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A structure-level smart deployable truss (SDT) was further studied for on-orbit verification on the SJ18 Geostationary Satellite in this work on the basis of a material-level validation of a shape-memory polymer composite (SMPC) sheet on the SJ17 Geostationary Satellite in 2016. In the SDT, a shape-memory alloy (SMA) mechanism was used to replace traditional pyrotechnic devices for locking and releasing, and SMPC actuation laminates were employed to replace traditional motor or spring driving mechanisms. With a strict parameter constrain of mass, size, and stiffness, the current form of the SDT flight hardware was finally obtained through several cycles of optimization design. Its systematical ground-based experiments were conducted, and the overall structural and functional performance met the demands of the aerospace standards of China. The locking force and expansion breaking force of the SMA releasing mechanism were ∼2000 and ∼10,000  N, ensuring the locking and unlocking reliability for the movable parts with mass 5 kg. The actuation force of all SMPC laminates decreased from ∼30  N (0°) to ∼12  N (165°) with a recovery duration of ∼150  s, which was strong enough for SDT deployment in space. The shape-memory materials show great prospects for smart deployable structures in space. [ABSTRACT FROM AUTHOR]

Based on our previous successful material-level verification of a shape-memory polymer composite (SMPC) on the SJ-17 geostationary satellite on a geostationary orbit since November 2016, a structure-level smart solar array was developed in this study to further verify its overall performance on the SJ-18 geostationary satellite. The two-panel smart solar array based on shape-memory materials was designed and experimentally evaluated. The smart solar array consisted of two deployable solar panels, which were locked by one shape-memory alloy and two SMPC releasing mechanisms, and could be released by low shocking through electrical heating. The smart solar array was actuated and deployed using two groups of SMPC hinges. A series of tests was conducted to evaluate the main performance of the smart solar array. The tests included structural dynamics (folded state: sinusoidal sweep vibration, shocking, acceleration, and noise; and deployed state: mode, sinusoidal sweep vibration, and flexibility), thermal design, locking and releasing, and deployment. This smart solar array satisfied the design requirements, including the fundamental natural frequency in a folded state at 80 Hz, maximum the locking force at 2000 N. Based on the structure-level systematical evaluation, the SMPC shows prospect to be used in next-generation superlarge deployment structures. [ABSTRACT FROM AUTHOR]

To remove the calculations of inverse and/or exponential of large-scale matrix in the precise time integration (PTI) method for transient response analysis of structures, new PTI methods equipped with the restarted Krylov subspace method and real Leja points interpolation method to calculate exp(A)b are presented in this paper. In both kinds of methods, only the multiplications of sparse matrix and vectors are involved. The theories and implementations of the improved PTI methods are introduced. The transient responses of a cantilever beam and an aeroengine bladed disk are used as numerical examples to validate the accuracy and efficiency of the proposed methods. The effects of tunable parameters of both kinds of algorithms on the numerical efficiency are also discussed. It has been demonstrated that the improved PTI methods are accurate and insensitive to integration step length and, more importantly, are highly efficient for large-scale structures subjected to high-frequency excitations, which greatly extend the applicability of PTI methods. [ABSTRACT FROM AUTHOR]