Design and Analysis of Sandwich Composite Beam

Design and Analysis of Sandwich Composite Beam

(Thermo-Plastic Skin And Honey Comb Core Sandwich)

R. Pallavi Reddy

M.Tech

Advanced Manufacturing Systems(A M S) Ellenki College of Engineering and Technology Hyderabad, INDIA

B Durga Prasad Assistant proffesor Mechanical engineering

Guru Nanak Institution of Technical Campus Hyderabad, INDIA

Abstract The sandwich-structured composite is which is made of thermo-plastic skin which is been placed above and below the honey comb core which will be like a sandwich structure, which widely used in aerospace and naval applications. In this a sandwich composite for Semi-monocoque construction in aircraft fuselage is analyzed for its strength under different loading conditions. 3D modeling of sandwich composite beam is done in Pro/Engineer and further Static, Modal and Random Vibration analysis is done on the beam using finite element analysis software Ansys.

Keywords Pro/E; Ansys; composite sandwich; static analysis; Modal analysis; Random vibrational analysis;

1. INTRODUCTION

   A sandwich-structured composite is a special class of composite materials that is fabricated by attaching two thin but stiff skins to a lightweight but thick core. The core material is normally low strength material, but its higher thickness provides sandwich composite with high bending stiffness with overall low density [1]. the sandwich-structured composite is which is made of thermo- plastic skin which is been placed above and below the honey comb core which will be like a sandwich structure[3], when any force is applied on the sandwich composite the upper will undergoes compression stress and the lower skin will undergoes tensional stress[2]. The core in between the skins will be resisting the stresses acting on the sandwich and also we can say that increasing the thickness of core material will get stronger. This principle works in much the same way as an I-beam does [4].This kind of sandwich material will be widely used in aerospace and naval applications [5]. So I have chosen a semi monocoque for testing of this sandwich composite [6]. Semi-monocoque construction is an aircraft fuselage. I have designed 3D modeling of sandwich composite beam in Pro/Engineer and further Static, Modal and Random Vibration analysis is done on the beam using finite element analysis software Ansys.

2. DESIGN OF SANDWICH BEAM (SEMI

   MONOCOQUE)

   Design of the of sandwich beam (semi monocoque) is done in Pro/E the 3D model and 2d drawings of sandwich beam (semi monocoque) is

   Fig.1. 3D Model of sandwich beam (semi monocoque)

   Fig.2. 2D Drawing of Sandwich Beam (Semi Monocoque)

3. Analysis of sandwich beam (semi monocoque)

   1. Material properties

      Skin carbon fiber rein forced thermo-plastics Density : 1430 kg/m3 Youngs modulus : 133000Mpa Poissons ratio : 0.3

      Stringers material properties of honey comb Density : 2900kg/m3 Youngs modulus : 165000Mpa Poissons ratio : 0.25

      Fig.3. 3D Model of sandwich beam (semi monocoque) in Anysis

      Fig.4. Generated mesh to design

      After generating mesh to design it has been gone through three types of analysis

      1. Static analysis

      2. Modal analysis and

      3. Random vibrational analysis

   Under two different pressure conditions Condition 1-14 psi

   Condition 2-16 psi

   1. Static analysis of sandwich beam (semi-monocoque)

      Condition 1- pressure (14psi)

      Total deformation

      Fig.5. Total deformation of design14psi pressure

      Von-mises stress

      Fig.6. Von-mises stress of design14psi pressure

      Von-mises strain

      Fig.7. Von-mises strain of design14psi pressure

      Condition 2- pressure (16psi) Total deformation

      Fig.8. Total deformation of design at 16psi pressure

      Von-mises stress

      Fig.9. Von-mises stress of design at 16psi pressure

      Von-mises strain

      Fig.10. Von-mises strain of design at 16psi pressure

   2. Modal analysis of sandwich beam (semi-monocoque)

      Condition 1- pressure (14psi) Total deformation 1:

      Fig.11. Total deformation 1 of design at 14psi pressure (model analysis)

      Total deformation 2

      Fig.12. Total deformation 2 of design at 14psi pressure (model analysis)

