Study On Equivalent Modulus Of Brazed Aluminum Honeycomb Sandwich Panel

The brazed aluminum honeycomb sandwich panel has better interface bonding properties than the adhesive aluminum honeycomb panel,so the overall mechanical properties are better than the adhesive aluminum honeycomb panel,which has attracted more and more attention in the engineering application field.The basic mechanical parameters of the material are very important for engineering application design,and when designing and evaluating the structure made of it,due to the complexity of the honeycomb structure,it is usually necessary to perform equivalent treatment.At present,there are few studies on the mechanical properties of brazed aluminum honeycomb panels,and the applicability of existing equivalent methods to brazed aluminum honeycomb panels remains to be verified.In this work,the mechanical responses of brazed aluminum honeycomb panels under three static load conditions were obtained through experiments,and several main equivalent modulus test values were obtained,and the theoretical values were also calculated.And finite element models of the brazed aluminum honeycomb panel were established to simulate the mechanical response of the corresponding working conditions,and the response of the test working conditions was compared and verified,and several simulation values of the main equivalent moduli were obtained.Finally,combining the finite element method and comparing three commonly used equivalent models of honeycomb sandwich panels through calculation examples,an equivalent model with better accuracy and applicability was obtained.Experiments were used to verify the equivalent effect of the model.At the same time,the influence of the experimental value,theoretical value and simulation value of the out-of-plane equivalent modulus on the equivalent model was discussed.And provide an effective reference for the design,optimization and use of the material in the engineering field.The main research content and conclusions of this thesis are as follows:(1)Based on flat compression,shear and edgewise compression tests,the load response curve of each working condition and the corresponding deformation stage of the sample were analyzed.The out-of-plane elastic modulus,transverse and longitudinal shear modulus,in-plane elastic modulus,as well as the flat compressive strength,shear strength and edgewise compressive strength of the brazed aluminum honeycomb panel were measured.And combined with the parameters measured in the experiment,the corresponding theoretical formula was used to calculate the theoretical value.(2)Combined with the finite element method,the finite element models of brazed aluminum honeycomb panels under flat pressure,shear and edgewise pressure were established.The comparison test results show that these models can simulate the deformation and response of brazed aluminum honeycomb panels relatively accurately.And the simulation values of out-of-plane elastic modulus,shear modulus and in-plane elastic modulus were obtained.Furthermore,the relevant influencing factors of the equivalent modulus were discussed through simulation.(3)Through the comparison of static and dynamic simulation results of three equivalent models of sandwich panels,equivalent panels and honeycomb panels,the results show that the sandwich model has the highest equivalent accuracy and the best applicability.And through comparison with the transverse three-point bending test,it is showed that the sandwich equivalent model can better simulate the response characteristics of brazed aluminum honeycomb panels.At the same time,the discussion shows that the equivalent effect of using the experimental value of the equivalent modulus outside the core layer is better than using the theoretical value and the simulated value.