TOPOLOGY OPTIMIZATION OF AIRCRAFT HATCH LOCK · 2017. 9. 25. · G. Ragul Department of Mechanical...

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International Journal of Mechanical Engineering and Technology (IJMET) Volume 8, Issue 9, September 2017, pp. 86–94, Article ID: IJMET_08_09_009 Available online at http://www.iaeme.com/IJMET/issues.asp?JType=IJMET&VType=8&IType=9 ISSN Print: 0976-6340 and ISSN Online: 0976-6359 © IAEME Publication Scopus Indexed

TOPOLOGY OPTIMIZATION OF AIRCRAFT

HATCH LOCK

S. Harihara Kumaran, V. Jayakumar, F. Mohammed Ajmal Sheriff and A. Pandiyan

Department of Mechanical Engineering, Saveetha School of Engineering, Saveetha University, Chennai, Tamilnadu, India

Shajin Majeed

Technical Consultant-CAE, Tata Technologies, New Delhi, India

G. Ragul

Department of Mechanical Engineering, Budge Budge Institute of Technology, Kolkata, India

ABSTRACT

This paper introduces the optimized design of aircraft hatch lock using topology

optimization powered by ANSYS workbench. This can be achieved by 3D modeling of

hatch lock in any of the software like CAE, FEA etc., where the models can be

imported to the workbench. The main aim of this technique is to reduce the weight of

the material without affecting the factor of safety and improving the efficiency of the

hatch lock without compromising the strength of the material. Topology optimization

includes section of material area where there is no stress acting or minimum stress

acting in it. This technique gives advantage of reducing the material area by topology

optimizing it and reduction in weight to increase the efficiency of the product. This

paper presents topology optimization of aircraft hatch lock, which resulted in the

weight reduction without affecting the component strength and other factors.

Keywords: Aircraft hatch, Topology optimization, Structural analysis, Ansys workbench.

Cite this Article: S. Harihara Kumaran, V. Jayakumar, F. Mohammed Ajmal Sheriff, A. Pandiyan, Shajin Majeed and G. Ragul, Topology Optimization of Aircraft Hatch Lock, International Journal of Mechanical Engineering and Technology 8(9), 2017, pp. 86–94. http://www.iaeme.com/IJMET/issues.asp?JType=IJMET&VType=8&IType=9

1. INTRODUCTION

Topology optimization is a mathematical technique used to optimize the structure. The use of this topology optimization has increased for past few years and the method became easy because of the computer aided design (CAD) software. This technique is widely used in aircraft where the reduction in weight [1] is necessary without affecting the factor of safety. Many automobile sectors have been employing topology optimization for the benefit of reduced cost, material consumption and weight reduction. Factor of safety [2] is that the

Topology Optimization of Aircraft Hatch Lock


ability of the material to withstand the load than the allowable load. When the weight is reduced, the factor of safety also decreases. In order to overcome the drawback, one must ensure that reduction in weight will not affect the factor of safety of material.

The hatch lock is the aircraft component that is used to lock the doors. This paper discusses about the weight reduction without affecting the component strength and other factors. Reduction in weight includes removing the area where there is no stress acting on the area or may be minimal stress acting on it. In case of aircraft weight reduction is necessary because of fuel efficiency. The maximum takeoff weight (MTOW) is the maximum weight at which the pilot is allowed to attempt the takeoff, so weight play a major factor in takeoff fuel efficiency. MTOW is the heaviest weight of the aircraft; here one has to concentrate on aircraft because it is required to reduce weight in order to meet the above consequences. In this work, the topology optimization of hatch lock is presented to analyze the stress concentration of the product. In addition, weight reductions are to be done with many products in aircraft, which is necessary to increase fuel efficiency. This can be done using various CAD software and can be analyzed in ANSYS workbench.