      Total deformation 3

      Fig.13. Total deformation 3 of design at 14psi pressure (model analysis)

      Condition 2- pressure (16psi) Total deformation 1

      Fig.14. Total deformation 1 of design at 16psi pressure (model analysis)

      Total deformation 2

      Fig.15. Total deformation 2 of design at 16psi pressure (model analysis)

      Total deformation 3

      Fig.16. Total deformation 3 of design at 16psi pressure (model analysis)

   3. Random vibrational analysis of sandwich beam (semi-monocoque)

   Condition 1- pressure (14psi) Directional deformation

   Fig.17. Directional deformation of design at 14psi pressure (Random vibrational analysis)

   Shear stress Shear strain

   Shear strain

   Fig.18. Shear stress of design at 14psi pressure (Random vibrational analysis)

   Fig.22. Shear strain of design at 14psi pressure (Random vibrational analysis)

4. RESULTS TABLES

   TABLE I. STATIC ANALYSIS

   Pressure condition	Deformation (mm)	Stress (N/mm2)	Strain
   14(Psi)	0.0046335	1.8908	1.24e-5
   16(Psi)	0.00530	2.166	1.43e-5

   Fig.19. shear strain of design at 14psi pressure (Random vibrational analysis)

   Condition 2- pressure (16psi) Directional deformation

   Fig.20. Directional deformation of design at 16psi pressure (Random vibrational analysis)

   TABLE II. MODAL ANALYSIS

   Pressure condition	14 (Psi)	16 (Psi)
   Frequency (Hz)	240.29	240.46
   Deformation 1 (mm)	11.502	11.502
   Frequency (Hz)	240.29	346.99
   Deformation 2 (mm)	11.503	11.505
   Frequency (Hz)	240.46	538.88
   Deformation 3 (mm)	11.504	34.233

   TABLE III. RANDOM VIBRATION ANALYSIS

   Pressure condition	Directional Deformation (mm)	Shear Stress (N/mm2)	Shear Strain
   14 (Psi)	3.86	15017	0.22
   16 (Psi)	6.204	24595	0.3726

   Pressure condition	Directional Deformation (mm)	Shear Stress (N/mm2)	Shear Strain
   14 (Psi)	3.86	15017	0.22
   16 (Psi)	6.204	24595	0.3726

   Shear stress

   Fig.21. Shear stress of design at 14psi pressure (Random vibrational analysis)

5. CONCLUSION

   3D modeling is done in Pro/Engineer. Static, Modal and Random Vibration analysis is done on the beam using finite element analysis software Ansys. By observing the structural analysis results, the deformation, stressand strain values are increasing by increasing the pressure. The deformation and strain values are more. The stress value is less than its respective allowable strength value. By observing the modal analysis results, the deformation values are less when honeycomb is used but the frequencies are more. If the frequencies are increasing, vibrations will increase. By observing the random vibration analysis results, the directional deformation and shear strain are less but the shear stress values are more when honeycomb is used.

6. REFERENCES

1. Lok T. S. and Cheng Q. H., Free vibration of clamped orthotropic sandwich panel. Journal of Sound and &vibration. Volume 229, No. 2, (2000):

2. H G Allen. Analysis and Design of Structural Sandwich Panels. Pergamon: Oxford, 1969.

3. Zhou G., Hill M. and Loughlan J., Damage Characteristics of Composite Honeycomb Sandwich Panels in Bending under Quasi-static Loading. Journal of Sandwich Structures and Materials. Volume 8, No. 1, (2006).

4. Gere, James M (2004). Mechanics of Materials. Thomson Brooks/Cole. pp. 393463. ISBN 0-534-41793-0.

5. Plantema, F, J., 1966, Sandwich Construction: The Bending and Buckling of Sandwich Beams, Plates, and Shells, Jon Wiley and Sons, New York.

6. Janugaon vijay kumar, Static and Dynamic Analysis of Aircraft Stiffened Panel, International Journal of Innovations in Engineering and Technology (IJIET) Vol. 3 Issue 2 December 2013 ISSN: 2319 1058