwhile,the geometric parameters of the FRP-steel joint is designed,and its strength meets the requirements.