低频簧片仪是低频段冲击谱测量的主要装置，其结构为一组具有不同固有频率的集中质量悬臂梁。舰艇受到爆炸冲击时，集中质量悬臂梁易发生塑性变形或断裂，直接影响测量结果。为分析集中质量悬臂梁抗冲击能力，利用模态叠加法建立集中质量悬臂梁在冲击载荷作用下理论模型，分析集中质量悬臂梁在冲击载荷作用下动态响应及破坏规律。研究结果表明：集中质量悬臂梁固有频率越高，应力峰值越大，越容易发生塑性变形或断裂；对于集中质量悬臂梁，冲击载荷破坏能力仅与极限谱位移有关，极限谱位移越大，其破坏能力越大；负波延迟对集中质量悬臂梁的破坏能力具有一定影响，可在常规抗冲击设计中通过增大极限谱位移考虑此影响。%Low-frequency reed gage is the main apparatus for low-frequency shock spectrum test. Its structure consists of a series of cantilever beams with lumped-masses and different natural frequencies. When the ship is shocked by the explosion, these cantilever beams will yield plastic deformation or fracture so that the measurement results may include errors. In order to analyze the anti-shock function of the cantilever beams, the modal superposition method was employed to establish a theoretical model for the mass-lumped cantilever beams subjected to the impact load. Their dynamic response to the impact load and the failure law were analyzed. The results show that the higher natural frequency of the cantilever beams can lead to larger peak stress so that the plastic deformation and fracture in the beams may occur more easily. For the mass-lamped cantilever beams, the damage capability of the impact load is only related to the limit spectrum displacement. The damage capability increases with the increasing of the spectrum displacement. Negative wave delay has some influence on the destructive potential for the mass-lumped cantilever beams. This influence can be considered by increasing the limit spectrum displacement in conventional anti-shock design.
展开▼
