Research On Composite Foam Sandwich Panel Pre-embedded Bolt Connection Pull-off Damage

Composite foam sandwich panels are made up with fiber reinforced composite material panels and filled with foam. Composite foam sandwich panels have many unique properties such as lightweight, heat insulation, noise absorption, vibration absorption and energy absorption. It has been widely used in high-tech fields such as aerospace, shipbuilding,manufacture of high-speed trains and wind turbine blades. Composite foam sandwich panel is composited of fiber-reinforced composite panels and lightweight foam core components. This material can obviously lighten the weight of the structure. Meanwhile, using this material can effectively decrease the vibration harm and the noise damage. Composite foam sandwich panel has been successfully used in aircraft wings, other aircraft parts, ship cabin floors and many other structural components.Based on the tensile tests and numerical analysis of composite foam sandwich panels as well as pull-off tests and numerical analysis of the composite foam sandwich panels which embedded bolted joints, the paper examine the damage of the bolt connection joints in both fiber reinforced composite material panels and composite foam sandwich panels. The main contents are as follows:1. Different kinds of fiber reinforced composite material panels are prepared by VARI technique. Study on some key points in VARI technological process and then give some guidelines on the curing molding preparation of composite foam sandwich panels.2. Tensile experiments of composite foam sandwich panels are carried out to study the tensile strength and the tension stiffness of different kinds of fiber reinforced composite material panels. And examine the influence of the strain rate to the elastic modulus and tensile strength in different kinds of fiber reinforced composite material panels. And then observe the failure mode of these composite materials which under tensile load.3. Numerical simulations on tensile failure of glass fiber reinforced composite panels are made to study the progressive damage of the matrix and fibers. What is more, numerical simulations on tensile failure of glass fiber reinforced composites to analyze the impact of the aperture to the injury of the composite plate.4. Pull-off tests are made on composite foam sandwich panels which embedded bolted joints to study the connection failure modes and strength of the joints. Numerical simulations are made to analysis the bubble destruction and the changing process of layer damage. And finally give some suggestion on the parametric of the bolt joint.