Risk Assessment And Equipment Layout Design For Spacecraft Considering Space Debris' Influence

With the gradual deterioration of the space environment,space debris shielding has become an important part of spacecraft design phase.The layout optimization of spacecraft can be seen as a potentially cost-effective method to the mainstream approach of adding shielding mass.In this dissertation,impact risk assessment for spacecraft is carried out from the perspective of space debris shielding,and then carry on the comprehensive evaluation and optimization of the design scheme considering space utilization,static non-equilibrium and impact risk.The main achievements researched in this dissertation are summarized as follows:Established a space debris impact risk assessment model.Developed a finite element model of the spacecraft,which was achieved by pre-processing software Patran,to digitally represent the geometry of the spacecraft.Using the method of eliminating hidden surface in Computer Graphics,an algorithm of processing shadowing effect was designed,which determined whether a finite element in the debris flux direction was shadowed by other parts.Established a risk assessment model and the model was calibrated by three standard cases of IADC specified.The results showed that the computing precision of the risk assessment model is very good with precisions of similar software in different countries.Established an equipment layout optimization model considering the impact risk,and proposed the optimization method of spacecraft overall layout design.Established a spacecraft layout optimization model based on the two-dimensional layout optimization of a satellite cabin.The impact risk index for spacecraft in orbit was established on the basis of the space debris risk assessment model,and then the layout of the spacecraft was optimizated considering space utilization,static non-equilibrium and impact risk.Respectively,using single-objective and multi-objective method to solve the layout optimization model.Proposed a decision-making strategy of layout scheme based on multi-index comprehensive evaluation method.In order to significantly reduce the burden on decision makers,a method called Smart Pareto Filter was designed to obtain the most compact form of Pareto set by comparing the whole Pareto front.Studied the comprehensive evaluation and decision-making process of layout scheme.Making focus on the study of index normalization,determination of objective weight and index synthesis.Established the multi-objective decision-making model of the layout scheme,and solved the problem of sorting and selecting of layout scheme under the condition of limited number.The achievements obtained in the current dissertation has two important significance.On the one hand,is to support the space debris impact risk assessment of spacecraft.On the other hand,is to serve as powerful support to the improvement of spacecraft overall layout design.