Numerical analysis of the behavior of a three-layer honeycomb panel with interlayer defects under action of dynamic load

The aim of the work is to study the effect of interlayer defects of the bundle type on the behavior of a rectangular flat three-layer panel with a honeycomb filler under the influence of a dynamic impact load. Methods. The problem was solved numerically using the finite element method in the Simcenter Femap and LS-DYNA (Livermore Software Technology Corp.) software complexes. For this purpose, a geometric model of a panel with a honeycomb placeholder was developed. Based on the geometric model, a finite element model of the panel was created using three-dimensional finite elements. In the software complexes, the finite element model was calculated under specified boundary conditions, then the stress fields and fracture indices in the panel were determined, taking into account and without taking into account damage. Results. The stress fields in the panel are numerically determined with and without defects. The fields of the failure indices of the panel layers under the impact load are investigated using various failure criteria (Puck, Hashin, LaRC03 (Langley Research Center)) of polymer composite materials. The analysis of the influence of a defect on the behavior of a honeycomb panel under the impact load is carried out.

Temperature Effect on the Modal Frequencies of Aluminum Honeycomb Plate

The aim of this paper is to perform a study on how the elevated temperature and gradient of temperature affect the natural frequencies of aluminum honeycomb plate. This study is carried out for temperature range between 200K and 800K, and gradient temperature (ΔT) across the thickness direction of the plate between [0-500K]. Different honeycomb plate geometries have been selected for the analysis, by changing the core thickness, skins thickness and cell size. The obtained results show that the effect of the temperature is noticeable. At temperature 800K, the natural frequencies decrease by 16.1% in comparison to their values at ambient temperature (300K). That means, high temperature makes the material suffers from weak rigidity, which furthermore contribute to high decrease of all the frequencies. In addition, investigations carried out in this work relate to the modal analysis of the honeycomb plate, under various gradients of temperature across the core of the plate. The obtained results show that the gradient of temperature has an effect on the modes of vibration of the honeycomb plate. This effect becomes significant when the gradient of temperature is very high. At ΔT equal 500K, the natural vibration modes decrease by 9.5% in comparison to the case where no gradient of temperature (ΔT = 0K) is applied between the two faces of the plate. Keywords: honeycomb panel; aluminum; natural frequency; finite element method; temperature.

Determination of the Load Carrying Capacity of Honeycomb Panels at Fixing Points under an External Load

In this article, the object of study is a three–layer honeycomb panel with fixing elements (FE), which are used for transporting the panel, and fixing it to the spacecraft. The goal of the work is to determine experimentally the load carrying capacity of the fixing elements under various types of loading, to determine the load carrying capacity of the honeycomb panel of the spacecraft at fixing points and further comparison of the experimental results with the finite element method results calculated by MSC.Patran / Nastran. A method for conducting static tests of fixing elements of a spacecraft honeycomb panel under an external load is described, a description of computer technology of a finite–element solution to the problem of static strength of a honeycomb panel structure in the MSC.Patran environment is presented, and a finite–element model of a honeycomb panel is designed. An assessment of the strength of a three–layer structure at fixing points was carried out, followed by validation of the finite–element model of a honeycomb panel. On the basis of the validated model, the evaluation of the strength of the honeycomb structure was carried out; based on results obtained, the conclusion has been made about the convergence of the results by the finite element method with the results obtained during the experiment.

Test Research on Progressive Collapse Resistance of Aluminium Alloy Honeycomb Panel-rod Composite Latticed Shell

In order to study the progressive collapse resistance of the panel-rod composite latticed shell, a static test was performed on two latticed shells with the same size, one of which was removed a key member. The results of experiments and numerical simulations show that the composite reticulated shells were damaged due to the fracture of some members and the shearing of some rivets. Compared with the complete latticed shell, the bearing capacity of the latticed shell which was removed a key member did not decrease too much, but its displacement of the joints increased significantly. The phenomenon indicated that the removal of the key member had a certain effect on the progressive collapse resistance of the composite latticed shell. The key members of the composite latticed shell must be locally strengthened.

Comparative application analysis and test verification on equivalent modeling theories of honeycomb sandwich panels for satellite solar arrays

Due to the difficulty of direct finite-element modeling for honeycomb sandwich panels, it is more common to apply equivalent modeling theories. It is necessary to compare their equivalent precision and then to determine the method with the best equivalent performance so as to prepare for the application in satellite solar arrays. The first 10 natural frequencies are obtained by analyzing the dynamic characteristics of sandwich panel theory model, honeycomb panel theory model, and equivalent panel theory model. The equivalent errors of different equivalent methods are obtained by comparison with the analysis results of real honeycomb panel model. Then, the sandwich panel theory and the Hoff theory with high precision are used to simulate the solar array panel. The two methods are further verified and compared by simulation and experiment. Finally, the sandwich panel theory with the highest accuracy is selected to simulate the vibration response of the solar array panel based on the above work. By comparing the frequency response analysis results with the test results, it is found that the maximum acceleration response error is within 7%, and the corresponding frequency error of the main direction is within 3%. The comparison between random analysis results and test results shows that the root mean square response errors of acceleration in three directions are within 13.7%. It is proved that the sandwich panel theory has high accuracy in the honeycomb structure. Based on the background of a specific space project, this study innovatively applies the test results to compare several typical equivalent theories of honeycomb sandwich panels so as to get a theory with the highest equivalent precision. The final conclusion has been applied to the design of related space products and proved to be feasible. This provides important reference and basis for the structural design of the satellite.