Design Optimization of Honeycomb Core Sandwich Panels for Maximum Sound Transmission Loss

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Rohan Galgalikar ◽  
Lonny L. Thompson
Keyword(s):  
Cell Wall ◽  
Sandwich Panel ◽  
Transmission Loss ◽  
Sound Transmission ◽  
Geometric Parameters ◽  
Constant Mass ◽  
Honeycomb Core ◽  
Wall Angle ◽  
Unit Cells ◽  
Interior Cell

This study focuses on sound transmission frequency response through honeycomb core sandwich panels with in-plane orientation. Specifically, an optimization technique has been presented to determine the honeycomb unit cell geometric parameters that maximize the sound transmission loss (STL) through a sandwich panel, while maintaining constraints of constant mass and overall dimensions of panel length and height. The vibration characteristics and STL response of a sandwich panel are parameterized in terms of four honeycomb unit cell independent geometric parameters; two side lengths, cell wall thickness, and interior cell wall angle. With constraints of constant mass and overall dimensions, relationships are determined such that the number of independent variables needed to define the honeycomb cell and panel geometry is reduced to three; the integer number of unit cells in the longitudinal direction of the core, number of unit cells in the height direction, and interior cell wall angle. The optimization procedure is implemented by linking a structural acoustic finite-element (FE) model of the panel, with modefrontier, a general purpose optimization software. Optimum designs are obtained in representative frequency ranges within the resonance region of the STL response. Optimized honeycomb geometric solutions show at least 20% increase in STL response compared to standard hexagonal honeycomb core panels. It is found that the STL response is not only affected by the cell wall angle, but strongly depends also on the number of unit cells in the horizontal and vertical direction.

Sound transmission loss characteristics of sandwich aircraft panels: Influence of nature of core

2016 ◽  
Vol 19 (1) ◽  
pp. 26-48 ◽  
Author(s):  
MP Arunkumar ◽  
Jeyaraj Pitchaimani ◽  
KV Gangadharan ◽  
MC Lenin Babu
Keyword(s):  
Sandwich Panel ◽  
Transmission Loss ◽  
Sheet Material ◽  
Low Frequency ◽  
Sandwich Panels ◽  
Sound Transmission ◽  
Sound Transmission Loss ◽  
Honeycomb Core ◽  
Transmission Characteristics ◽  
The Impact

Sandwich panel which has a design involving acoustic comfort is always denser and larger in size than the design involving mechanical strength. The respective short come can be solved by exploring the impact of core geometry on sound transmission characteristics of sandwich panels. In this aspect, the present work focuses on the study of influence of core geometry on sound transmission characteristics of sandwich panels which are commonly used as aircraft structures. Numerical investigation has been carried out based on a 2D model with equivalent elastic properties. The present study has found that, for a honeycomb core sandwich panel in due consideration to space constraint, better sound transmission characteristics can be achieved with lower core height. It is observed that, for a honeycomb core sandwich panel, one can select cell size as the parameter to reduce the weight with out affecting the sound transmission loss. Triangular core sandwich panel can be used for low frequency application due to its increased transmission loss. In foam core sandwich panel, it is noticed that the effect of face sheet material on sound transmission loss is significant and this can be controlled by varying the density of foam.

Prediction of Sound Transmission Loss for Finite Sandwich Panels Based on a Test Procedure on Beam Elements

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
Zhongchang Qian ◽  
Daoqing Chang ◽  
Bilong Liu ◽  
Ke Liu
Keyword(s):  
Sandwich Panel ◽  
Transmission Loss ◽  
Test Procedure ◽  
Sandwich Panels ◽  
Sound Transmission ◽  
Expansion Method ◽  
Bending Stiffness ◽  
Sound Transmission Loss ◽  
Modal Expansion ◽  
Beam Elements

An approach on the prediction of sound transmission loss for a finite sandwich panel with honeycomb core is described in the paper. The sandwich panel is treated as orthotropic and the apparent bending stiffness in two principal directions is estimated by means of simple tests on beam elements cut from the sandwich panel. Utilizing orthotropic panel theory, together with the obtained bending stiffness in two directions, the sound transmission loss of simply-supported sandwich panel is predicted by the modal expansion method. Simulation results indicated that dimension, orthotropy, and loss factor may play important roles on sound transmission loss of sandwich panel. The predicted transmission loss is compared with measured data and the agreement is reasonable. This approach may provide an efficient tool to predict the sound transmission loss of finite sandwich panels.

