Micro-vibration Characteristics Of The Honeycomb Structure In Spacecraft

Micro-vibration on orbit is one of the dominant factors limiting the highly precise spacecraft performance such as pointing accuracy and resolution. Honeycomb sandwich panels are major structural components of spacecraft. So micro-vibration characteristics of the honeycomb structure in spacecraft are important for micro-vibration analysis on the spacecraft. Honeycomb sandwich panels are made up with core, face sheet and adhesive bond. Building accurate equivalent plate model and micro-vibration testing for honeycomb sandwich panels are important contents in the study on the micro-vibration characteristics of the spacecraft honeycomb structure.Firstly, based on deformation mechanism of the core, core was equivalent to continuous orthotropic material, from which equivalent material parameters of the core for uniform and non-uniform wall thickness were derived. According to result of homogenized core, three equivalent plate models were concluded, including Reissner theory model,honeycomb plate theory model and the lower-order shear theory laminated plate model.Secondly, a detailed model of a honeycomb sandwich panel with uniform wall thickness was taken as a standard. The size effect of equivalent plate model was summarized and proved that lower-order shear theory laminated plate model was accurate equivalent plate model for numerical calculation by analyzing the influences of homogenized core, length-thickness ratio and core thickness-side ratio for numerical calculation accuracy of equivalent plate model. For real engineering honeycomb sandwich panels, the influences of non-uniform wall thickness and adhesive bond on the honeycomb sandwich panel couldn’t be ignored. A new simplification method was proposed with accounted for the effect of glue bonds and inbeded intercts. Use the lower-order shear theory laminated plate model of honeycomb sandwich panel that contains embedded parts for modal analyzing, and the error between prediction and test was less than 6% in the first three modal frequencies.At last, an experimental system was designed for testing the micro-vibration characteristics of the honeycomb sandwich panels. The testing experiment of sine sweep proved the accuracy of theoretical models for honeycomb sandwich panels.