There are many factors to be taken into consideration that it should not affect the factor of safety of the vehicle where the excess load is applied on a body than the allowable load and no compromising in the strength of the material. Topology optimization of hatch lock is performed by applying various loads on the part and analyze the stress on the followed by sectioning the part. Topology optimization of crank case of automobile is presented in [3] which resulted in almost 50% of the material reduction. Aircraft is made of aluminium metal and of many components. In past years they were not in aware of this topology optimization technique so the weight of the aircraft will be more normally. If we use this technique, the weight can be reduced by 50% as aircraft will have many safety factors like 2 engine for safety landing i.e., if one fails to perform the other is used for emergency landing which also add weight to the aircraft so 2 engine is must though it add weight to the aircraft; we must detect the weight such that it should not affect the factor of safety of aircraft. Material interpolation [4] is also done in topology optimization. Aircraft gross weight will decease during a flight due to fuel and oil consumption. The weight includes fuel, engines, wings, body, payload, tail etc. We can also optimize these weights and increase the efficiency of the aircraft. The work envelop of hatch lock to be optimized for the weight reduction of the material in aircraft is shown in figure 1. The plank is an unmachined product with excess materials in it. In design and structural analysis [5], those have to be acted upon stresses by applying loads, make them to deform its shape, remove the materials and then reduce the weight of the component for effective performance. The final product of the material will be 30% weight reduced.

Figure 1 Work envelop of hatch lock

The skeleton diagram shown in figure 2 is the hatch lock with the part to be fitted, where part 1 is simply supported by stiff plate and part 2 is fastened by four high strength bolts (#10-32).

S.Harihara Kumaran, V. Jayakumar, F. Mohammed Ajmal Sheriff, A. Pandiyan, Shajin Majeed and G. Ragul


Base support: The part is bolted against a matting plate of high stiffness.

Bolt interface: The parts are fastened with four #10-32 high strength tension rated bolts as indicated in the specification.

Bearing interface: The parts are loaded through a high stiffness spherical bearing with three load cases:

1. A load of 1,250 lbf applied horizontally.

2. A load of 1,875 lbf applied 45 degrees from the horizontal.

3. A load of 2500 lbf applied vertically.

Parts are intended to be additively manufactured via a laser/powder bed system. Participants shall indicate in their entries the intended printing direction/orientation.

Figure 2 Skeleton diagram of the component

In figure 3 the load is acting horizontally (1,250 lbf).

Figure 3 Load acting horizontally

In figure 4 the inclined load is acting so we resolve those forces into: (i) 1,875 sin 45° = 1,325.85 lbf and (ii) 1,875 cos45° = 1,325.85 lbf.

Figure 4 Inclined load with the horizontal



In figure 5 load is acting vertically (2,500 lbf). In all three load cases the loading shall be applied statically, through a stiff spherical bearing with 0.3125inches in diameter.

Figure 5 Load acting vertically

S.No Requirement Specification

1 Design material 15-5PH per AMS5862 2 Elastic Modulus(E) 29,000KSI=200,000MPa=200GPa 3 Poisson ratio(v) 0.27 4 Yield stress(σy) 145KSI=1000MPa 5 Density(p) 0.283lb/in3=7833kg/m3 6 Minimum geometric feature 0.25 in 7 Minimum wall thickness 0.045in 8 Width of envelop geometry 1.50in=38.11mm

Table 1 Requirements of the hatch lock

The 3D model of the hatch lock is shown in figure 6. Here the plank is unmachined with excess of material those are yet to be removed from the material for the weight reduction as mentioned above. Table 1 projects the specifications for the materials. Those specifications are to be given to hatch lock for its deformation and for topology optimization.

Figure 6 3D model of component

In figure 7 all the specifications mentioned in Table 1 is imposed on the material using ANSYS WORKBENCH. After all loads given to the material, it is then meshed in workbench. If required fine mesh is given to the material.



Figure 7 Meshing of component

Equivalent strain [6] is obtained in figure 8 due to the load. The hatch lock is given specific loads where deformation occurs. Strain is nothing but the change in length to the original length.

Figure 8 Equivalent strain

Equivalent stress [6] is obtained in figure 9 where the load is acting on the area. The hatch lock is given different loads on the bearings.

Figure 9 Equivalent stress

The deformation occurs in figure 10 when the load is applied to hatch lock. Here the different colors show the range of stress acting on the hatch lock.



Figure 10 Deformation of the component

Here the 20% of the materials to be removed from the hatch lock is observed from above figure 11, the brown color is material to be removed rest is to be kept. After the materials has been removed the mass of the hatch lock is 300.63g.

Figure 11 20% of the materials to be removed

In figures 12.1 and 12.2 materials to be removed from the hatch lock are displayed. This shows that the areas are stress free.

Figure 12.1 Materials to be removed

Figure 12.2 Materials to be removed



The material to be kept is displayed in figures 13.1 and 13.2 where the stress is more when we apply load. The mass of the material before optimization is 826.36g. The weight has been reduced.