Sound transmission loss behavior of sandwich panel with different truss cores under external mean airflow

2019 ◽  
Vol 86 ◽  
pp. 714-723 ◽  
Author(s):  
Tao Fu ◽  
Zhaobo Chen ◽  
Hongying Yu ◽  
Xuezhi Zhu ◽  
Yanzheng Zhao
Keyword(s):  
Sandwich Panel ◽  
Transmission Loss ◽  
Sound Transmission ◽  
Sound Transmission Loss

scholarly journals Analytical Study on the Rate of Sound Transmission Loss in Single Row Honeycomb Sandwich Panel Using a Numerical Method

2020 ◽  
Vol 54 (2) ◽  
pp. 127-137
Author(s):  
Rohollah Fallah Madvari ◽  
Mohammad Reza Monazzam ◽  
Mohsen Niknam Sharak and Mohsen Mosa Farkhani
Keyword(s):  
Numerical Method ◽  
Analytical Study ◽  
Sandwich Panel ◽  
Transmission Loss ◽  
Sound Transmission ◽  
Sound Transmission Loss ◽  
Single Row ◽  
Honeycomb Sandwich

Evaluation of elastic constants of A3003 honeycomb core with varying hexagonal cell geometries through finite element approach

2013 ◽  
Vol 228 (10) ◽  
pp. 1689-1700 ◽  
Author(s):  
S Rajkumar ◽  
D Ravindran ◽  
Ramesh S Sharma ◽  
VP Raghupathy
Keyword(s):  
Finite Element ◽  
Cell Wall ◽  
Elastic Constants ◽  
Wall Thickness ◽  
Sandwich Panel ◽  
Load Transfer ◽  
Cell Wall Thickness ◽  
Honeycomb Core ◽  
Finite Element Approach ◽  
Element Approach

Aluminum honeycomb core is one of the most sought after material for the sandwich panel for light weight applications. While the aluminum face sheet is isotropic, the honeycomb core assumes orthotropic characteristics due to its configuration and strenuous load transfer paths. It is now well established that stiffness, dynamic, and low velocity impact response of the honeycomb core sandwich panel are critically dependent on the elastic constants of the core. An attempt is made to determine the elastic constants of orthotropic core through finite element approach simulating the load transfer and fixity boundary conditions likely to be prevalent in the unit cell of the honeycomb core. The cell wall thickness and the cell shape dictated by plastic bending limitations have also been simulated to determine their influence on the elastic constants. Further, the cell wall thickness and the bend radius have been varied and their influence on orthotropic elastic constants has been determined. The results of the study have been compared with analytical solutions proposed by researchers. The finite element procedure evolved is a simple, efficient, and quick solution methodology to accurately predict elastic constants of honeycomb core depicting the exact cell size and shape.

scholarly journals Effect of Cell Wall Thickness on Local Compression Fatigue Property of Honeycomb Core Sandwich Panel

2012 ◽  
Vol 78 (787) ◽  
pp. 299-310 ◽  
Author(s):  
Yukiyoshi KOBAYASHI ◽  
Toshihisa OHTSUKA ◽  
Yoshinao KISHIMOTO ◽  
Syougo INUMA ◽  
Yuuki OHTSU
Keyword(s):  
Cell Wall ◽  
Wall Thickness ◽  
Sandwich Panel ◽  
Fatigue Property ◽  
Cell Wall Thickness ◽  
Honeycomb Core

scholarly journals Sound Insulation of Corrugated-Core Sandwich Panels: Modeling, Optimization and Experiment

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7785
Author(s):  
Longlong Ren ◽  
Haosen Yang ◽  
Lei Liu ◽  
Chuanlong Zhai ◽  
Yuepeng Song
Keyword(s):  
High Frequency ◽  
Sandwich Panel ◽  
Transmission Loss ◽  
Finite Size ◽  
Sandwich Panels ◽  
Sound Transmission ◽  
Coefficient Of Determination ◽  
Design Parameters ◽  
Sound Insulation ◽  
Vast Number

With the extension of the applications of sandwich panels with corrugated core, sound insulation performance has been a great concern for acoustic comfort design in many industrial fields. This paper presents a numerical and experimental study on the vibro-acoustic optimization of a finite size sandwich panel with corrugated core for maximizing the sound transmission loss. The numerical model is established by using the wave-based method, which shows a great improvement in the computational efficiency comparing to the finite element method. Constrained by the fundamental frequency and total mass, the optimization is performed by using a genetic algorithm in three different frequency bands. According to the optimization results, the frequency averaged sound transmission of the optimized models in the low, middle, and high-frequency ranges has increased, respectively, by 7.6 dB, 7.9 dB, and 11.7 dB compared to the baseline model. Benefiting from the vast number of the evolution samples, the correlation between the structural design parameters and the sound transmission characteristics is analyzed by introducing the coefficient of determination, which gives the variation of the importance of each design parameter in different frequency ranges. Finally, for validation purposes, a sound insulation test is conducted to validate the optimization results in the high-frequency range, which proves the feasibility of the optimization method in the practical engineering design of the sandwich panel.

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