Selection of Fitting Models of the Moisture Content for Paper Honeycomb Sandwich Panel

2012 ◽  
Vol 200 ◽  
pp. 58-61
Author(s):  
Dong Mei Wang
Keyword(s):  
Experimental Data ◽  
Moisture Content ◽  
Sandwich Panel ◽  
Sandwich Panels ◽  
Influence Of Temperature ◽  
Honeycomb Sandwich ◽  
Best Fitting ◽  
Paper Honeycomb ◽  
Fitting Model ◽  
Selection Of

The influence of temperature and relative humidity on the moisture content of paper honeycomb sandwich panels was studied. The moisture content of paper honeycomb sandwich panels was fitted by three mathematical models. The fitting results were evaluated by experimental data, and the best fitting model and its parameters were determined. The results indicate that in three models, the GAB (Guggenheim, Anderson and De Boer) model is the best suited to predict the moisture content of paper honeycomb sandwich panels in different temperature and humidity conditions.

scholarly journals Comparative study of dynamically equivalent modeling methods for honeycomb sandwich structure: numerical simulations and experiments

2020 ◽  
Vol 11 (2) ◽  
pp. 317-328
Author(s):  
Ning Guo ◽  
Hao Chen ◽  
Zhong Zhang ◽  
Fei Du ◽  
Chao Xu
Keyword(s):  
Numerical Simulations ◽  
Sandwich Panel ◽  
Plate Theory ◽  
Sandwich Panels ◽  
Single Layer ◽  
Design Parameters ◽  
Modeling Methods ◽  
Honeycomb Sandwich ◽  
Equivalent Method ◽  
Honeycomb Sandwich Structure

Abstract. The structure of the lightweight honeycomb sandwich panel is complex. Thus, establishing an equivalent simplified model is indispensable to improve the efficiency of the dynamic analysis of honeycomb sandwich panels. In this paper, three commonly used dynamically equivalent modeling methods for honeycomb sandwich panel are studied: a dynamically equivalent method based on laminated plate theory, a single-layer plate equivalent method based on the theory of Hoff (1948), and an improved equivalent method based on Allen (1969). Using theoretical study, numerical simulations, and experiments, the applicability of these equivalent methods and the effect of design parameters on the dynamic characteristics are studied, and the optimal dynamically equivalent method for honeycomb sandwich panels is obtained.

scholarly journals Mathematical modelling of the thin layer drying of pineapple (Ananas comosus, L.): experiment at village-scale in a greenhouse type solar dryer

2019 ◽  
Vol 20 (2) ◽  
pp. 1-10
Author(s):  
Ignacio López Cerino ◽  
Irineo Lorenzo López Cruz ◽  
Serm Janjai ◽  
Marcus Nagle ◽  
Busarakorn Mahayothee ◽  
...  
Keyword(s):  
Experimental Data ◽  
Moisture Content ◽  
Thin Layer ◽  
Large Scale ◽  
Linear Regression Analysis ◽  
Ananas Comosus ◽  
Solar Dryer ◽  
Thin Layer Drying ◽  
Best Fitting ◽  
Drying Curves

The objectives of this research were two: first to investigate experimentally the behavior of pineappl (Ananas comosus, L.) thin layer drying in a greenhouse-type solar dryer and second to describe the best fitting kinetic and mathematical model taken from literature. A large scale greenhouse dryer designed and installed at Silpakorn University, Nakhon Pathom, Thailand was used to dry slices 1 cm width at temperature range between 25-60 °C with relative humidity between 50-90%. Nine statistical models, either empirical or semi-empirical, were tested in order to validate the experimental data. A non-linear regression analysis conducted by a statistical computer program was applied to evaluate the constants of all the models. The parameter values, root mean square error (RMSE), mean absolute error (MAE) and modelling efficiency (EFF) of the nine models were calculated. Comparison outcomes of two experiments are displayed between the predicted moisture content and the observed pineapple moisture content. Hasibuan and Daud drying model proved to describe the best pineapple solar drying curves. The two experiments were carried out on sunny days, the second experiment on the third day showed cloudiness decreasing the solar radiation. Mathematical models of pineapple drying in a greenhouse dryer have not been found so far in the literature. Drying curves obtained from experiments showed that the constant drying and the falling drying rate periods exist. Nine thin-layer drying models were fitted to two experimental data in order to describe the drying characteristics of pineapple founding that the Hasibuan and Daud model was the best fitting.

