Nonlinear effects of loosely constrained deployable mass on instrument dynamic testing and analysis

Many instruments utilize launch locks (pin-pullers, frangibolts, etc) to restrain deployable assemblies during launch to survive launch vibration and acoustic environments. Non-linear responses have been observed during vibration testing for instruments where the restrained mass represents a significant portion of the total mass. The non-linearity is particularly notable when the mass is loosely constrained and sees large relative displacement compared to the primary structure of the instrument.

诸多航天仪器会采用发射锁定装置（launch locks），涵盖销钉拔出器（pin-pullers）、易碎螺栓（frangibolts）等类型，用于在发射阶段约束可展开组件（deployable assemblies），使其能够承受发射过程中的振动与声学环境载荷。在针对此类仪器的振动测试中，当被约束质量（restrained mass）占仪器总质量的比例较高时，常可观测到非线性响应现象。当该约束质量的约束较为松散，且相对于仪器主体结构（primary structure）出现较大相对位移时，上述非线性特征会尤为显著。