scholarly journals Strength Analysis of an Aircraft Sandwich Structure with a Honeycomb Core: Theoretical and Experimental Approaches

2021 ◽  
Vol 39 (1A) ◽  
pp. 153-166
Author(s):  
Sadiq E. Sadiq ◽  
Muhsin J. Jweeg ◽  
Sadeq H. Bakhy
Keyword(s):  
Cell Wall ◽  
Energy Absorption ◽  
Sandwich Structure ◽  
Peak Load ◽  
Maximum Energy ◽  
Maximum Deflection ◽  
Honeycomb Core ◽  
Three Point Bending ◽  
Bending Load ◽  
Core Height

In this paper, the strength of  aircraft sandwich structure with honeycomb core under bending load was evaluated theoretically and experimentally based on failure mode maps. A failure mode map for the loading under three-point bending was constructed theoretically to specify the failure modes and corresponding load. Three point bending test for aluminum honeycomb sandwich beam has been achieved to measure the peak load and maximum deflection. The obtained results elucidated a good agreement between the theoretical solutions and experimental tests, where the error ratio was not exceeded 12%. The core height, the cell size and the cell wall thickness were selected to explore the effect of honeycomb parameters on the strength of sandwich structure. In order to obtain the optimum solution of peak load and maximum deflection and energy absorption, Response Surface Methodology (RSM) was used. Results showed that the maximum bending load, minimum deflection, and maximum energy absorption were found at 25 mm core height, 10 mm size cell and 1 mm  cell wall thickness. The optimal value of maximum bending load, minimum deflection and maximum energy absorption were 1975.3415 N, 1.0402 mm and 1.0229 J respectively.

scholarly journals Experimental Study on the Effect of Offset Notch on Fracture Properties of Rock under Three-Point Bending Beam

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Qifeng Guo ◽  
Xinghui Wu ◽  
Meifeng Cai ◽  
Shengjun Miao
Keyword(s):  
Fracture Toughness ◽  
Experimental Study ◽  
Tensile Strength ◽  
Peak Load ◽  
Fracture Properties ◽  
Three Point Bending ◽  
Nominal Strength ◽  
Bending Load ◽  
The Relationship ◽  
Rock Beam

To investigate the effects of offset notch on the fracture properties of rock beam under bending load, granite beam specimens with “one single offset notch” and “central and offset double notches” are made. A series of three-point bending beam tests on the specimens are carried out by controlling the displacement rate of central notch. The whole load-displacement (P-CMOD) curves are obtained. Experimental results show that the larger the distance between the offset notch and beam central is, the larger are the peak load and nominal strength of the specimen. The peak load and nominal strength for the “central and offset double notches” specimens are both larger than those for the “single central notch” specimen. A fracture model considering the effect of offset notch is developed, and the relationship between the offset notch parameter, tensile strength, and fracture toughness is established.

Flexural Behavior of Sandwich Structure with AA 8011 Honeycomb Core and Al 1100 Face Skins

2018 ◽  
Vol 10 (6) ◽  
Author(s):  
M.R. Ashok ◽  
M. Manojkumar ◽  
P.V. Inbanaathan ◽  
R. Shanmuga Prakash
Keyword(s):  
Finite Element Analysis ◽  
Sandwich Structure ◽  
Flexural Behavior ◽  
Bending Test ◽  
Honeycomb Core ◽  
Element Analysis ◽  
Three Point Bending ◽  
The Core ◽  
Flexural Testing ◽  
The Face

This paper details the fabrication and flexural testing of sandwich structure with Aluminium honeycomb core with Aluminium face skins. The material for the face skin is aluminium 1100 and for the core is Aluminium AA8011. The cell size obtained by fabrication is 7mm. The specimen is prepared and tested as per the ASTM standard C393/C393M-11 on a three-point bending test to obtain the ultimate core shear strength and the face skin strength. Finite element analysis is also carried out to validate the experimental test.

scholarly journals Stress Distribution on Sandwich Structure with Triangular Grid Cores Suffered from Bending Load

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Cui Xu ◽  
Huang Yanjiao ◽  
Wang Shou ◽  
Lu Chun ◽  
Fang Luping
Keyword(s):  
Carbon Fiber ◽  
Sandwich Structure ◽  
Honeycomb Structure ◽  
Triangular Grid ◽  
Element Analysis ◽  
Three Point Bending ◽  
Bending Load ◽  
The Finite Element Analysis ◽  
Carbon Fiber Epoxy ◽  
Honeycomb Sandwich Structure