scholarly journals High Temperature Mechanical Properties of a Vented Ti-6Al-4V Honeycomb Sandwich Panel

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3008
Author(s):  
Lei Shang ◽  
Ye Wu ◽  
Yuchao Fang ◽  
Yao Li
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Cell Walls ◽  
Sandwich Panel ◽  
Sandwich Panels ◽  
Honeycomb Core ◽  
Compression Performance ◽  
High Temperature Mechanical Properties ◽  
Honeycomb Sandwich ◽  
The Face

For aerospace applications, honeycomb sandwich panels may have small perforations on the cell walls of the honeycomb core to equilibrate the internal core pressure with external gas pressure, which prevent face-sheet/core debonding due to pressure build-up at high temperature. We propose a new form of perforation on the cell walls of honeycomb sandwich panels to reduce the influence of the perforations on the cell walls on the mechanical properties. In this paper, the high temperature mechanical properties of a new vented Ti-6Al-4V honeycomb sandwich panel were investigated. A vented Ti-6AL-4V honeycomb sandwich panel with 35Ti-35Zr-15Cu-15Ni as the filler alloy was manufactured by high-temperature brazing. The element distribution of the brazed joints was examined by means of SEM (scanning electron microscopy) and EDS (energy-dispersive spectroscopy) analyses. Compared to the interaction between the face-sheets and the brazing filler, the diffusion and reaction between the honeycomb core and the brazing filler were stronger. The flatwise compression and flexural mechanical properties of the vented honeycomb sandwich panels were investigated at 20, 160, 300, and 440 °C, respectively. The flatwise compression strength, elastic modulus, and the flexural strength of the vented honeycomb sandwich panels decreased with the increase of temperature. Moreover, the flexural strength of the L-direction sandwich panels was larger than that of the W-direction sandwich panels at the same temperature. More importantly, the vented honeycomb sandwich panels exhibited good compression performance similar to the unvented honeycomb sandwich panels, and the open holes on the cell walls have no negative effect on the compression performance of the honeycomb sandwich panels in these conditions. The damage morphology observed by SEM revealed that the face-sheets and the brazing zone show ductile and brittle fracture behaviors, respectively.

Experiment and Simulation on the Flexural Properties of Fiber-Paper Honeycomb Sandwich Structure Compound Panel

2012 ◽  
Vol 200 ◽  
pp. 80-85
Author(s):  
Xiao Jun Yang ◽  
Qing Shan Lan ◽  
Yu Ning Zhong ◽  
Li Xia Zeng
Keyword(s):  
Sandwich Structure ◽  
Optimization Design ◽  
Sandwich Panel ◽  
Flexural Properties ◽  
Engineering Software ◽  
Equivalent Models ◽  
Bending Load ◽  
Honeycomb Sandwich ◽  
Paper Honeycomb ◽  
Honeycomb Sandwich Structure

Two equivalent models based on sandwich panel theory and equivalent panel theory were discussed in this paper. By analyzing the performance of fiber - paper honeycomb sandwich structure compound panel by bending load, the computational results are in accordance with test and Engineering software ANSYS. Therefore, it shows that the finite element equivalent models are reasonable and practical for the optimization design of fiber - paper honeycomb sandwich composites.

Bending Vibration Analysis of Thick Honeycomb Sandwich Panel

2012 ◽  
Vol 229-231 ◽  
pp. 369-372 ◽  
Author(s):  
Wei Dong Shen ◽  
Sheng Chun Wang ◽  
Jian Li Wang ◽  
Jia Feng Xu ◽  
Si Hong Song
Keyword(s):  
Sandwich Panel ◽  
Differential Operators ◽  
Natural Frequencies ◽  
Equations Of Motion ◽  
Sandwich Panels ◽  
Sheet Thickness ◽  
Single Equation ◽  
Displacement Function ◽  
Bending Vibration ◽  
Honeycomb Sandwich

