Research On Structural Optimization Of Micro-Satellite Based On High-Fidelity Model

Nowadays,micro-satellite develops fast due to low-cost,short-cycle and easy-deploy,attaching much importance to rapidity and optimization when designing structure.Developing high-fidelity models is a promising direction for micro-satellite structural design because simulations based on high-fidelity models can validate the feasibility of design scheme immediately and provide reliable data to process of optimization.Therefore,the updating,validation and application in structural design of high-fidelity models are studied in this work.Main contents are summarized as follows:To validate high-fidelity models by comparing responses from simulations and real tests,a new model validation metric,namely combined metric,is proposed.By combing advantages of classical hypothesis testing and area metric,combined metric can not only quantitatively measure the agreement between predictions and physical observations,but also serve as criteria to accept a model with a statistical confidence level.Numerical example shows that the metric is able to make the correct judgment in a higher reliability than method of classical hypothesis testing,demonstrating the effectiveness of the metric.Further,considering uncertainty of modeling and testing,adding testing numbers and reducing testing uncertainty both contribute to the improvement of reliability of making a correct judgment.Since updating models using test data helps improve the predictive ability of models,a new frame of model updating,based on combined metric,is constructed.Kernel of the frame is implementing updating in two levels.If result of combined metric is rejecting a model,suggesting that non-parametric factors(e.g.assumption and simplification)contribute more to the disagreement between predictions and physical observations,the model should be updated in model level.Otherwise,the model should be updated in parameter level,to find exact values for uncertain model parameters minimizing combined metric.The frame is applied in updating process of a FE-model for modal analysis.Simulations and tests show that updated FE-model has a high predictive ability,demonstrating the effectiveness of proposed frame.Structural optimization of micro-satellite based on high-fidelity model is studied.First,models of size optimization of primary structure and topology optimization of supporting pole are set up.Then,optimal problem is solved by integrating commercial software ISIGHT,CATIA and ABAQUS.Results show that under the same constraints,masses of primary structure and supporting pole decrease 33.1% and 26.4% respectively,obtaining an optimal structural design.