Triangular grid reinforced by carbon fiber/epoxy (CF/EP) was designed and manufactured. The sandwich structure was prepared by gluing the core and composite skins. The mechanical properties of the sandwich structure were investigated by the finite element analysis (FEA) and three-point bending methods. The calculated bending stiffness and core shear stress were compared to the characteristics of a honeycomb sandwich structure. The results indicated that the triangular core ultimately failed under a bending load of 11000 N; the principal stress concentration was located at the loading region; and the cracks occurred on the interface top skin and triangular core. In addition, the ultimate stress bearing of the sandwich structure was 8828 N. The experimental results showed that the carbon fiber reinforced triangular grid was much stiffer and stronger than the honeycomb structure.

scholarly journals Bionic Design of the Bumper Beam Inspired by the Bending and Energy Absorption Characteristics of Bamboo

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Meng Zou ◽  
Jiafeng Song ◽  
Shucai Xu ◽  
Shengfu Liu ◽  
Zhiyong Chang
Keyword(s):  
Energy Absorption ◽  
Bending Strength ◽  
Fracture Prevention ◽  
Mass Reduction ◽  
Bamboo Culm ◽  
Bending Tests ◽  
Bumper Beam ◽  
Three Point Bending ◽  
Bending Load ◽  
Better Than

This study conducted quasistatic three-point bending tests to investigate the effect of bamboo node on the energy absorption, bending, and deformation characteristics of bamboo. Results showed that the node had a reinforcing effect on the energy absorption and bending strength of the bamboo culm subjected to bending load. The experimental results demonstrated that nodal samples (NS) significantly outperform internodal samples without node (INS). Under the three-point bending load, the main failure mode of bamboo is the fracture failure. The node also showed split and fracture prevention function obviously. Based on that, a series of bionic bumper beams were designed inspired by the bamboo node. The FEM results indicated that the performance of bionic bumpers was better than that of a normal bumper with regard to bending strength, energy absorption, and being lightweight. In particular, the bionic bumper beam has the best performance with regard to bending, energy absorption, and being lightweight compared with the normal bumper under pole impact. The characteristic of the bionic bumper beam is higher than that of the normal bumper beam by 12.3% for bending strength, 36.9% for EA, and 31.4% for SEA; moreover, there was a mass reduction of 4.9%, which still needs further optimization.

Large deformation of corrugated sandwich panels under three-point bending

2020 ◽  
pp. 109963622092765 ◽  
Author(s):  
Fukun Xia ◽  
Yvonne Durandet ◽  
T X Yu ◽  
Dong Ruan
Keyword(s):  
Energy Absorption ◽  
Specific Energy ◽  
Mechanical Response ◽  
Sandwich Panels ◽  
Deformation Mode ◽  
Theoretical Models ◽  
Peak Force ◽  
Specific Energy Absorption ◽  
Three Point Bending ◽  
Core Height

Corrugated sandwich panels are widely used in engineering applications for their excellent energy absorption and lightweight. In this research, the mechanical response of aluminum corrugated sandwich panels subjected to three-point bending is investigated experimentally, numerically, and theoretically. In the experiments, the sandwich panels were loaded under two conditions, namely base indentation and node indentation. A parametric study is conducted by ABAQUS/explicit to investigate the effects of geometric configurations (corrugation angle, core height, and core thickness) on the deformation mode, peak force, and energy absorption. Both peak force and specific energy absorption vary with the geometric parameters. Theoretical models are further developed to predict the force–displacement curves of the panels under the two loading conditions. The theoretically predicted crushing force is in good agreement with both the experimental and simulated results. Finally, the non-dominated sorting genetic algorithm II is adopted to optimize the geometric configuration to improve the specific energy absorption and reduce the weight of corrugated sandwich panels.

Failure Mechanism and Energy Absorption of Foam Filled Hybrid Aluminum-Glass/Epoxy Tubes under Three-Point Bending

2021 ◽  
Vol 888 ◽  
pp. 43-48
Author(s):  
Asad A. Khalid
Keyword(s):  
Energy Absorption ◽  
Polyurethane Foam ◽  
Cross Section ◽  
Absorbed Energy ◽  
Three Point Bending ◽  
Cross Section Area ◽  
Section Area ◽  
Bending Load ◽  
Aluminum Tubes ◽  
Foam Filled

Experimental work has been performed on the behaviour of glass/epoxy, aluminum, and aluminum-glass/epoxy empty and polyurethane foam filled tubes subjected to three-point bending. Tubes were of circular and square cross section area. Hand layup method was used to fabricate the tubes. Each tube is made of six layers. Inner diameter and total length of the tubes were 50 mm and 250 mm respectively. Bending load-displacement response, crush force efficiency, and absorbed energy were drawn and discussed. Effect of foam filler, material of the tube and stacking sequence on the maximum bending load was investigated. Energy absorption was determined and discussed. failure mode was investigated. It has been found that the polyurethane foam filler increased the maximum bending load and the energy absorption of the circular and square cross section area tubes. Using hybrid aluminum-glass/ epoxy enhanced the bending load and absorbed energy of the aluminum tubes. Cracks were observed at the upper and lower surfaces at the centre of the glass/epoxy tubes. While the aluminum tubes deformed significantly with either no cracking or with one crack appeared at the centre of the top surface of the tube.