A simple approach to reduce the governing equations for thick honeycomb sandwich panels to a single equation containing only one displacement function is proposed in this article. The variational equations of motion are derived using Hamilton’s principle and by introducing differential operators. The exact solution of the natural frequencies for rectangular honeycomb sandwich panels with all edges simply-supported is obtained and leading to a satisfied agreement with theoretical results. The influence of the ratio of core thickness to face sheet thickness and aspect ratio on the natural frequencies is studied. The analysis results demonstrate that the presence of inertia of rotation will decrease natural frequencies, and the aspect ration changes not only the value of natural frequencies of the sandwich panel but also the mode order.

scholarly journals Investigation of vibration transmissibility for paper honeycomb sandwich structures with various moisture contents

2019 ◽  
Vol 20 (1) ◽  
pp. 108
Author(s):  
Dong-Mei Wang ◽  
Rui Yang
Keyword(s):  
Moisture Content ◽  
Sandwich Structure ◽  
Sandwich Structures ◽  
Absorption Capacity ◽  
Cell Length ◽  
Vibration Prediction ◽  
Honeycomb Sandwich ◽  
Vibration Transmissibility ◽  
Paper Honeycomb ◽  
Honeycomb Sandwich Structure

Vibration transmissibility is an important factor to characterize the vibration absorption performance of cushioning packaging materials during transportation. Reasonable prediction of vibration transmissibility can guide antivibration design and reduce packaging cost. As a kind of green cushioning material, paper honeycomb sandwich structure is widely used in transport packaging because of its good machinability. But at the same time, it also has strong water absorption capacity. To a great extent, the vibration transmissibility of paper honeycomb sandwich structure may be affected by ambient humidity. In this research, the vibration transmissibility of paper honeycomb sandwich structures with various structure sizes under different humidity was tested by sine frequency sweep experiments. The rule of maximal vibration transmissibility with moisture content, cell length of honeycomb, and thickness of sandwich structure was analyzed. The results show that the maximal vibration transmissibility of paper honeycomb sandwich structure increases with the increase of moisture content, cell length of honeycomb, and thickness of sandwich structure. In order to construct the relationship between maximal vibration transmissibility and various factors, the moisture content was standardized. Finally, the maximal vibration transmissibility evaluation equation of paper honeycomb sandwich structure containing standardized moisture content and size of sandwich structure was obtained, which is of some reference value for vibration prediction of paper honeycomb sandwich structures.

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

2020 ◽  
Vol 29 ◽  
pp. 096369352096312
Author(s):  
Wei Wang ◽  
Haitao Luo ◽  
Jia Fu ◽  
Haochen Wang ◽  
Changshuai Yu ◽  
...  
Keyword(s):  
Sandwich Panel ◽  
Sandwich Panels ◽  
Theory Model ◽  
Solar Array ◽  
Response Analysis ◽  
Frequency Error ◽  
Test Results ◽  
Solar Arrays ◽  
Honeycomb Sandwich ◽  
Honeycomb Panel

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.

Buckling Analysis and Experiment of Fiber-Paper Honeycomb Sandwich Structure Composites

2011 ◽  
Vol 314-316 ◽  
pp. 566-570 ◽  
Author(s):  
Xiao Jun Yang ◽  
Qing Shan Lan ◽  
Yu Ning Zhong
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Composite Structures ◽  
Plate Theory ◽  
Sandwich Panels ◽  
Hexagonal Structure ◽  
Unit Cell ◽  
Honeycomb Sandwich ◽  
Paper Honeycomb ◽  
Element Method

The aim of this paper is to present a finite element method to predict buckling characteristics of paper honeycomb sandwich panels with composite skins under dynamic axial compression via ANSYS/LS-DYNA. First of all, some problems of the conventional method using honeycomb plate theory, sandwich laminboard theory and equivalent panel theory were pointed out. In order to develop an effective predicting method, by assuming appropriate periodic boundary condition on the edges, a simplified finite element model on hexagonal structure of a unit cell for sandwich panels was developed utilizing the 3D finite element method. The effective Young's modulus of the cellular wall was obtained from the result of the test on the honeycomb core. Several useful conclusions are drawn about the axial crushing of honeycomb sandwich composites and unit cell and can be used to guide the design of composite structures. The paper further attempts to explain numerical results are well consistent with the corresponding experimental ones.

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