针对航天器随机振动设计载荷全频段法往往过于保守的问题,根据随机振动理论,分析了航天器随机振动设计载荷有限频段法的原理；在白噪声基础激励下,比较了有限频段法与位移等效法的设计载荷.结果显示:在单自由度弹簧质量模型下,有限频段法与位移等效法结果基本相同；在二自由度弹簧质量模型及整星模型下,有限频段法要大于位移等效法的设计载荷.以某卫星为例,分析了结构随机振动响应.分析结果表明:航天器不同结构的收敛频率不同,不同方向的位移收敛频率也不同,因此,应根据结构响应收敛频率来确定有限频段法截取频率.%To solve the problem that design load of spacecraft based on full frequency bandwidth is often on the high side, a basic theory of limited frequency bandwidth is analyzed by random vibration theory. Under white noise, the limited frequency bandwidth method is compared with equivalent displacement method. With single-degree-of-freedom, the result of the former method is close to the latter method's, and with two-degree-of-freedom mass-spring model and satellite model, the design load is higher than the latter method's. With the example of a satellite, random vibration response is analyzed. The results show that convergence frequencies of different structures and directions are different, so the upper limited frequency is decided by the convergence frequency of structure response.
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