Effect of Grain Size on the Performance of Extruded Magnesium Alloy Tubes in Three-Point Bending

2009 ◽  
Vol 618-619 ◽  
pp. 523-526
Author(s):  
Tim B. Hilditch ◽  
Dale Atwell ◽  
Aiden G. Beer
Keyword(s):  
Grain Size ◽  
Magnesium Alloy ◽  
Energy Absorption ◽  
Carrying Capacity ◽  
Peak Load ◽  
Load Carrying Capacity ◽  
Three Point Bending ◽  
Load Carrying

The performance of extruded AZ31, AZ61 and AM-EX1 tubes was examined in three-point bending. Different extrusion temperatures were used to investigate the effect of grain size on the load-carrying capacity, energy absorption and fracture propensity of the tubes. Results showed that while the peak load increased with a smaller average recrystallised grain size, the retention of large elongated un-recrystallised grains in the microstructure reduced the load. The presence of the large elongated grains also appeared detrimental to the ability of the tube to deform before fracture.

Investigation of sandwich composite failure under three-point bending: Simulation and experimental validation

2018 ◽  
Vol 22 (6) ◽  
pp. 1838-1858 ◽  
Author(s):  
Sudharshan Anandan ◽  
Gurjot Dhaliwal ◽  
Shouvik Ganguly ◽  
K Chandrashekhara
Keyword(s):  
Numerical Model ◽  
Sandwich Structure ◽  
Experimental Validation ◽  
Bending Test ◽  
Core Material ◽  
Scale Model ◽  
Honeycomb Core ◽  
Three Point Bending ◽  
Failure Initiation ◽  
Meso Scale

A sandwich structure consists of a two thin and strong facesheets, bonded to a thick lightweight core material. The mechanical response of a sandwich structure depends on the properties of its constituents. A numerical model and experimental validation of the three-point bending test of sandwich composites are presented in this study. The core material is aluminum honeycomb. The facesheets are made of IM7/Cycom5320-1, which is a carbon fiber/epoxy prepreg system. A comprehensive model of the failure under flexural loading was developed. Facesheet failure was modeled using Hashin’s failure criteria. A detailed meso-scale model of the honeycomb core was included in the model. The experiments indicated that failure initiation was due to local buckling in the honeycomb core. Failure propagation was in the form of core failure, facesheet compressive failure, and interlaminar failure. The developed meso-scale model was able to accurately simulate failure initiation and propagation in the composite sandwich structure. The effect of elevated temperature on the three-point bending behavior was studied numerically as well as experimentally. An increase in test temperature to 100°C resulted in a drop of 9.2% in flexural strength, which was also predicted by the numerical model.

scholarly journals Research on Three-point Bending Mechanical Performance of Square Tube Structure Filled with Foam Aluminum

Mechanika ◽  
2021 ◽  
Vol 27 (6) ◽  
pp. 442-450
Author(s):  
Kun YANG ◽  
Yunjie SHA ◽  
Tao YU
Keyword(s):  
Bearing Capacity ◽  
Energy Absorption ◽  
Mechanical Performance ◽  
Foam Aluminum ◽  
Deformation Degree ◽  
Bending Deformation ◽  
Three Point Bending ◽  
Bending Load ◽  
The Moment ◽  
Tube Structure

In this paper, the quasi-static three-point bending experiments are carried out to study the deformation behavior of square tube and square tube filled with foam aluminum. The difference of bending deformation mode, loading characteristics and energy absorption efficiency between tube and foam aluminum filled tube is compared. And the influence of adhesive between the foam aluminum core and the tube wall on the bending deformation of square tube filled with foam aluminum is analyzed. Based on the bending super beam element model of tube structure, the relationship between the moment and rotation of square tube filled with foam aluminum under transverse static loading is analyzed. And the formula for calculating the moment and rotation angle of square tube filled with foam aluminum at three-point bending is obtained. In order to compare the simulation results, theoretical calculation results and experimental results of quasi-static bending, the three-point bending deformation of square tube and filled with foam aluminum under quasi-static and impact loading is simulated by finite element method. The results show that the filling of foam aluminum can improve the bearing capacity and energy absorption performance of the square tube structure. Under the bending load, the deformation degree of the bearing section is greatly reduced, which increases the bearing capacity of the structure and increases the stability of its bending resistance.

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