Structure Design And Experience Research On Frangible Composite Cover

This paper introduces a new structure design and experience research on frangible compositecover. This structure consists of many sub-components inlaid with each other and sealed layers whichconnected these sub-components. Based on the theory of topological interlocking, the strength andstiffness requirements can be satisfied under normal pressure condition, but when the pressure reachesthe particular value, the top part of the cover is blown. Hence, the rest parts are separated inpredetermined trajectory under the subsequent impact load which achieves the designed goal ofdirectional damage.A series of tests on base material of this structure are planned to verify the design idea based onlinear elasticity theory and finite element method. According to the results of these tests, the concreteparameters of this structure are accomplished which is validated by FEM numerical simulation andtheoretical calculation.Besides，a solution of failure control under given load is proposed by controlling the adhesiverange of the adhesively bonded joint in circumferential direction. During this solution，the finiteelement method is used to simulate the stress distribution in different lengths of the adhesive layer andthen calculate the required length of the adhesive layer. Finally, the influence of the parameter in theweak structure is discussed.Then, the research on sides of the cover is studied. By FEM software, a damage process ofadhered sides is simulated. And by placing hinges between sides and flange, each destructed part ofsides under impact load separate in predetermined trajectory. Finally, the magnitude of the impact loadis predicted.In accordance with the design scheme requirements, a test sample is made to finish a series oftests. Through these tests, the design idea is verified to be correct. And the results matched with theFEM solution well.