Damage Analysis Of Envelope Material Based On Peridynamic Theory

Peridynamic theory is a new mechanical method emerged in recent years.It uses the model established by non-local theory to solve discontinuities such as crack propagation and crystal phase transformation in macro and micro mechanics fields.Stratospheric aerostatic envelope material is known as coated woven composite material,which is an envelope material made of fiber reinforced structure and coating structure.It has the advantages of high strength,good resistance to helium leakage,good weatherability and so on.The mechanical properties of the flexible skin material are more complicated than that of the rigid composite material,and the damage of the material is not easy to be solved.Therefore,based on the peridynamic method,the damage of envelope material is studied.In this paper,the basic theory,application and research status of peridynamic theory are briefly introduced.Then,the macro peridynamic model of envelope material is built based on the theory of peridynamic theory for composite material.The obtained model can well reflect the tensile properties of woven composite under the woven structure.In order to analyze the damage and rupture of the envelope material,the peridynamic unit cell model of the envelope material was set up from the meso-scale.the characteristics of each fiber in the unit cell space were described,and the numerical simulation of the damage problem were solved by peridynamic theory.The results show that the numerical simulation are consistent with the results obtained by the finite element model and the fracture and crack propagation at the mesoscopic scale of the envelope material are explored.It can provide new ideas and theoretical basis for the study of envelope material damage.