形状记忆可展桁架在轨热变形分析研究

Analysis on thermal deformation of deployable shape memory polymer composites truss structure in orbit

借助I-DEAS软件建立了针对形状记忆可展桁架的热-结构耦合分析模型,并试验验证了分析模型的准确性。在此基础上,采用多层隔热复合材料作为热控措施,计算分析有/无热控措施及预紧力大小对桁架温度与热变形的影响。结果表明:包覆多层隔热材料效果明显,可将桁架在轨周期内的温度差减小85%,位移差减小80%,有利于对可展桁架进行温控,实现展开与收拢,减小运行期间振动的影响;桁架变形大小由预紧力和热应力共同决定,随着预紧力增大,桁架位移差逐渐减小。

Athermo-structure analysis model of shape memory deployable truss was established using I-DEAS,and verified by a vacuum experiment.The multi-layer insulation(MLI)material was used for thermal control.The temperature and thermal deformation of the truss structure was calculated with/without thermal control under different preload.The simulation results indicate that MLI can significantly reduce the difference of temperature and displacement of the truss structure in one orbital cycle that the temperature difference can be reduced by 85%and the displacement difference can be reduced by 80%.That is helpful for the truss to deploy and fold under temperature control and to reduce the vibration.The displacement of the truss structure is influenced by both preload and thermal load.With the increase of preload,the displacement difference of truss decreases gradually,but the amplitude is limited.