Reliability-based design optimization of space tether considering hybrid uncertainty

Space tether is widely used in the field of global space and its reliability problem increasingly become one of research hotspots in the space field. In order to address such problems as low model versatility, high computational complexity and heavy computation workload, referring to the deployable motorized momentum exchange tether (DMMET) as the engineering background, this paper aims to investigate and study a methodology framework which can deal with hybrid uncertainty factors in design optimization After introducing the structure and application characteristics of DMMET, this paper firstly analyses the performance characteristics and uncertain factors of the deployable mechanism, which is used to establish the neural network surrogate model of the deployable mechanism’s strength and can enable scalability of deployable mechanism. Specifically, it mainly includes the load uncertainty, the uncertainties of system parameters and calculation model. In this paper, we mainly discuss the uncertainty from system parameters, including the various bar size of the developable mechanism (length, width and thickness) and material performance parameters (elastic modulus, density, strength, etc.). Finally, we obtain a more satisfactory optimization results by reliability-based design optimization of a specific developable mechanisms. Numerical examples verify that this method is feasible and has higher solution accuracy, which can offer reference to the DMMET engineering design.