Figure 13.1 Material to be kept

Figure 13.2 Material to be kept

In order to increase the efficiency of aircraft the components weight must be reduced which should not affect the factor of safety, Factor of safety before material removal is shown in figure 14.

Figure 14 Factor of safety before material removal

Topology optimization [7-8] aim is to reduce the material weight without affecting the factor of safety of that material. The factor of safety after material removal is shown in figure 15.

Figure 15 Factor of safety after material removal



The hatch lock is obtained after the stress consideration and removal of weight from the material. Again the material is meshed for further reduction of material and the final product weight is reduced to 300.63g from the actual weight of 826.36g which is observed from the figure 16.

Figure 16 Mesh on final product

The final product is obtained with 70% of weight reduction from the hatch lock as shown in figure 17.

Figure 17 Final product

2. CONCLUSIONS

In this work, the weight of the hatch lock material is reduced without affecting the factor of safety and without compromising the strength of the material. The hatch lock weight is reduced by 525.73g after topology optimization, due to which the efficiency of the aircraft will be increased. The initial mass of the plank is 826.36g which is unmachined and the factor of safety considered for the aerospace industries is 1.2-1.3. The remodeling of the product is done using the topology optimization. The final product obtained has the mass of 300.63g; about 525g of weight is reduced from the product by the above method. The result obtained is 76% of weight reduction from the product, which in turn will improve the fuel efficiency and thus the efficiency of the aircraft without affecting the factor of safety.



REFERENCE

[1] Richard Holzwarth, The structural cost and weight reduction potential of more unitized aircraft structure. 39th AIAA/ASME/ASCE/AHS/ASC, Structures, Structural Dynamics, and Materials Conference and Exhibit, 1998.

[2] John J. Zipay, Clarence T. Modlin, Curtis E. Larsen, The Ultimate Factor of Safety for Aircraft and Spacecraft-Its History, Applications and Misconceptions (AIAA 2016-1715) 57th AIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, 2016.

[3] A. Pandiyan, G. Arun Kumar, B. Baskar, A. Shajin, A. Sathis Kumar and Mohammed Saleem. Thermal Effect On Topology Optimized Crank Case Cover For Additive Manufacturing. ARPN Journal of Engineering and Applied Sciences, Vol. 11, No. 18, pp. 11098-11103.

[4] Raguram A, Nivya N and Ashok Kumar L, A Study of Different Converter and Maximum Power Point Tracking Topology, International Journal of Mechanical Engineering and Technology 8(8), 2017, pp. 1173–1182

[5] M. Ramanareddy, N. S. Murthy sarma, P. Chandrasekhar, A Novel Cmos Model Design For 2-6 Ghz Wideband Lna Input Matching Using Resistive Feedback Topology for Wimax Applications, International Journal of Electronics and Communication Engineering & Technology (IJECET), Volume 5, Issue 8, August (2014), pp. 55-60

[6] Raj Kumar Tiwari, Sachin Kumar and G R Mishra, A Class Ab Ccii Topology Based on Differential Pair with Modified Output Stage, International Journal of Electrical Engineering & Technology (IJEET), Volume 4, Issue 1, Jan-Feb (2013), pp. 68-74

[7] M. P. Bendsùe, O. Sigmund. Material interpolation schemes in topology optimization Archive of Applied Mechanics 69, Ó Springer-Verlag 1999, pp. 635-654.

[8] G. Ragul, G. Kalivarathan, V. Jayakumar, Praveen Maruthur, Into Jacob and S. Naveen Kumar. An Analytical Investigation on Design and Structural Analysis of Cam Shaft using Solid Works and Ansys in Automobiles. Indian Journal of Science and Technology, Vol. 9, No. 36, pp. 1-9.

[9] J. Vandenkerckhove and G. Lampens. Stress and Strain Analysis of Cylindrical Case-Bonded Grains. Solid Propellant Rocket Research, 1960. pp. 121-138.

[10] Martin Philip Bendsoe. Topology Optimization: Theory, Methods, and Applications ISBN: 3662050862, 9783662050866.

[11] R. Mcanally Air Superiority Fighter wing design for cost and weight reduction. 15th Structural Dynamics and Materials Conference, 1974, 10.2514/6.1974-338.

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